The technological process for the preparation of concrete mixtures. Typical technological map (ttk) Requirements for quality and acceptance of works
ROUTING
PREPARATION OF CEMENT CONCRETE MIXTURE
IN CONTINUOUS MIXING PLANT SB-78
The technological map was developed by the department for the introduction of advanced experience and technical regulation in the construction of highways and airfields (performer T.P. Bagirova) based on the materials of the Rostov research vessel of the Institute "Orgtransstroy".
I. SCOPE
The technological map is developed on the basis of the methods of scientific organization of labor and is intended for use in the development of a project for the production of work and the organization of labor on mixing plants for the preparation of cement concrete mixtures.
The following basic conditions are accepted in the card.
The automated plant with the SB-78 mixing unit works in the general complex of machines and mechanisms for the arrangement of cement-concrete pavements of highways.
Consumable warehouse of sand and fractionated crushed stone open type with dividing walls located next to the mixing plants. The warehouse must have a stock of materials sufficient to operate the units for 10 days. Sand and graded crushed stone are delivered to the consumable warehouse in railway cars or by road. In the case of delivery of unfractionated or contaminated crushed stone, washing and sorting of material into fractions should be organized. Sand and crushed stone are fed to the feeders of the dispensing department with bucket loaders such as TO-18 or Case.
The mixing plant is supplied with cement from a 300-ton consumable warehouse.
Cement is delivered to the consumable warehouse by auto cement trucks.
The site of the plant has a hard surface, a drainage system is provided. The territory of the plant is fenced with a temporary fence. The plant is supplied with water and electricity.
The mixing plant has a paved access road. The movement of cars is organized in a ring pattern without oncoming traffic.
A column of dump trucks with an estimated number of cars is fixed for the removal of the cement-concrete mixture.
The number of vehicles is adjusted depending on the range of transport of the mixture and road conditions.
The technological map provides for the installation capacity of 320 m3 per shift.
When changing the conditions adopted in the technological map, it is necessary to link it to the new conditions.
II. PRODUCTION TECHNOLOGY INSTRUCTIONS
The automated cement concrete plant (CBP) with the SB-78 unit is designed for the preparation of hard and plastic concrete mixtures with aggregate fractions up to 40 mm in size.
Technical specifications
Productivity, m3 / h. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .60
Number of aggregate fractions:
sand. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .1
crushed stone. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .3
The largest size of the filler, mm. ... ... ... ... ... ... ... ... ... ... ... ... ... ... .70
Capacity of service bins, m3:
placeholders. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .36
cement. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .12
Installed power, kW. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 57.8
Overall dimensions, mm :
length. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 36800
width. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .2600
height. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 12520
Weight, t. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .3
The installation consists of the following main blocks (see figure):
a continuous-action concrete mixer, the working body of which is square shafts with cast blades of 35GL steel mounted on them. The working surfaces of the blades are located at an angle of 45 ° relative to the axis of the shaft;
a cement supply hopper, which is a cylindrical-conical container and is intended for receiving cement and feeding the dispenser with cement. The bunker is equipped with a filter for cleaning exhaust air before it is removed to the atmosphere and automatic indicators of the lower and upper levels;
dosing unit, consisting of four supply hoppers for crushed stone and sand with dosing units. A V-21 vibrator is attached to the inclined wall of the sand bin. The batchers are installed above a horizontal collecting conveyor, through which materials are fed to the inclined conveyor, and then to the concrete mixer.
Process flow diagram of the pulp and paper mill operation with the SB-78 mixer:
1 - feeders; 2 - conveyors; 3 - two-armed estrus;
4 - aggregates bins; 5 - aggregate batchers;
6 - collecting conveyor; 7 - inclined conveyor;
8 - cement bin; 9 - filter; 10 - cement batcher;
11 - upper estrus; 12 - lower estrus;
13 - concrete mixer truck; 14 - calibration dispenser;
15 - storage hopper; 16 - mixer;
17 - a hose for diverting water to a concrete mixer;
18 - three-way valve; 19 - water tank;
20 - water dispenser
The mixing plant is equipped with dosing devices for cement, water and additives.
The installation is controlled from the driver's cab, and the electrical equipment is located in a special room. The driver's cab is equipped with devices that record the progress of the technological process.
Preparing the mixing plant for operation
Before the start of the release of the cement-concrete mixture, the following operations are performed:
check for the presence of cement, aggregates, water and additives in the supply containers;
include the supply of electricity;
check the serviceability of the dispensers;
give the installation driver the composition of the cement-concrete mixture, selected by the laboratory in accordance with the moisture content of the materials;
the weighing devices of the dispensers are installed in accordance with the composition of the mixture.
Before turning on the units of the installation, the driver gives two warning sound signals with an interval of 1 minute (the first signal is long, the second is short).
After that, the units of the installation are put into operation in the following order:
concrete mixer, metering pump (in a ring pattern), inclined conveyor, collecting conveyor, aggregate batchers, cement batcher, three-way valve with water supply to the mixer.
After 1 - 2 minutes after the start of idle work, they begin to release the mixture.
First, test mixes are made in a semi-automatic mode.
At this moment, the driver and laboratory assistant determine the mobility of the mixture (cone draft) by sampling. If the slump of the cone differs from the specified one, then the dosage of water is changed.
Having achieved the specified slump of the cone and making sure of the correct dosage of the constituent materials, the driver switches the plant to automatic operation.
Preparation of the mixture
The plant operates according to the following scheme.
With single-bucket loaders, crushed stone of two fractions and sand are fed from stacks located in an open area to the supply bins.
Crushed stone and sand are continuously dosed by tape pendulum dispensers C-864, to which material is supplied from feed bins. Then the materials go to the collecting conveyor. First, crushed stone of fraction 20 - 40 mm is fed to the belt, and then crushed stone of fraction 5 - 20 mm and sand. This dosing and feeding order eliminates the adhesion of small particles of material to the conveyor belt. From the collecting conveyor, the materials go to the inclined conveyor. From the inclined conveyor, the dosed materials are fed through the hopper to the mixer.
Cement from the supply hopper through the SB-71 cement weighing batcher goes directly to the mixer.
Water is metered by a metering pump and supplied through a pipeline directly to the mixer.
When preparing a concrete mixture, surface-active additives are introduced that increase the frost resistance of concrete and the workability of the concrete mixture, as well as reduce the water demand of the mixture and the consumption of cement. The additives are prepared in a special installation. The calculation is based on dry matter. To prepare 1 m3 of the mixture, a plasticizing additive is introduced into the water - sulphite-yeast mash (SDB) in an amount of 0.2 - 0.25% and sodium abietate (neutralized air-entraining resin - SNV) in an amount of 0.02 - 0.03% of the weight of cement and together with water is fed into the mixer.
In the mixer, the concrete components are intensively mixed and transported by paddle shafts to the outlet. From the mixer, the finished mixture first enters the storage hopper, and then through the jaw gate is discharged into dump trucks.
At the end of the day, after the concrete mix is finished, the entire team starts cleaning the units of the concrete mixing plant. The mixer is especially thoroughly cleaned.
At first, crushed stone is fed into the mixer and dry cleaning is carried out, then the mixer is washed with water, and the jaw gate of the storage hopper is also cleaned.
The rest of the components of the plant are cleaned with compressed air.
During the shift and at the end of the work, the access roads and the plant area are periodically watered to reduce dust. The bulldozer removes the remnants of the spilled cement-concrete mixture from under the mixers.
Quality requirements
The components of the concrete mix immediately after entering the concrete plant are monitored by the laboratory of the CBZ and the Central Laboratory of the Construction Administration. The quality of the materials is checked by visual inspection and by sampling and testing of samples.
Every day, at the beginning of the first shift, a representative of the CPB laboratory checks the correct operation of the dispensers. The weighing device is installed in accordance with the composition of the concrete mixture approved by the chief engineer of the control system and taking into account the moisture content of the aggregates.
Only laboratory personnel are allowed to open weighing cabinets and dosing devices.
The prepared cement-concrete mixture must have a well-chosen granulometric composition, possess the necessary mobility or rigidity during compaction.
The mixture must meet the requirements of GOST 8424-72 "Road concrete".
The quality of the cement-concrete mixture obtained in the SB-78 mixing plant primarily depends on the continuity of its operation, since at each stop the calculated ratio of the components of the concrete mixture, especially cement and water, changes.
With the same composition of the mixture and the correct dosage, the mobility, workability, volumetric weight and concrete yield must be constant.
When the cement concrete mixture is released, the mobility of the mixture (cone draft) is monitored at least 5 times per shift (once an hour and each time with a sharp change in the cone draft), and the volumetric weight, the actual composition of concrete, the quality of additives, the content of dusty and clay impurities in the crushed stone and sand - once a shift.
Safety instructions
Persons who have reached the age of 18, have completed a training course, have the right to operate the mixing plant and its aggregates and are familiar with the safety regulations are allowed to work on the mixing plant.
All personnel servicing the installation must be provided with overalls and personal protective equipment.
Before starting the plant, it is necessary to test the operation of the units at idle speed.
The plant must be equipped with a reliable audible alarm.
Open live parts of shields, contact parts of plug connections, switches and switches of electrical machines must be protected by covers or casings.
It is prohibited to make minor repairs while the plant is in operation. The concrete mixer should be cleaned, lubricated and repaired only after the plant is shut down.
In case of a sudden stop of one of the working units of the technological complex, the rest of the units of the plant should be immediately turned off, first towards the point of loading the material, and then towards the unit for unloading the cement concrete mixture.
Before stopping the concrete mixer, it is necessary to stop the supply of materials to it. At the beginning of the working day or after plant shutdowns due to malfunctions, the mixer driver should only switch on individual units of the plant as directed by the duty mechanic.
When preparing a cement-concrete mixture, one should be guided by the following regulatory documents and literature:
SNiP I-V.2-62 "Inorganic binders and additives for concrete and mortars". Gosstroyizdat, M., 1963
SNiP I-B.1-62 "Aggregates for concrete and mortar". Gosstroyizdat, M., 1963
"Instructions for the construction of cement-concrete pavements of highways". VSN 139-68 / Ministry of Transport, Transport, Moscow, 1968
"Safety regulations for the construction, repair and maintenance of highways". "Transport", M., 1969.
III. LABOR ORGANIZATION INSTRUCTIONS
Work on the preparation of the cement-concrete mixture is carried out in two shifts.
In each shift, the mixing plant must be serviced by a team of 6 people, including: mixer driver 6 bits. - 1; driver's assistant (construction locksmith) 4 digits - 1; operator of a single-bucket loader TO-18 5 razr. - 1; compressor driver 4 bit - 1; component dispenser 3 bit - 1; electrical fitter 5 bits - 1. The driver of the bulldozer 5 digits. and an auxiliary worker 2 bits. are not included in the link and are paid separately.
The mixer operator controls the installation during operation, gives warning sound signals before turning on the units, turns on the units of the installation.
An assistant driver (construction locksmith) monitors the availability of materials in the supply bins, lubricates the units, checks the condition of the hoses, monitors the serviceability of the units and units of the installation.
The driver of the TO-18 loader prepares the machine for operation, ensures uninterrupted supply of materials to the conveyor feeders, and provides maintenance of the loader.
The compressor operator ensures uninterrupted supply of cement to the cement feed hopper.
An electrician monitors the technical condition of power electrical equipment and eliminates all faults.
The component dispenser checks for aggregates in the feed bins and dispenses additives according to the recipe.
Workers not included in the brigade perform the following work:
During the shift, the bulldozer driver pushes crushed stone and sand to the loader's working platform, monitors the condition of the access roads to the plant, and at the end of the shift removes the remnants of the spilled mixture under the mixer.
An auxiliary worker regulates the approach of dump trucks for loading, keeps records of the prepared mixture and draws up invoices.
IV. PRODUCTION PROCESS SCHEDULE
(preparation of cement concrete mixture on the SB-78 unit,
shift capacity 320 m3)
┌────────────────┬──────┬─────┬───────┬────────────────┬───────────────────────────────┐
│NameUnit- │Volume│Labor- │Composition of the link│Production time│
│operations│unit│work│capacity│ (teams) │process│
││ism f- │for 2 │for the whole│├───────────────┬──────────────┤
││ I shift II shift
││││work, │├─┬─┬─┬─┬─┬─┬─┬─┼─┬─┬─┬─┬─┬─┬─┬─┤
││││people .- h ││1│2│3│4│5│6│7│8│1│2│3│4│5│6│7│8│
├────────────────┼──────┼─────┼───────┼────────────────┼─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┤
│Preparatory│││2,0│Machinist││
│mixer work││
├────────────────┼──────┼─────┼───────┤ 6 bit - 1││
│Cooking│100 m3│ 6.4 │90│Help
│cement concrete││││machinist││
│and concrete mix││││ (locksmith││
│ (material supply - ││││building) ││
│lov in consumables ││││ 4 bits. - 1││
│bunker, ││││Machinist││
│continuous ││││loader TO-18││
│dosing││││ 5 bits - 1││
│materials, ││││Machinist││
│material supply ││││compressor│Figure│
Trial and water 4 bits - 1││
│in the mixer, ││││dosing device││
│ mixing and components││
│ release finished ││││ 3 bit. - 1││
│mixtures) ││││Electrical fitter││
├────────────────┼──────┼─────┼─────── - 1││
│Stop│-│-│1,0│││
│ mixing
│ settings for ││││││
│shift change││││││
├────────────────┼──────┼─────┼───────┤││
│ Final-│-│3,0│││
│work (cleaning ││││││
│and flushing││││││
│ mixer, ││││││
│cast││││││
│ in order││││││
│doorways││││││
│paths) ││││││
└────────────────┴──────┴─────┴───────┴────────────────┴───────────────────────────────┘
Total for 640 m 396
Total for 100 m3 15
Notes. 1. Numbers above the line - duration of operations in minutes.
2. The labor intensity includes time for rest during the shift in the amount of 8% of the work time.
3. Daily preventive maintenance is carried out at night by a special repair team.
V. CALCULATION OF COOKING LABOR COSTS
CEMENT CONCRETE MIXTURE IN MIXER SB-78
(shift capacity 320 m3)
────────┬─────────────────────┬──────────────┬──────┬─────┬─────┬─────────┬───────┬─────────
Code│Description of work│ Composition of the link │Unit- │Volume
norms││ (brigades) │nice│work│time- │rub.-kop.│active │ costs
│││ism e- name ││time│work
│││reniya ││││na ves│ the whole
│││││││volume│volume
│││││││ works, │ works,
│││││││person - h │rub.-kop.
────────┼─────────────────────┼──────────────┼──────┼─────┼─────┼─────────┼───────┼─────────
Local │Checking of SB-78 units │Machinist│100 m3│ 6.4 │15.6 │10-62│ 99.84 │67-97
the norm before starting work. │with mixing
SU-921│Adjusting the dispenser│installation││││││
trust cement and check 6 bit. - 1││││││
"Dondo r- the work of all│Help
system of "dispensers. Checking the" operator "
│working knots│ (locksmith││││││
│ idle. Checking│construction) ││││││
│quality produced│ 4 bits - 1││││││
│concrete and│Machinist││││││
│ feed correction │ front ││││││
│water and cement. │n loader││││││
│Cooking and│ "Case" ││││││
│ release of commercial │ 6 bit. - 1 ││││││
│ concrete in │Locksmith││││││
│automatic │on feeding││││││
│mode. Bringing to "cement"
│order of jobs │ 4 digits - 1││││││
│and mixing road
│installation at the end│working software ││││││
│shifts. Service│maintenance││││││
│installations, monitoring│dosing devices││││││
│for technical│inert││││││
│the state of the power │materials││││││
│equipment│ 3 bits - 1││││││
││Electrical fitter│││ │││
││ 5 bit - 1││││││
────────┴─────────────────────┼──────────────┼──────┼─────┼─────┼─────────┼───────┼─────────
Total: for 640 m3 99.84 │67-97
per 100 m3││││││ 15.6│10-62
Vi. TECHNICAL AND ECONOMIC INDICATORS
──────────────────────────┬──────────┬────────┬─────────┬──────────────────
Name of indicators │ Unit By cal-│Po│N and how many%
│measurements │kulation │ graph B │indicator by
││А││graph more (+)
││││ or less (-),
││││ than according to the calculation
││││B - A
││││ (----- x 100%)
││││A
──────────────────────────┼──────────┼────────┼─────────┼──────────────────
Labor intensity of work│people - h│15.6│15│-3.8
per 100 m3 of mixture
Average category of workers-│4.5│4.5│-
Average daily wage RUB - kopeck │5-48│5-66│ + 3.2
pay of one worker││││
Utilization factor K in 0.86│0.86│-
time settings││││
Production of one worker m3│52│53│ + 1.9
Vii. MATERIAL AND TECHNICAL RESOURCES
A. Basic materials
The consumption of materials is determined according to the recipe for the cement-concrete mixture. This table shows the average material consumption.
────────────────────────────┬────────────┬────────────┬────────────────────
Name of materials│GOST│Unit│Amount of mixture
││ measurements├─────────┬──────────
│││per 100 m3│ per shift
││││320 m3
────────────────────────────┼────────────┼────────────┼─────────┼──────────
Cement M-400│10178-62│t│38│121.6
Sand│8736-67│m3│40│128
Crushed stone of fraction 5 - 20 mm│8267-64│m3│33.8│108.2
Crushed stone of fraction 20 - 40 mm│8267-64│m3│33.8│108.2
Water│2874-54│t│14│44.8
Additive SDB│-│kg│76│243.2
Additive SNV│-│kg │7.6│24.3
B. Machines, equipment, tools, inventory
Mixing unit SB-78. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1
Front-end loader TO-18. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1
Bulldozer D-271. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1
Compressor ZIF-VKS-5. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1
Installation for the preparation of additives. ... ... ... ... ... ... ... ... ... ... ... ... 1
Water tank 50 m3. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1
The technological process for the preparation of concrete mixtures consists of the operations of receiving and storing the constituent materials (cement and aggregates), dosing and mixing them, and delivering the finished concrete mixture to vehicles. Sometimes this technological cycle includes additional operations. So, when concreting structures in conditions of negative temperatures, it is necessary to heat aggregates and water; when using concretes with additives (antifreeze, plasticizing, pore-forming, etc.), an aqueous solution of these additives should be prepared beforehand.
According to the degree of readiness, concrete mixtures are subdivided into: ready-to-use concrete mixtures (BSG); partially closed concrete mixtures (BSChZ); dry concrete mixes (BSS).
The main technological task in the preparation of concrete mixtures is to ensure the exact correspondence of the finished mixture to the given compositions.
The composition of the concrete mixture must provide the properties specified for it, as well as the properties of the hardened concrete, therefore, at least twice a day, the factory laboratory takes a sample and gives the characteristics of the produced concrete mixture.
The cement must have a factory passport; when stored for more than 3 months, its activity is checked. It is forbidden to store cements of different brands and types nearby.
The suitability of water for the preparation of a concrete mixture is checked in a laboratory way.
The concrete mixture is made in concrete mixers, which are divided according to the method of loading the components and dispensing the finished mixture to continuous mixers, in which the mixture is loaded and dispensed continuously, and cyclic, in which the work occurs in a cycle: loading - mixing - unloading.
According to the mixing method, there are gravity and forced mixing mixers. V gravity concrete mixers free fall, the mixer drum is set in rotation after loading the components and water into it. The materials loaded into the drum, entrained by the blades of the drum, are mixed. V forced mixing mixers a vane shaft is placed, during the rotation of which the mass is mixed. In addition, the turbine counterflow, in which the bowl rotates, belongs to the concrete mixers with forced mixing.
The size of concrete mixers is determined by the useful capacity of the mixing drums, which is determined by the total volume of dry materials loaded per batch. The geometric volume of the mixing drum exceeds its useful capacity by 3-4 times. During mixing in the mixing drum of the components of the concrete mixture, its small parts (cement, sand) fill the voids between the grains of the coarse aggregate (gravel, crushed stone), and the volume of the finished mixture decreases in comparison with the sum of the volumes of the loaded components. Currently, the characteristics of concrete mixers are given by the volume of the finished mixture.
In continuous mixers, the drum is open on both sides. The supply of materials and the dispensing of the finished mixture occur continuously. Such mixers with forced mixing are used when it is necessary to supply the concrete mixture continuously, such as, for example, when transporting it with a concrete pump.
The concrete mix is prepared using a complete or dismembered technology. With a completed technology, a ready-made concrete mixture is obtained as a product, with dismembered - dosed components - a dry concrete mixture.
The main technical means for the preparation of concrete mixture are supply bins with distribution devices, batchers, concrete mixers, systems of internal vehicles and communications, a distribution bunker.
Technological equipment is assembled according to a one-stage (vertical) or two-stage (parterre) scheme (Figure 13.1). The vertical scheme is characterized by the fact that material elements (cement, aggregates) are once raised to the required height, and then, under the action of their own mass, they move along the technological process. In a two-stage scheme, the components of the concrete mixture are first lifted into the supply hoppers, then they are lowered by gravity, pass through the batchers, enter the common receiving funnel and rise again to be loaded into the concrete mixer.
Rice. 13.1. Layout schemes for concrete mixing plants:
a) one-stage (vertical); b) two-stage (parterre);
1 - conveyor of aggregates warehouse; 2 - conveyor for feeding aggregates into supply bins; 3, 9, 10 - rotary, guide and distribution funnels; 4 - consumables
bunker; 5 - pipe for pneumatic supply of cement; 6 - cement batcher; 7 - dispenser
placeholders; 8 - water dispenser; 11 - mixer; 12 - distributing hopper (piggy bank); 13 - concrete truck; 14 - cement truck; 15 - skip lift
The preparation of concrete mixtures, depending on the specific conditions, should be carried out at concrete plants, concrete batching plants for precast concrete products enterprises, as well as on-site concrete batching plants. If the object is remote from the place of concrete preparation at a distance that does not allow transporting the ready-made concrete mixture without irreversible loss of quality, its preparation should be carried out in concrete mixers loaded with dry dosed components or highly mobile concrete preparation plants.
The choice of the most technologically advanced and economical option for organizing the preparation of concrete mixtures should be made taking into account:
remoteness of the construction site from the points of preparation of concrete mixtures;
type of road surface;
volume and intensity of concrete work;
technological capabilities of the used concrete mixing equipment, etc.
District factories supply ready-made mixtures to construction objects located at distances not exceeding the technologically permissible distance of road transport. This distance, called the radius of the plant, depends on the processing properties of the cement and local road conditions. The district plant usually serves construction sites located within a range of up to 25 ... 30 km.
The regional factories are designed to produce 100 ... 200 thousand m 3 of concrete mixture per year. The technological equipment is arranged vertically. The plant includes a concrete mixing shop, consisting of one, two or three concrete mixing plants (sections), each of which is designed for independent work. Such installations are a tower-type structure with metal frame, having a rectangular shape in plan, and an adjacent inclined gallery for a belt conveyor.
The main assembly units of the installation (for example, a single-section concrete mixing plant with two concrete mixers with a capacity of 20 m 3 / h) are a belt conveyor, a rotary funnel, an elevator, a set of batchers (cement, aggregates and water), feed bins, a receiving funnel, concrete mixers and distribution bins.
The aggregates of the four fractions are fed to the fourth floor of the tower by a belt conveyor and, using a rotary funnel, are directed to the corresponding compartments of the bunkers. The cement is fed by a horizontal screw conveyor and an elevator and is directed through the distribution chutes to one of the two compartments of the bunker in accordance with the brand.
Level indicators, provided in the bins' compartments, signal that they are filled with materials. On the third floor of the tower there is a dosing department, in which two aggregate batchers, one cement batcher and two water batchers are installed. The dosed materials enter the hopper and then into the mixing drums located on the second floor.
The dispensers and mixers are controlled from the consoles located on the third and second floors, respectively. The ready-mixed concrete is discharged from the concrete mixers into the distribution hoppers.
Plants also prepare dry commodity mixtures. In this case, concrete mixtures in a special container are delivered by ordinary vehicles to the place of consumption and prepared at the facility in concrete mixers or during transportation in concrete mixers. Regional factories are economically justified if in the area of their operation the consumption of products is guaranteed for 10 ... 15 years.
Onsite factories usually serve one large construction site for 5 ... 6 years. Such plants are assembled-collapsible block construction, which makes it possible to relocate them in 20 ... 30 days on trailers with a carrying capacity of 20 tons.
Construction concrete mixing plants serve one construction site or a separate facility with a monthly demand for concrete up to 1.5 thousand m 3. Installations are arranged according to the parterre scheme (Fig. 13.2).
Rice. 13.2. Scheme of the inventory concrete mixing plant:
1 - boom scraper; 2 - bunker for cement; 3 - dosing and mixing unit;
4 - skip hoist; 5 - bucket of the loading device;
6 - sector warehouse of aggregates
Mobile concrete mixing plants are also used as building structures, which are mounted on a special semitrailer and have a capacity of up to 20 m 3 / h. The design of the units allows them to be brought into transport position during the shift and transported by tow to the next object. The use of such installations is especially advisable at large dispersed objects located from concrete plants at distances exceeding technologically permissible. Such installations increase the flexibility of the system for the centralized supply of ready-mixed concrete to construction sites.
22. Technology of concrete mix preparation
The technological process of concreting structures includes preparing a concrete mixture and transporting it to a facility under construction, feeding, distributing, laying and compacting it in a structure, taking care of concrete during the hardening process.
The concrete mix cannot be prepared in advance and transported over long distances. After preparation, it must be delivered and placed in the building blocks before setting (usually 1 ... 3 hours). Therefore, the concrete mixture must be prepared near the places of its laying so that the time spent on the road in the summer does not exceed 1 hour.
The concrete mixture is prepared at a mechanized or automated concrete plant in finished form, delivered to construction or prepared at on-site inventory (mobile) concrete mixing plants.
Preparation of concrete mix consists of the following operations: reception and storage of constituent materials (cement, aggregates), weighing (dosing) and mixing them with water and delivery of ready-mixed concrete to vehicles. In winter conditions, this technological process includes additional operations.
The concrete mix is prepared using a complete or dismembered technology. With a completed technology, a ready-made concrete mixture is obtained as a product, with a dismembered one - dosed components or a dry concrete mixture. The main technical means for the release of concrete mixture are supply bins with distribution devices, batchers, concrete mixers, systems of internal vehicles and communications, a distribution bunker.
Stationary technological equipment for the preparation of concrete mixture can be solved according to one-stage and two-stage schemes.
A single-stage (vertical) scheme (Fig. 6.1, a) is characterized by the fact that the constituent materials of the concrete mixture (binders, aggregates, water) rise to the top point of the technological process once and then move downward under the action of their own gravity during the technological process. Advantages: compact, economical, and disadvantages - the complexity of installation (due to the considerable height, up to 35 m).
With a two-stage (parterre) scheme (Fig. 6.1, b), the rise of the constituent materials of the concrete mixture occurs twice, i.e. the constituents of the concrete mixture are first raised into the supply bins, then they are lowered by gravity, passing through their own batchers, fall into the common receiving funnel and again rise up to be loaded into the concrete mixer. The advantage of this scheme is the lower cost of installation, and the disadvantage is big square development.
When the need for a concrete mixture is not more than 20 m 3 / h, mobile concrete mixers with gravity-type mixers are usually used.
Rice. 6.1. Layout schemes for concrete mixing plants and installations: a - single-stage; b - two-stage; 1 - conveyor of aggregate warehouse
in the supply bins; 3, 9, 10 - rotary guide and distribution; 4 - consumable bunkers; 5 - cement supply pipeline; 6 - cement batcher; 7 - aggregate batcher; 8 - water dispenser; 11 - concrete mixers; 12 - distributing hopper; 13 - concrete truck; 14 - auto cement truck; 15 - skip lift.
The design of concrete mixing plants allows you to transfer from the working position to the transport position during one work shift and transport them on a trailer to the next object. The use of such installations is advisable at large dispersed objects located from stationary concrete plants at distances exceeding technologically permissible.
Concrete plants usually produce two types of products - dosed components and ready-mixed concrete.
As equipment for the preparation of conventional concrete mix, mixers of cyclic and continuous action are used.
Batch-type concrete mixers differ in the volume of the finished mixture dispensed in one batch.
Cyclical concrete mixer performance
P = q n k w / 1000, m 3 / h
where q is the volume of ready-mixed concrete for one batch, l; n is the number of batches per hour; k in - the coefficient of use of the concrete mixer in time (0.85 ... 0.93).
The batch mixer is loaded in the following sequence: first, 20 ... 30% of the required amount of water is fed into the mixer, then cement and aggregates are simultaneously loaded, without interrupting the water supply to the required amount. Cement is fed into the mixer between batches of aggregate, thereby eliminating overspray. The duration of mixing the concrete mixture depends on the capacity of the mixer drum and the required mobility of the concrete mixture and ranges from 45 to 240 s.
Continuous concrete mixers are produced with a capacity of 5, 15, 30 and 60 m 3 / h, and gravity-type machines with a drum mixer - with a capacity of 120 m 3 / h. The duration of mixing in these concrete mixers is indicated in the passports of the machines.
When preparing a concrete mixture using a separate technology, the following procedure must be observed: water, part of the sand, finely ground mineral filler (if used) and cement are dosed into the mixer. All these components are thoroughly mixed, the resulting mixture is fed into a concrete mixer, pre-loaded with the remaining part of sand and water, a large aggregate, and once again the whole mixture is mixed.
The composition of the concrete mixture must provide the properties specified for it, as well as the properties of the hardened concrete.
Certain requirements are imposed on the concrete mixture:
1) it must maintain uniformity (during transportation, reloading and laying in formwork), which is ensured by connectivity (non-segregation) and water-holding capacity. All this is achieved by the right selection mixture composition, the accuracy of the dosage of the components and thorough mixing of all components;
2) be workable. Workability is the ability of a concrete mixture to flow and fill a mold under the influence of vibration. It depends on the grain composition of the mixture, the amount of water, the degree of reinforcement, methods of transporting and compaction of the mixture.
Dry building mixture (ССС) is increasingly used - a mixture of binder, aggregates, additives, pigments, dosed and mixed at the factory, and mixed with water before use. Accurate dosing of components allows you to obtain higher technical characteristics of the finished product in comparison with the mixtures obtained, prepared at the construction site. An important advantage of dry mixes is the possibility of adding chemical additives and microfillers to them, both improving their structure and prepared for use in the cold season.
Concrete mix transportation technology
Concrete transport includes delivering it from the place of preparation to the construction site, supplying the mixture directly to the place of laying, or reloading it onto other vehicles or devices, with the help of which the mixture is delivered to the concreting unit. A concreting block is a structure prepared for laying a concrete mixture or a part of it with installed formwork and mounted reinforcement.
In practice, the process of delivering concrete mixture to concreting blocks is carried out according to two schemes:
From the place of preparation to direct unloading into the concreting unit;
From the place of preparation to the place of unloading at the object to be concreted, with the subsequent supply of concrete to the concreting block. This scheme provides for the intermediate unloading of the concrete mixture.
The transportation and laying of the concrete mixture must be carried out by specialized means that ensure the preservation of the specified properties of the concrete mixture.
The transportation of the concrete mixture from the place of preparation to the place of unloading or directly to the concreting block is carried out mainly by road, and transportation from the place of unloading to the concreting block is carried out in buckets by cranes, hoists, conveyors, concrete pavers, vibrating feeders, motor carts, concrete pumps and pneumatic blowers.
The method of transporting the concrete mixture to the place of its laying is chosen depending on the nature of the structure, the total volume of the concrete mixture being laid, the daily requirement, the distance of transportation and the lifting height. With any method of transportation, the mixture must be protected from atmospheric precipitation, freezing, drying, as well as from flowing out of cement laitance.
The permissible duration of transportation depends on the temperature of the mixture at the exit from the mixer: it should not exceed 1 hour at a temperature of 20-30 ° C; 1.5 h - 19-10 ° C; 2 h - 9-5 ° C. Long-term transportation on bad roads leads to delamination. Therefore, in vehicles without stimulating the mixture on the way, it is not recommended to transport over a distance of more than 10 km on good roads and more than 3 km on bad ones.
Choice of vehicles carried out based on the conditions of the object under construction: the amount of concrete work; the term of their production; travel distances; the size of the structure in plan and in height; TEP (performance, travel speed, unit cost of transportation). In addition, it is also necessary to take into account the requirements for preserving the properties of the concrete mixture - preventing disintegration, changes in homogeneity and consistency.
To transport the mixture to the facility, road transport is widely used - general-purpose dump trucks, concrete trucks and concrete mixer trucks (mixers).
Transporting the mixture by dump trucks. Disadvantages: difficulties arise in protecting the mixture from freezing, drying, cement laitance leakage through the cracks in the bodies, the need for manual cleaning of the body.
Transportation of concrete mix by concrete trucks equipped with hermetic trough-shaped tipping bodies. Advantages: the mixture can be transported over a distance of 25-30 km, and without splashing it and flowing out of cement milk.
Transportation of the mixture by truck mixers (mixers). This is the most effective remedy transportation. Concrete mixer trucks are loaded at the factory with dry components and are prepared with concrete on the way or on the construction site. The capacity of concrete mixer trucks for the finished batch is from 3 to 10 m 3. Mixing of components with water usually begins 30-40 minutes before arrival at the site. In concrete mixers (mixers), it is also advantageous to transport ready-made concrete mixtures due to the existing possibility of stimulating them along the way due to the rotation of the drum. Advantages: the range of transportation of dry components of the mixture in concrete mixer trucks is technologically unlimited.
The concrete mixture delivered to the object can be unloaded directly into the structure (when concreting structures located at ground level or shallow) or reloaded into intermediate containers for subsequent delivery to the concreting site.
The mixture is supplied to the structures to be concreted by cranes in fixed or rotary buckets or by belt conveyors (conveyors), concrete pumps and pneumatic blowers (through pipes), link trunks and vibrobots, belt-type concrete pavers. Swivel buckets with a capacity of 0.5 - 8 m 3 are loaded directly from dump trucks or concrete trucks. Belt movable conveyors used when it is difficult or impossible to deliver the mixture to the place of laying by means of delivery or in buckets. Conveyors up to 15 m in length serve the mixture to a height of 5.5 m. To reduce the height of the free fall of the mixture during unloading, guide flaps or funnels are used. Disadvantage: conveyors must be rearranged frequently during concreting.
Therefore, self-propelled tape concrete pavers mounted on the basis of a tractor, equipped with a skip hoist and a belt conveyor up to 20 m long. concrete pumps... They supply the mixture through a steel detachable pipeline (concrete pipeline) at a distance of up to 300 m horizontally and up to 50 m vertically. pneumatic blowers... The maximum distance of transportation by them is 200 m horizontally or up to 35 m vertically when feeding up to 20 m 3 / h. For supply and distribution of the mixture directly at the place of laying at a height of 2 - 10 m, use trunks, representing a pipeline of conical metal links and an upper funnel; vibrobots, representing a link trunk with a vibrator. On the loading funnel with a capacity of 1.6 m 3 and sections of the vibrosobot with a diameter of 350 mm, vibrators-stimulators, as well as dampers, are installed every 4-8 m.
The supply and distribution of the concrete mixture in the structure at a distance of up to 20 m with a slope to the horizon of 5-20 ° is ensured vibrating grooves in combination with vibrating feeder with a capacity of 1.6 m 3. They can lay mixtures up to 5 m 3 / h at an angle of inclination of 5 °, and at an angle of 15 ° - up to 43 m 3 / h.
I approve:
______________________
______________________
______________________
"____" __________ 200
ROUTING
TECHNOLOGICAL CARD FOR CONCRETE CONSTRUCTIONS
REINFORCEMENT, FORMWORKING AND CONCRETE WORKS
| Page number |
||
| Title page | ||
| General Provisions | ||
| Requirements for concrete and concrete mix | ||
| Technological equipment and equipment | ||
| Preparatory, formwork and reinforcement works | ||
| Concreting | ||
| Curing concrete | ||
| Quality control of work | ||
| Labor protection in the production of work | ||
| Environmental protection | ||
| Bibliography | ||
| Appendix 1. List of engineers and workers who are familiar with the technological map. |
1. General Provisions
1.1. The technological map applies to the performance of formwork, reinforcement and concrete work.
1.2. The technological map is an integral part of the project for the production of work, developed in relation to a specific construction object, and establishes requirements for the features of the organization and production technology of preparatory formwork, reinforcement and concrete works, aimed at ensuring the high quality of the structures being erected.
1.3. The Technological Map outlines the organizational, technical and constructive-technological measures that must be performed to ensure the quality of concrete in its entirety, to gain concrete of the required strength by the time of stripping, as well as to reduce the likelihood of temperature cracks in structures at the stages of holding and stripping concrete.
1.4. The Technological Map provides for preparatory, formwork, reinforcement and concrete work during year-round construction, taking into account the performance of concrete work in winter conditions in greenhouses.
1.5. When developing the Technological map, it was assumed that the concrete mix will be supplied from a concrete plant located at a distance at which during transportation there will be no loss of mobility below the established value of the workability of concrete, which are given in this technological map.
1.6. When developing the "Technological map", it was assumed that the concreting of grillages, racks and headings of supports is carried out in a metal collapsible formwork.
1.7. Fulfillment of the requirements of the regulations guarantees that the concrete will receive the required grades in terms of strength, water resistance, frost resistance and, ultimately, ensure the required quality and durability of structures.
1.8. When developing the "Technological map", it was taken into account that the prevention of cracking in concrete from temperature effects or its significant reduction is achieved only with the correct combination of structural and technological measures for the production of concrete works.
1.9. Constructive activities include:
selection of structural solutions for the structure as a whole and its individual elements, ensuring the resistance of structures to temperature effects, taking into account local climatic conditions;
Minimization of temperature stress concentrators in the design;
The use of reduced grades of concrete, ensuring the minimum consumption of cement;
Reinforcement of concrete, taking into account the likelihood of thermal cracks.
1.10. Technological measures include the measures outlined below in this "Technological Regulation".
1.11. Concrete work must be carried out in accordance with the project, PPR, this "Technological Regulations", with the current technical numbers and rules, including SNiP 3.06.04-91 "Bridges and pipes", SNiP 3.03.01-87 "Bearing and fencing constructions "; SNiP 12-03.2001 "Labor safety in construction" Part 1. General provisions. SNiP 12-04.2002 "Labor safety in construction" Part 2. Construction production... VSN 150-93 "Instructions for increasing the frost resistance of concrete of transport structures", M., 1993; Manual "Quality control of construction of bridges", M., "Nedra", 1994.
1.12. When developing the "Technological map", it was taken into account that all operations in the leading and most of the auxiliary processes are performed using machines and mechanisms, and handicraft- using a power tool.
1.13. Responsibility for the quality of construction work performed concrete structures is borne by the chief engineer, who must ensure the organization of their defect-free implementation in accordance with the PPR, regulatory documents and these "Technological Regulations".
1.14. Concreting and erection of concrete structures are carried out under the supervision of the contractor and in each shift - a shift foreman.
1.15. During the production of concrete work at the construction site, representatives of the construction laboratory must constantly be present, who must monitor the parameters of the concrete mixture, compliance with the rules for placing concrete, the temperature regime of hardening concrete and the temperature of the outside air, as well as the quality of all incoming materials.
1.16. When carrying out concreting work on a construction site, it is necessary to have appropriate laboratory equipment (a standard cone for determining the mobility of a concrete mixture, devices for determining the amount of entrained air in a concrete mixture, thermometers, sets of forms for taking control cubes and other necessary instruments and equipment).
2. Requirements for concrete and concrete mix
2.1. In accordance with the requirements specified in the working drawings, the material composition of the concrete mixture must ensure that the concrete acquires the strength, frost resistance and water resistance indicators established by the project, namely:
Indicators for strength, frost resistance and water resistance are specified according to the working drawings of the project.
A document on the quality of the concrete mixture is issued for each batch of concrete mixture placed in a separate structure. The supplier company bears guarantee obligations for the quality of the concrete mixture supplied to the construction site.
The application for the supply of concrete mix is drawn up by the CONTRACTOR-PERFORMER OF WORKS on the plant's letterhead with the obligatory indication of the consumer of the concrete mix (CONTRACTOR-PROVIDER OF THE WORK), concrete class (B25, B30 ...), the mobility of the concrete mix at the place of laying (P3, P4), frost resistance (F300 ...), water resistance (W6, W8 ...), technical requirements for materials - binders, aggregates and additives. Start time of concrete mix delivery, delivery address, required volume of concrete mix, required number of concrete mixer trucks.
3. Technological equipment and equipment
3.1. The site for the construction of a concrete structure must have the necessary technological equipment and equipment, as well as materials and fixtures (see table 1).
3.2. Regardless of the time of year, due attention should be paid to the complex moisture-and-heat-protective equipment, which should accelerate the hardening of concrete under conditions of aging in the formwork or under a heat-and-moisture protective coating, and at the stage of heating and cooling of concrete, exclude the possibility of temperature cracks.
3.3 Integrated moisture-and-heat protective equipment consists of:
Inventory metal formwork with forming surface;
Moisture and heat protective inventory coatings - to protect the unformulated surfaces of freshly laid concrete from moisture and heat exchange with the environment;
Awning to protect the concrete surface from rain when working in rainy weather;
Enveloping greenhouses-shells with supporting frame and the required number of heat generators (when performing work in the winter season).
3.4. Polymer films (polyethylene, polyvinyl chloride, etc.) with a thickness of at least 100 microns or rubberized fabric can be used as moisture-protective panels of the inventory moisture-and-heat protective coating.
3.5. As heat-shielding materials, panels of geotextiles, dornite, linen or other heat-insulating materials can be used. roll materials.
3.6. In addition to the complex moisture-and-heat-protective technological equipment, the concreting area should be provided with:
A concrete pump capable of continuously supplying concrete mixture with the required mobility to the formwork;
A crane with sufficient boom reach to supply materials during the erection of supports;
Manual vibrators for compacting concrete mix;
Bunker (bucket) for supplying concrete, if necessary;
A set of hand tools for leveling concrete mix;
A set of "carry lamps" for visual control, if necessary, of the quality of reinforcement and formwork, laying and compaction of the concrete mixture;
3.7. Greenhouses should be made of materials that have low airflow (rubberized fabric, polymer films, etc.) and do not become brittle in the cold.
3.8. When installing greenhouses, it is necessary to ensure a tight abutment of the coatings to the base and previously concreted concrete and reinforced concrete elements.
3.9. To reduce the risk of cracking in the zone of contact between hardening concrete and hardened greenhouses, the previously concreted structures must be heated.
3.10. To ensure normal conditions for heat transfer in the greenhouse, there should not be very narrow cavities. The distance between the fencing of the greenhouse and the heated structure must be at least 1.0 ... 1.5 m.
3.11. In greenhouses with a height of more than 4.0 m, the temperature should be controlled at a height of 0.4 m from the floor and near the ceiling. If there is a temperature difference in the height of the greenhouse of more than 5 - 7 ° C, it is necessary to equalize the air temperature with the help of fans, supplying heated air from the upper part of the greenhouse to the lower one.
3.12. When using heat generators on liquid fuel, if necessary, ventilation of the greenhouses should be arranged.
3.13. Heat houses are equipped with liquid fuel heat generators or electric heaters. The number of heat generators should be determined by calculation depending on the outside air temperature, the required air temperature inside the greenhouse, the conditions of heat exchange between the greenhouse and the environment and the constructive solution of the greenhouse enclosures.
3.14. The greenhouse should be equipped with heat generators or electric heaters with adjustable power, which will allow them to subsequently turn them on or off to smoothly regulate the air temperature in the greenhouse.
3.15. The tepus must have a rigid structure that can withstand the own weight of the fences, wind pressure, snowfall, etc.
3.16. The greenhouse must be sufficiently illuminated to ensure normal working conditions when placing concrete and finishing the surface layer of concrete.
3.17. In greenhouses, it is necessary to have a sufficient number of thermal and moisture protective coatings for concrete care.
3.18. The heating of the greenhouses is terminated only if there is an admissible temperature difference between the hardening concrete on the surface of the structure and the air in the greenhouse (the difference is not more than 20 ° C). Heat generators should be switched off sequentially, ensuring a smooth decrease in the air temperature in the greenhouse.
3.19. The hothouse should be disassembled after the concrete on the surface of the grillages has cooled to a temperature not exceeding the outside air temperature by more than 20 ° C.
The estimated outdoor temperature should be taken as the predicted minimum for the next day.
Table 1
| Appointment of equipment or tooling | Equipment or tooling | Description, brand. | Quantity (pcs.) | Notes (edit) |
|
| Concrete supply | Concrete pump | "SHCVING" Lstr = 42 m | |||
| Concrete compaction | Deep vibrator, d = 50 mm, l = 35 cm. | ||||
| Installation work | Crane with a lifting capacity of 16 t | ||||
| Concrete compaction | Platform vibrator | 2800 rpm |
|||
| Leveling and moving concrete | Soviet shovel | ||||
| Smoothing the concrete surface | The rule is wooden |
4. Preparatory, formwork and reinforcement work
4.1. Prior to the commencement of the production of formwork and reinforcement works for the construction of concrete structures, geodetic alignment works should be fully completed with fixing in place of the axes of concrete structures. Particular attention should be paid to carrying out geodetic works when arranging formwork and installing reinforcing cages.
4.2. When carrying out work, special attention should be paid to ensuring the rigidity of the installed formwork and to the inadmissibility of its deformations and separation under the pressure of the column of the laid concrete mixture, as well as to determine the rate of erection of all support elements, taking into account the setting time of the concrete mixture.
4.3. Before starting work on the reinforcement, the base should be cleaned of debris and dirt.
4.4. When preparing concrete foundations and working joints for removing the cement film, surface treatment is carried out with a water and air jet, metal brushes or sandblasting machines.
4.5. Before concreting the structure, it is necessary to manufacture and mount the reinforcing cages and install the formwork in the concreting area and the embedded parts required by the project.
4.6. Reinforcement work is performed in accordance with the working drawings of the reinforcement of the structure.
For reinforcement, reinforcement with a diameter of 32 mm, 22 mm, 20 mm, 16 mm, 14 mm, 12 mm of class AIII is used, reinforcement steel grade 25G2S, reinforcement with a diameter of 10 mm, 8 mm of class AI, steel grade St5 sp. GOST 5781-82.
The order of storage of fittings and angle.
Steel reinforcement is stored in a specially designated area. Reinforcement packages are laid on wooden lining and covered with waterproof material. Rough handling of the reinforcement, its fall from a height, exposure to shock loads, mechanical damage is not allowed.
Inspection.
Reinforcing bars should be checked for defects such as cracks, local thinning, pores, flaking, dents, bends, rust, local or general curvatures, deviations from the specified cutting length of the rolled metal.
The cleanliness of the fittings.
By the time the reinforcement cage is assembled, the reinforcement must be clean, free from traces of dirt, oil, grease, paint, rust, scale and similar materials.
The reinforcement is tied into space frames using a knitting wire D = 1.6 mm. Reinforcement build-up is performed with an overlap using knitting wire, the overlap of the reinforcement rods is at least 30 reinforcement diameters. In one section, no more than 50% of the joints of the rods should be located.
4.7. Prior to the commencement of work on the concreting of structures, the required number of spacer pads, "crackers", should be made to ensure the required thickness of the protective layer and the design position of the reinforcing cages in all sections of the concreted structural elements. The quality of the concrete of the spacers - "crackers" for the design of the protective layer of concrete must not be lower than the quality of the concrete of the structures.
It is allowed to use factory-made plastic spacers - "crackers".
4.8. Distance spacers should be made of fine-grained concrete with the inclusion of screenings for crushing crushed stone. The dimensions and configuration of concrete spacers - "crackers" must correspond to the design of the reinforcing cage and the design values of the concrete cover, to ensure their stable position in the formwork and on the reinforcing bars of the cage.
To exclude the possibility of staining and subsequent destruction of the surface layer of concrete at the locations of the "crackers" gaskets, the outer (supporting) surface of the gasket made of fine-grained concrete, in contact with the formwork, must have a curved outline (radius of curvature 30-50 m).
4.9. During reinforcement work, embedded parts should be installed in accordance with the project.
4.10. The procurement of reinforcing cages (individual items) and embedded parts, their installation and installation in the formwork and other work related to design features reinforcement of concrete elements is performed in accordance with working drawings.
4.11. On the reinforcing bars laid in the formwork of the frame elements, the required number of spacers - "crackers" are attached, reliably ensuring the design location of the reinforcing cage in the formwork and the size of the concrete cover in all sections.
4.12. The reinforcement installed in place with all embedded elements (parts) must be a rigid frame that cannot be disturbed during concreting.
4.13. Plastic or metal tubes should be fixed to the reinforcement cages in the surface layer and in the central zones in order to form wells for measuring the temperature of the concrete during its curing.
4.14. Installation of formwork panels is carried out in accordance with the project. For concreting, we use inventory formwork made in accordance with TU. Completion sections of the formwork are made on site. For additional formwork, a wooden frame is used. It is necessary to ensure a good tightness of mutual abutment of the edges of the formwork panels. If leaks are found that can lead to a leakage of cement mortar during concreting, all found places before applying the lubricant should be reliably sealed by gluing with adhesive tape (construction tape) 30 - 40 mm wide or smeared with sealant. The joints of the shuttering panels are sealed with silicone or other sealants. Formwork panels must be fastened and fixed (with uprights, stops, struts, straps, etc.) in such a way as to create a rigid, geometrically unchangeable structure.
4.15. Before installation, the forming surfaces of the formwork panels should be wiped with burlap soaked in grease or other grease. The grease should be applied with an extremely thin layer, excluding the ingress of grease on the reinforcement during the installation of the formwork panels.
4.16. After an instrumental check of the position of the reinforcement cages, the installed formwork panels, the reinforcement cages and the installed formwork are examined and an act for hidden work is drawn up with the participation of representatives of the Customer, the general contractor and supervision services.
5. Concreting
5.1 Before starting work on concrete placement, prepare the equipment for the delivery of concrete and check its serviceability.
5.2 Before starting the work, the site manager must clarify: the time of delivery of concrete from the plant to the facility, the availability of documentation confirming the compliance of the concrete mix and concrete indicators with the requirements of this "Technological map". The representative of the construction laboratory must check that a standard cone for determining the flow of concrete, thermometers for measuring the temperature of the concrete mix and outside air, a device for determining the amount of entrained air in the concrete mixture and the adequacy of molds for making control cubes from concrete are available at the facility.
5.3 An effective operational link must be established between the concrete plant and the facility under construction, ensuring the delivery of the concrete mixture in full compliance with the requirements of the project and this "Technological map".
5.4 Delivery of concrete mix to the construction site must be carried out by concrete mixer trucks. The number of concrete mixer trucks must be determined based on the conditions of the volume of the concreted structural elements, the intensity of placing the concrete mixture, the distance of its delivery, and the setting time of the concrete. The total time of delivery of the concrete mixture to the construction site, its laying in structural elements should not exceed the time of its setting.
5.5 Descent supply of concrete mixture to the place of laying can be carried out through link, easily assembled disassembled trunks, concrete pipes and the end hose of the concrete pump.
5.6 Before feeding the concrete mixture directly into the body of the structure, the concrete pump must be tested with a test hydraulic pressure, the value of which.
The assigned composition and mobility of the concrete mix must be checked and specified on the basis of trial pumping of the concrete mix.
The inner surfaces of the concrete pipeline before concreting must be moistened and lubricated with lime or cement mortar.
5.7 When performing concrete work, it is necessary to take into account that in cases of interruptions in pumping the mixture from 20 to 60 minutes, it is necessary to pump the concrete mixture through the system every 10 minutes for 10 to 15 seconds. at low operating modes of the concrete pump. At breaks exceeding the specified time, the concrete pipeline must be emptied and rinsed.
5.8 The intensity of concreting should be determined by the construction laboratory, taking into account the properties of the concrete mixture, the distance of delivery of concrete.
5.9 When performing work in winter period time before concreting each element, the base and the upper zone of previously concreted elements should be warmed up to a temperature of at least plus 5 ° C to a depth of at least 0.5 m.
5.10 To prevent the appearance of temperature cracks in structures, the value of the heating temperatures of previously concreted elements is linked to the temperature of the incoming concrete mixture in accordance with Table 1.
Table 1
Note: *) When the average daily ambient temperature is above + 25 ° C, the thickness of the concreted structures is more than or equal to 1 m, the maximum value of the temperature of the placed concrete mixture is limited to + 20 ° C
5.11 Before concreting, cleaned surfaces prepared in accordance with the requirements of clauses 4.5 - 4.6 must be abundantly moistened with water or treated with 2 ... 5% polymer solution "Acryl 100".
5.12 Descent and delivery of the concrete mixture to the place of placement can be carried out through the end hose of the concrete pump.
5.13 The concrete mixture should be poured into the concreted structure in layers of the same thickness of 25-30 cm (but not more than 40 cm), without breaks, with a consistent laying direction in one direction in all layers.
5.14 The thickness of the successively laid horizontal layers is selected based on the actual rate of supply of the concrete mixture for laying, subject to the condition that the break before laying the next layer of concrete mixture in each specific place does not exceed the terms of the loss of mobility of the previously laid mixture in the previous layer up to 1 - 1.5 see slump of a standard cone (within 40 - 50 minutes) depending on the characteristics of the cement and the actual temperature of the concrete mix. An indicator of compliance with this rule is the absence of a deepening in the concrete when slowly removing the tip of the vibrator with a flexible shaft.
5.15 When laying concrete in layers, a leading horizontal section with a length of 1 - 1.5 m should be formed in each layer, the angle of inclination to the horizon of the surface of the concrete mixture before it is compacted should not exceed 30 °.
5.16 The supply, distribution and compaction of the concrete mixture in each layer should be done only "from the bottom up".
5.17 Before compaction of each layer to be laid, the concrete mixture must be evenly distributed over its surface. The height of individual protrusions and depressions above the general level of the concrete mix distribution surface should not exceed 10 cm. The concrete mix should be distributed by a concrete pump. It is prohibited to use vibrators for redistribution and leveling of concrete mix.
5.18 The vibration of the concrete mixture in each layer and at each position of the permutations of the tip of the deep vibrator is carried out until the settling of the concrete mixture stops and the shine of the cement paste appears on the surface.
5.19 When carrying out concreting work, it is necessary to exclude the possibility of delamination of the concrete mixture at the end of each strip of the concrete layer and the inevitable leakage, immerse it in the concrete mixture at a distance of 50 - 70 cm from the edge of the strip. A thorough joint study of the zone remaining at the edge of the strip is carried out after the next dose of the concrete mixture has been laid.
5.20 After placing the concrete mixture in the first layer of the concrete structure, turn off the concrete pump, transfer the concrete pipes to its end surface and distribute the concrete mixture in the second layer. Vibration compaction of the concrete mixture is also carried out with a lag of 1.0 - 1.5 m from the place where the concrete pump is supplied. Vibration should be carried out with the obligatory "entry" of the vibrator into the underlying layer.
In a similar way, the concrete mixture is laid and compacted in subsequent layers. Strictly consistent distribution of the concrete mixture in horizontal layers, excluding the possibility of its stratification during vibration treatment, is the most important factor in ensuring the quality and homogeneity of concrete in the structure.
5.21 After placing and compacting the concrete in the top layer over the entire open surface of the concrete structure, it is necessary to fine-tune and finish it to ensure the design parameters for slopes, evenness and surface quality.
5.22 After the concrete has set (in 1.5 - 2 hours after laying), a moisture-and-heat protective coating must be laid on the open surfaces of the concrete, consisting of a polyethylene film, two layers of dornite and a top layer of polyethylene film.
6. Curing of concrete
6.1 When erecting concrete structures, taking into account the increased requirements for the quality of concrete of the structures being erected, special attention should be paid to the conditions and duration of concrete curing.
6.2 After a period of maximum heating of the concrete, at the stage of temperature decrease, the additional tarpaulin cover of the formwork can be removed.
6.3 Stop heating the greenhouses, remove the thermal insulation from the structure (heat-and-moisture protective covering on top of the grillage), disassemble the greenhouse, formwork is allowed under the restrictions set forth in clause 3.18 and clause 3.19 of this "Technological map".
In this case, the minimum predicted outside air temperature for the next 24 hours should be taken as the design ambient temperature.
6.4 When holding concrete, the predicted strength of concrete should be confirmed by control tests of samples laid under a heat-and-moisture protective coating.
6.5 Temperature measurements of the hardening concrete of the structure in the first three days after concreting are carried out the first day - every 4 hours, then every 8 hours and, without fail - before removing the heat-and-moisture protective coatings and formwork.
7. Quality control of work
7.1. The chief engineer is directly responsible for the quality of work in accordance with the quality management system of construction and installation works.
A laboratory is involved to carry out measurements and tests.
Laboratory technicians are responsible for sampling at the site.
7.2. Quality control of concreting works is carried out in accordance with the quality assurance plan in order to ensure full compliance with the approved project, working drawings and the requirements of this technological map, as well as compliance with building codes and regulations, standards and technical conditions.
7.3. Quality control of work during concreting is carried out:
Particular attention should be paid to production control, which includes:
Incoming inspection of incoming structures, products and materials;
Operational control;
Acceptance control;
Inspection control.
Incoming control of incoming structures, products and materials is carried out by a commission consisting of representatives of the contractor, the general contractor and technical supervision of the customer with the registration of an Act of the established form.
The compliance of materials with the requirements of the project, technical conditions, SNiP, GOST is checked;
7.4. Fittings and embedded parts
Compliance of the received fittings with the data given in the certificates and shipping documents. Reinforcing bars should be checked for defects such as cracks, local thinning, pores, flaking, dents, bends, rust, local or general curvatures, deviations from the specified cutting length of the rolled metal.
Samples are tested if necessary.
7.5. Concrete mix.
At the place of installation, the following are made:
Control of the plasticity of the concrete mix (cone draft) at least 2 times per shift, with the rhythmic delivery of the concrete mix; in case of irregular delivery of concrete mix - plasticity is determined in each concrete mixer;
Measuring the temperature of the concrete mix - in each concrete mixer truck;
Determination of air entrainment - once per shift;
The selection of concrete samples (cubes) for subsequent tests is carried out by the laboratory assistant at the time of unloading the concrete mixture into the concrete pump.
During the work, the following information on concrete is recorded:
Date of concreting of each block, class of concrete, duration of placing the mixture, position of the structure to be concreted.
Details of the concrete mix, including the nature and source of each of the composite materials, the source of the concrete production; the proposed proportions (according to the concrete mix selection map) or the amount of each component per cubic meter of fully compacted concrete and detailed additives.
Daily maximum and minimum air temperature;
Origin of samples and dates of collection, including identification marks.
Test results on selected samples and description of the concreting block represented by samples.
Test reports of control concrete samples with the results of strength tests of samples at the age of 7 and 28 days.
Records should be kept in a form agreed by the customer, constantly updated, and be available for verification by the customer.
To ensure the identity of the concrete hardening mode of the selected samples, and the concrete hardening mode of the structure to be concreted, the samples remain on the concreting block for the time of setting and hardening. After the characteristic "shine" of the cement paste disappears on the finished area of the surface of the concreted structure, control samples - cubes are laid in this area and covered with panels of a moisture-protective coating made of polymer film, heat-protective mats are laid out, and then a second layer of moisture-protective coating (film) is laid. Control samples are stored under the cover until removed, then the samples are stored in a normal storage chamber (temperature 20 ° C ± 2 ° C, humidity 95%).
7.6. Formwork materials.
Formwork materials, plywood, lumber are checked for compliance with certificates and shipping documents, an external examination is carried out to identify visible defects, damage, etc. Unsuitable materials are rejected with the preparation of an Act on the unsuitability of these materials. Rejected material must not be used for formwork.
Materials for the device of the hothouse.
A check is carried out for compliance with certificates and shipping documents, an external examination is carried out to identify visible damage and violations.
Structures, materials and products arriving without accompanying documents are prohibited from being allowed into production !!!
7.8. Operational control is carried out by the contractor.
Operational quality control is carried out in the course of performing the following construction works:
Installation and dismantling of formwork;
Installation of fittings and embedded parts;
Concrete laying;
Curing.
Operational control should ensure the timely identification of defects and the adoption of measures to eliminate and prevent them.
The main documents for operational control are:
Working drawings;
Technological schemes,
These regulations and standard flow charts;
SNiP, GOST;
Quality control schemes;
Execution results operational control should be recorded in the "General work log", as well as in special work logs, including in the "Concrete work log".
For hidden work, draw up acts of the established form.
7.9. Acceptance control;
During acceptance control, the following is performed:
Acceptance of intermediate structures;
Checking the quality of the erected structural elements.
During acceptance control, the Contractor shall submit the following documentation:
Executive drawings with amendments made (if any) and documents on their approval;
Factory technical passports, certificates;
Hidden works survey certificates;
Acts of intermediate acceptance of structures;
Executive geodetic diagrams of the position of structures and formwork;
Work logs;
Results of laboratory tests of concrete for compliance with design requirements;
7.10. Inspection control;
Inspection control is carried out in order to verify the effectiveness of previously performed production control. This control is carried out by specially created commissions.
7.11. Upon acceptance of the installed formwork and its fasteners, the following must be checked:
Compliance with this technological map;
Reliability of formwork fastening;
Correct installation of plugs and embedded parts;
table 2
| Parameter | Limit deviations | |
| 1. Deviation of lines of intersection planes from the vertical or design slope for the entire height of structures for: | ||
| foundations | Measuring, each structural element, work log |
|
| walls and columns supporting monolithic coverings and ceilings | ||
| walls and columns supporting prefabricated beam structures | ||
| walls of buildings and structures erected in sliding formwork, in the absence of intermediate floors | 1/500 of the height of the structure, but not more than 100 mm | Measuring, all walls and lines of their intersection, work log |
| walls of buildings and structures erected in sliding formwork, in the presence of intermediate floors | 1/1000 of the height of the structure, but not more than 50 mm | |
| 2. Deviation of horizontal planes for the entire length of the verified area | Measuring, at least 5 measurements for every 50 - 100 m, work log |
|
| 3. Local unevenness of the concrete surface when checking with a two-meter rail, except for supporting surfaces | ||
| 4. Length or span of elements | Measuring, each element, work log |
|
| 5. Size cross section elements | 6 mm; -3 mm | |
| 6. Marks of surfaces and embedded products that serve as supports for steel or precast reinforced concrete columns and other prefabricated elements | Measuring, each support element, executive scheme |
|
| 7. The slope of the supporting surfaces of foundations when supporting steel columns without grout | The same, every foundation, executive scheme |
|
| 8. Location anchor bolts: | The same, each foundation bolt, executive diagram |
|
| in plan within the contour of the support | ||
| in plan outside the contour of the support | ||
| in height | ||
| 9. The difference in elevation at the junction of two adjacent surfaces | The same, each joint, executive scheme |
Shield formwork
Table 3
| Formwork panels manufacturing | Formwork installation |
|
| Control composition | Dimensions of formwork panels | Internal dimensions, marks, verticality, position of formwork axes |
| Method and means of control | Visual, measuring; steel tape measure | Visual, measuring; theodolite, level, plumb, rail, steel tape measure |
| Mode and scope of control | Every shield | All assembled formwork |
| Person in control of the operation | Master, surveyor |
|
| Geodetic Service |
||
| Place of registration of control results | Certificate of inspection and acceptance of the installed formwork |
The formwork prepared for concreting must be accepted according to the act for hidden work.
7.12. Quality control of reinforcement works consists in checking compliance with the project and standards of products and embedded parts, binding and welding of reinforcement. Replacement of the reinforcing steel envisaged by the project must be agreed with the design organization (field supervision).
Incoming reinforcing steel must be recorded in the Incoming Inspection Log.
During the incoming inspection, all incoming reinforcing steel and embedded parts must be subject to mandatory external inspection and measurements.
Inspection of reinforcement and embedded products must be carried out in compliance with the requirements of Table 4.
Valve control
Table 4
| Parameter | Parameter value, mm | Control (method, volume, type of registration) |
| 1. Deviation in the distance between separately installed working rods for: | Technical inspection of all elements, work log |
|
| columns and beams | ||
| slabs and walls of foundations | ||
| massive structures | ||
| 2. Deviation in the distance between rows of reinforcement for: | ||
| slabs and beams up to 1 m thick | ||
| structures with a thickness of more than 1 m | ||
| 3. The deviation from the design thickness of the concrete cover should not exceed: | ||
| with a protective layer thickness of up to 15 mm and linear dimensions of the cross-section of the structure, mm: | ||
| from 101 to 200 | ||
| with a protective layer thickness from 16 to 20 mm incl. and linear dimensions of the cross-section of structures, mm: | ||
| from 101 to 200 | ||
| from 201 to 300 | ||
| with a protective layer thickness over 20 mm and linear dimensions of the cross-section of structures, mm: | ||
| from 101 to 200 | ||
| from 201 to 300 | ||
All reinforcement installed in the formwork must be taken before concreting; the results of the survey and acceptance should be formalized with an act for hidden work.
The main operations that are subject to control during the production of reinforcement works, control methods and controlled operations are shown in Table 5.
Control methods and controlled elements in the production of reinforcement work
Table 5
| Basic operations to be controlled | Reinforcement blank | Assembling reinforcement meshes |
| Control composition | Cleanliness, quality of reinforcement, bar sizes, steel grade | Weld seams, their dimensions, mesh placement, providing a protective layer, quality |
| Method and means of control | Visual measuring, meter | Visual measuring, steel meter |
| Mode and scope of control | Solid | All grids |
| Person in control | Master, laboratory assistant |
|
| Person in charge of organizing and exercising control | ||
| Services involved for control | Laboratory |
|
| Control Results Registration Wizard | General works journal. Welding log |
7.13. The technological requirements that must be observed during the production of concrete works and checked during operational control, as well as the scope, methods or methods of control, are given in Table 6.
Concrete work.
Table 6
| Technical requirements | Control | Method or method of control |
| 1. At the place of laying, the mobility of the concrete mixture should be in the range of 10 - 15 cm for structural elements | At least twice a shift with rhythmic mass concrete placement, the rest of the concrete mixer trucks are visual. | Check in accordance with GOST 10181.1-81 with registration in the journal of concrete work, concrete care, the Certificate of production of control samples, the journal of the arrival of the concrete mixture. |
| 2. The temperature of the concrete mixture at the place of laying should not differ from the regulated by more than ± 2 ° C (from 5 to 25 °) | In every concrete mixer on the construction site | Registration, measuring |
| 3. The thickness of the concrete layer to be laid should not exceed 40 cm. | Permanent during concrete placement | Measuring, visual |
| 4. The volume of air entrained in the concrete mix - from 3 to 5% for concrete with a frost resistance grade F 200 | Once per shift (with constant: composition of concrete, quality of materials, modes of preparation of concrete mixture) | Check in accordance with GOST 10181.3-81 |
| 5. Norms of samples for concreting structures | For each structural element of monolithic concrete structures, at least one series per shift. | See GOST 18105-86 |
| 6. The number of series of samples made from one sample of concrete mix at the facility | According to paragraph 2.3 of GOST 18105-86 | Registration |
| 7. Acceptance of structures for water tightness and frost resistance is carried out on the basis of the requirements of the project documentation | According to the acts of the supplying plant, the results of determining the frost resistance of concrete laid in the structure. | According to the quality document in accordance with GOST 7473-94, clauses 4.1 - 5.2 with the attachment of the factory test certificate in accordance with GOST 10060-95 and GOST 12730.5-84 |
7.14. Forms with samples for determining the strength of concrete at the age of 28 days immediately after production must be installed in places of the lowest temperatures and in contact with the concrete surface for each structural element.
Before installation, molds with freshly formed samples must be wrapped in foil and placed under a heat-shielding coating.
Sample forms must be stored under a moisture-proof coating until testing. After removing the moisture-and-heat protective coating from the structure, the remaining control samples (which have gained at least 70% of strength) are unfolded and stored until the required tests under normal conditions in accordance with GOST 10180-90.
8. Labor protection in the production of work
Labor protection is carried out in accordance with the health and safety plan (in accordance with SNiP 12-03-2001, SNiP 12-4-2002, PB 10-382-00).
8.1. General requirements
TO independent work a concrete worker is allowed to persons who have reached 18 years of age, recognized as fit for this work by the medical commission, trained in safe methods and techniques of work and instructions on labor safety and having a certificate for the right to work as a concrete worker.
A concrete worker who starts work must undergo an introductory briefing on occupational safety, industrial sanitation, first aid, fire safety, environmental requirements, working conditions, initial instruction at the workplace, which must be recorded in the appropriate logs with the obligatory signature of the instructed and instructor. Re-instruction is carried out at least once every 3 months. Unscheduled briefings are carried out when new or revised standards or other regulatory documents on labor protection are introduced, when the technological process changes, equipment and tools are replaced or modernized, materials are replaced, when workers violate labor safety requirements, at the request of the supervisory authorities, during work interruptions for more than 30 calendar days. Targeted briefing is carried out when performing one-time work.
Before starting work, workplaces and passages to them must be cleared of foreign objects, debris, dirt, and in winter - from snow and ice and sprinkled with sand.
It is forbidden to stay in the danger zone of the lifting mechanisms, as well as stand under the raised load.
Machines, power tools and lighting lamps can only be switched on using circuit breakers. Avoid the presence of poorly insulated electrical wires that are not fenced on the site electrical devices... When working with a power tool, a concrete worker must be trained and have I qualification group for safety.
Before starting the equipment, check that the guards are secure in all exposed rotating and moving parts.
If a malfunction is detected in the mechanisms and tools with which the concrete worker works, as well as fences, it is necessary to stop work and immediately inform the foreman about it.
Upon receipt of the instrument, one must make sure that it is in good working order; the defective instrument must be returned for repair.
When working with hand tools (scrapers, bush hammers, shovels, rammers), it is necessary to monitor the serviceability of the handles, the tightness of the tool attachment on them, and also to ensure that the working surfaces of the tool are not knocked down, dull, etc.
The electrified tool, as well as the electrical wire supplying it, must have reliable insulation. Upon receipt of the power tool, the condition of the wire insulation should be checked by external inspection. When working with the tool, make sure that the power cable is not damaged.
8.2. Requirements before starting and during work
When starting work, the concrete worker should put on the overalls provided for by the norms, while the hair should be removed under the headdress, buttoned up the cuffs of the sleeves or tightened with an elastic band.
When placing concrete mixture with a concrete pump, it is necessary to check the operation of two-way signaling (sound, light) between the driver of the concrete pump and the workers receiving the concrete. Clean and tightly lock all pipe fittings. Do not take the concrete mixture with a faulty concrete pump. The driver of the concrete pump before starting must give a warning signal and start up the concrete pump for testing at idle speed for 2 - 3 minutes.
When delivering concrete in a concrete mixer truck, the following rules must be observed:
When unloading a concrete pump into the hopper, you must first put the mixer truck on the handbrake and give a sound signal;
At the moment the mixer truck approaches, all workers must be on the side of the driveway opposite to the one on which the movement is taking place;
It is forbidden to approach the concrete mixer until it comes to a complete stop.
Before starting placing the concrete mixture in the formwork, it is necessary to check:
Fastening of formwork, supporting scaffolding and working platforms;
Fastening to the supports of loading funnels, trays and trunks for lowering the concrete mixture into the structure, as well as the reliability of fastening individual links of metal trunks to each other;
Condition of protective covers or flooring around the hoppers.
Concrete workers working with vibrators are required to undergo a medical examination every 6 months.
Women are not allowed to work with a hand-held vibrator.
Concrete workers working with electrified tools must know the measures of protection against electric shock and be able to provide first aid to the victim.
Before starting work, you must carefully check the serviceability of the vibrator and make sure that:
The hose is well attached, and if it is accidentally pulled, the ends of the winding will not break;
The lead-in cable has no breaks or bare spots;
The grounding contact is intact;
The switch is working properly;
The casing tightness bolts are well tightened;
The joints of the vibrator parts are sufficiently tight, and the motor winding is well protected from moisture ingress;
The shock absorber on the vibrator handle is in good condition and adjusted so that the vibration amplitude of the handle does not exceed the standards for this tool.
Before starting work, the body of the electric vibrator must be grounded. The general serviceability of the electric vibrator is checked by testing it in a suspended state for 1 minute, while the tip should not be resting on a solid base.
To power the electric vibrators (from the switchboard), use four-core hose wires or wires enclosed in a rubber tube; the fourth core is necessary for grounding the vibrator body, operating at a voltage of 127 V or 220 V.
You can turn on the electric vibrator only with a switch protected by a casing or placed in a box. If the box is metal, it must be grounded.
Hose wires must be suspended and not routed over the laid concrete.
Do not pull the vibrator by the hose cord or cable while moving it.
In the event of a break in live wires, arcing of contacts and a malfunction of the electric vibrator, stop working and immediately inform the master about it.
Working with vibrators on ladders, as well as on unstable scaffolds, decks, formwork, etc. is prohibited.
When working with electric vibrators operating from a network with a voltage of up to 220 V and above, it is necessary to wear rubber dielectric gloves and boots.
During continuous operation, the vibrator must be turned off for five minutes every half hour to cool down.
When it rains, the vibrators should be covered with tarpaulins or stored indoors.
During breaks in work, as well as when concrete workers pass from one place to another, the vibrators must be turned off.
The concrete worker working with the vibrator must not allow water to fall on the vibrator.
8.3. Safety precautions when working at height.
All work should be performed in accordance with SNiP 12-03-2001 "Labor safety in construction" part 1, "Labor safety in construction" part 2.
Workplaces and passages to them at a height of 1.3 m or more, and at a distance of less than 2 m from the border of the height difference, are fenced with temporary inventory fences in accordance with GOST 12.4.059-89. If it is impossible to use safety barriers or in the case of a short period of time when workers are at a height, it is allowed to carry out work using a safety belt.
Scaffolds are equipped with ladders or ladders for lifting and lowering people in the amount of at least two.
Ladders and ladders are equipped with a device that prevents the possibility of shifting and overturning them during operation.
The workers involved in the assembly and dismantling of scaffolds must be instructed on the methods and sequence of work and safety measures.
Metal scaffolding is not allowed to be installed closer than 5 m from the masts of the electrical network and operating equipment. Electric wires located closer than 5 m from the scaffolding must be de-energized and grounded, or enclosed in boxes, or dismantled during their installation or disassembly. The scaffold must be grounded.
Access for unauthorized persons (not directly involved in these works) in the area where the scaffolds are installed or dismantled must be closed.
At the time of work at a height, the passage under the place of work must be closed, and the danger zone must be fenced off and marked with safety signs. Scaffolds should not be used to store materials.
Only those materials that are directly used (processed) are fed to the scaffold.
9. Environmental protection
9.1. THE CONTRACTOR-PERFORMER OF WORKS, must keep the construction site clean and provide appropriate facilities for the temporary storage of all types of waste until they are removed. Construction waste is stored only in specially designated places indicated on the construction site plan.
THE CONTRACTOR-PERFORMER OF THE WORKS is responsible for ensuring the safe transportation and disposal of all types of waste in such a way that it does not lead to environmental pollution or damage to human or animal health.
All sites and buildings are kept clean and tidy. All working personnel were instructed against signature, entered in the appropriate log and informed about the requirements for the maintenance of the workplace and the responsibility of each for order at his place of work and rest.
Waste disposal should include the following:
Separate containers for different types of waste (metals, food waste, hazardous materials, garbage, etc.) with tightly closed lids;
Places of installation of containers;
Spent scrap metal is temporarily stored at designated landfills, agreed with the Committee for Environmental Protection, the Land Committee, local authorities;
Waste concrete is temporarily stored at temporary waste storage sites in specially equipped areas with improved coverage. Waste reinforced concrete structures will be removed by special vehicles for placement at the landfill;
Washing of truck-mounted concrete mixers and truck-mounted concrete pumps should be carried out only in the places indicated by the General Contractor.
Lump wood waste, unsuitable for use on the site, is temporarily stored at the temporary storage site and will be removed by motor transport for placement at the landfill;
Household waste will be removed by special vehicles for disposal and processing at the landfill in accordance with a waste disposal agreement with a specialized enterprise.
All waste hazardous to health undergoes final disposal at the appropriate enterprises or landfills, agreed with the local administration and regulatory authorities, under contracts, copies of which will be provided to the Customer.
Refueling of construction equipment in the process of work is carried out by certified fuel tankers "from wheels". All oils and lubricants are stored in warehouses in hermetically sealed containers with clear marking in Russian. When fuels and lubricants get on the soil or concrete surface, measures are immediately taken to cut and dispose of contaminated soil, from the concrete surface fuels and lubricants are removed with sand or with the help of sawdust with subsequent disposal.
9.2. Protection of flora, fauna and habitat.
The planned activity sets the goal of minimal and temporary alienation of land, disturbance of vegetation cover.
In order to minimize the negative impact on the animal and vegetable world, during the construction period of the facility, the CONTRACTOR-PERFORMER OF WORKS must be performed organizational and technical measures:
Providing the facility with individual, passive and active fire-fighting equipment, strict control of compliance with fire safety rules;
Preservation of the soil cover by maintaining equipment in good condition, excluding the spill of oil products on the soil;
Operation of equipment only within the boundaries of the construction site allotment using the existing access roads;
During the construction period, the protection of the animal world, first of all, will consist in observing environmental legislation, minimizing the impact on the atmospheric air, surface waters, which will indirectly reduce the degree of the facility's impact on the environment.
9.3. Minimization of air pollution and noise pollution of the environment.
Reducing the dustiness of the air that occurs during construction is achieved through the following:
The use of crushed stone roads, both on the construction site and between the construction site and the village for construction workers, as well as inside the village;
Regular road cleaning and wetting to prevent dustiness in the air.
To reduce possible negative impacts on the atmospheric air during construction, the CONTRACTOR-PERFORMER of WORKS should use only serviceable construction equipment with regulated fuel equipment, which ensures the minimum possible emission of pollutants into the environment, including effective silencers;
Operates and maintains equipment in accordance with the manufacturer's instructions and instructions, with special attention controlling noise and emission of pollutants;
Provides constant monitoring of compliance with the current operating rules;
The equipment used for construction is subject to regular maintenance and checking for possible malfunctions;
Incineration of production waste is not allowed;
It is prohibited to use ozone-depleting agents and freons in cooling and fire extinguishing systems;
In the summer period of construction, to reduce dustiness on access or working roads, the surface of the road bed should be constantly watered with water sprinklers.
9.4. Plan CONTRACTOR-PERFORMER OF WORKS for the organization of work on the collection, storage and disposal of waste
During the production of work at the facility, 2 types of waste are generated:
Production ( construction garbage);
Household waste.
When handling hazardous waste, an appropriate act is drawn up based on the results of bringing the products into a safe state, which is approved by the head of the enterprise - the owner of the product.
In the process of collecting and accumulating waste, they are identified with the definition of belonging to a certain type of waste; for each type of waste there are separate closed-type containers (metals, food waste, hazardous materials, garbage, etc.), marked with warning signs.
THE CONTRACTOR-PERFORMER OF WORKS develops measures to minimize the amount of generated waste:
Use of equipment and spare parts for the full stipulated period of their operation;
Using waste as raw material in a new technological cycle;
Shift supervisors are responsible for compliance with environmental protection requirements.
Bibliography
| GOST 2379-85 | ||
| GOST 7473-85 * | Concrete mixes. Technical conditions |
|
| GOST 8267-93 | Crushed stone and gravel from dense mining for construction work. Technical conditions. |
|
| GOST 8478-81 | ||
| GOST 10060.0-95 | Methods for determining frost resistance. Concrete. General requirements |
|
| GOST 10178-95 | Portland cement and slag portland cement. Technical conditions |
|
| GOST 10180-90 | Concrete. Methods for determining the strength of control samples |
|
| GOST 10181.1-81 | ||
| GOST 10181-2000 | Concrete mixes. Test methods |
|
| GOST 10922-90 | Reinforcing and embedded products welded joints Reinforcing welded and embedded products of reinforced concrete structures. General technical conditions. reinforcement and embedded products |
|
| GOST 12730.5-84 | Concrete. Methods for determining water resistance |
|
| GOST 14098-91 | Welded reinforcement joints and embedded products of reinforced concrete structures. Types, designs and sizes. |
|
| GOST 18105-86 * | Concrete. Strength control rules |
|
| GOST 18242-72 * | Statistical acceptance control on an alternative basis. Control plans. |
|
| GOST 23732-79 | Water for concrete and mortars. Technical conditions. |
|
| GOST 24211-91 | ||
| GOST 25346-89 | ESDP. General provisions, series of tolerances and basic deviations 7.16 |
|
| GOST 25347-82 * | ||
| GOST 26633-91 | Concrete is heavy and fine-grained. Technical conditions. |
|
| SNiP 2.05.03-84 * | Bridges and pipes |
|
| SNiP 3.03.01-87 | Bearing and enclosing structures |
|
| SNiP 3.06.04-91 | Bridges and pipes |
Annex 1
snipov.net
VET
TECHNOLOGICAL CARD NO.
1 Scope .. 3
2 organization and technology of work .. 3
3 REQUIREMENTS FOR QUALITY AND ACCEPTANCE OF WORKS .. 4
4 LABOR PROTECTION AND INDUSTRIAL SAFETY .. 5
5 ENVIRONMENTAL PROTECTION ... 6
6 LIST OF REGULATORY-TECHNICAL AND REFERENCE DOCUMENTS .. 7
6 Familiarization sheet ... 8
The technological map provides for the organization and technology of concrete work
The work under consideration includes:
- preparation of concrete mix;
- reinforcement work;
- laying concrete;
- control methods.
- organization and technology of work
When performing work, the requirements of the regulatory documents given in section 6 should be followed.
Raw materials and materials used in the manufacture of monolithic foundations must comply with the current regulatory and technical documentation, be accompanied by documents of supplier enterprises, certifying their quality.
The design of a monolithic foundation must meet the requirements of existing regulatory documents.
Preparation of concrete mix.
The concrete mix is prepared in a forced-action concrete mixer.
The choice of cements for the preparation of concrete mixtures should be made in accordance with GOST 30515-97. Acceptance of cements should be carried out in accordance with GOST 30515-97, transportation and storage of cements - in accordance with GOST 30515-97 and SNiP 3.09.01-85.
Aggregates for concrete are used fractionated and washed. It is forbidden to use a natural mixture of sand and gravel without sieving into fractions.
Dosing of the components of concrete mixtures should be carried out by weight. Dosing by volume of water of additives introduced into the concrete mixture in the form of aqueous solutions is allowed. The ratio of components is determined for each batch of cement and aggregates, when preparing concrete of the required strength and mobility. The dosage of the components should be adjusted during the preparation of the concrete mixture, taking into account the data from the control of indicators of the properties of cement, moisture, granulometry of aggregates and control of strength.
When preparing a concrete mixture using separate technology, the following procedure must be observed:
- water, part of sand, finely ground mineral filler (if used) and cement are dosed into a working high-speed mixer, where everything is mixed;
- the resulting mixture is fed into a concrete mixer, pre-loaded with the remainder of the aggregates and water, and everything is mixed again.
- the break between the stages of concreting (or laying layers of concrete mixture) should be at least 40 minutes, but not more than 2 hours.
- the use of additives (antifreeze, air-entraining, concrete hardening accelerators and retarders, etc.) is permitted.
Reinforcement work.
Reinforcement work should be performed in accordance with the technological map P
Laying and compaction of concrete mixes
The concrete mix should be laid by concrete pavers equipped with devices that dispense and distribute the mix in the limiting boarding equipment, as a rule, without the use of manual labor.
When laying concrete mixes in an open landfill, it is necessary to take measures (special shelters, sheds, film coatings) to protect concrete mixes and freshly formed products from the harmful effects of atmospheric influences.
Forming modes must ensure the coefficient of compaction of the concrete mixture (the ratio of its actual density to the calculated theoretical): for heavy concrete - not less than 0.98; when using hard mixtures and appropriate justification, as well as for fine-grained concrete - not less than 0.96. The volume of intergranular voids in the compacted lightweight concrete mixture must comply with the requirements of GOST 25820-83.
Deforming of products after heat treatment should be carried out after the concrete has reached its stripping strength.
Quality control of work should be carried out in accordance with the requirements of the regulatory documents given in section 6:
When accepting finished concrete and reinforced concrete structures or parts of structures, the following should be checked:
- compliance of structures with working drawings;
- the quality of concrete in terms of strength, and, if necessary, frost resistance, water resistance and other indicators specified in the project;
- the quality of materials used in the construction, semi-finished products and products.
Acceptance of finished concrete and reinforced concrete structures or parts of structures should be formalized in the prescribed manner by an act of survey of hidden works or an act of acceptance of critical structures.
Scope of operations and control means during concreting
download TECHNOLOGICAL CARD for Concrete works
Leading employees and specialists of the organization, according to the list of positions approved by the head of the organization, before being admitted to work, and then periodically within the established timeframe, are tested for their knowledge of occupational health and safety rules, taking into account their job responsibilities and the nature of the work performed. The order of training and knowledge testing is established in accordance with GOST 12.0.004-90 SSBT “Organization of occupational safety training. General Provisions "and in accordance with the Decree of the Ministry of Labor of the Russian Federation of 13.01.2003. "The order of training on labor protection and testing the knowledge of labor requirements of employees of organizations." Approximate position on the procedure for training and testing knowledge on labor protection of executives and specialists of organizations, enterprises and institutions and institutions of construction, the building materials industry and housing and communal services.
Workers performing work must undergo a knowledge test and have a certificate of knowledge testing on labor protection with them.
Employees who have not previously been trained in safe working methods by profession, within a month from the date of enrollment in work, must be trained in accordance with GOST 12.0.004-90 SSBT in the amount of instructions for labor protection for the relevant professions, drawn up on the basis of industry instructions on labor protection, and get a certificate of labor protection.
Workplaces should be provided with first aid kits with medications.
List of documents that must be located at the place of work:
- Orders on the appointment of responsible persons for labor protection, industrial safety;
- Orders on the appointment of persons responsible for the good condition and safe operation of machines, mechanisms;
- Orders for fixing equipment;
- workplace briefing log;
- journal of comments and suggestions;
- incoming control log.
In order to protect the environment, when carrying out the above work, it is prohibited:
- violate the boundaries of the territories allocated for construction;
- to pollute the environment with construction waste, for which it is necessary at the design stage to provide for methods of processing and disposal of waste;
- disrupt the natural drainage network;
- passage of equipment and transport in places not provided for by the project for the production of work;
- plan and cut steep slopes at sites due to the potential for soil erosion;
- not comply with the requirements of local environmental authorities.
For damage to the environment (destruction of soil and vegetation cover, pollution of water bodies, allowing fires in forests, peatlands, etc.) outside the right-of-way, the work managers, as well as workers, directly damaging the environment.
- LIST OF REGULATORY-TECHNICAL AND REFERENCE DOCUMENTS
- SNiP III-42-80 *. Trunk pipelines;
- - SNiP 3.02.01-87. Earthworks, foundations and foundations;
- SNiP 3.03.01-87. Bearing and enclosing structures;
- VSN 004-88. Construction of main pipelines. Technology and Organization;
- VSN 014-89. Construction of main and field pipelines. Environmental protection;
- GOST R 51285-99. Twisted wire meshes with hexagonal cells for gabion structures. Technical conditions;
- GOST 7502-98. Metal measuring tape. Technical requirements.
- GOST 12-03-01. SSBT. Personal respiratory protection. Classification and labeling;
- GOST 12.3.003-86 *. SSBT. Electric welding works. Safety requirements;
- GOST 123.016-87. SSBT. Construction. Anticorrosive works. Safety requirements;
- SNiP 12-03-2001. Labor safety in construction. Part 1. General requirements;
- SNiP 12-04-2002. Labor safety in construction. Part 2. Construction production;
- SP 12-136-2002. Occupational health and safety solutions in construction management projects and work production projects
- POT R M-016-2001. Interindustry rules on labor protection (safety rules) during the operation of electrical installations;
- PB 10-382-00. Rules for the construction and safe operation of cranes;
- Rules for the technical operation of consumers' electrical installations ";
- POT R M-027-2003. Cross-sectoral rules on labor protection in road transport;
- Safety rules for the operation of main oil pipelines.
| Item No. | Full name | Employee position | date | Signature |
| 1. | ||||
| 2. | ||||
| 3. | ||||
| 4. | ||||
| 5. | ||||
| 6. | ||||
| 7. | ||||
| 8. | ||||
| 9. | ||||
| 10. | ||||
| 11. | ||||
| 12. | ||||
| 13. | ||||
| 14. | ||||
| 15. | ||||
| 16. | ||||
| 17. | ||||
| 18. | ||||
| 19. | ||||
| 20. | ||||
| 21. | ||||
| 22. |
otdel-pto.ru
General instructions
These guidelines are intended for students in the direction of training 270800.62 "Construction" and is intended to assist in the implementation of term papers and diplomas in the section "Technology and organization of construction production"
Technological maps are one of the main documents of the project for the production of work, containing a set of guidelines for the rational organization and technology of construction production, which contribute to increasing labor productivity, improving quality and reducing the cost of construction and installation work.
Flow charts are mandatory for use by work manufacturers, foremen and foremen as a guide to organizing production and labor of workers when performing construction and installation work at a specific facility.
The instruction contains a general methodology and sequence for the development of technological maps, examples of the implementation of technological maps for the following construction processes are given:
Excavation;
Concrete works;
Installation work;
Stone works;
Pile work;
Backfilling and soil compaction.
Flow charts that are part of a work production project are usually developed for complex types of work and work performed by new methods. The main purpose of these cards is to assist builders and designers in the development of technological documentation.
The technological sequence of construction processes is established according to the flow charts, weekly and daily schedules and work orders are drawn up. They are used both when performing construction and installation works, and when justifying the duration of the construction of facilities in the calendar plans and network schedules of work production projects.
The use of technological maps, including standard ones, helps to improve the organization of production, increase labor productivity and its scientific organization, reduce costs, improve quality and reduce the duration of construction, safe work performance, organization of rhythmic work, rational use of labor resources and machines, as well as reduction of the terms of preparation of PPR and unification of technological solutions.
Technological maps (TC) are developed for the implementation of construction and installation and special construction processes, the products of which are complete structural elements of a building or structure, technological equipment, pipelines and their units, as well as for production certain types works - earthen, roofing, painting, anticorrosive, heat-insulating, etc. In some cases, technological maps are developed for complex construction and installation work (for laying 100 m of pipeline, collector, 1 km of electric cable, etc.). Technological maps must be developed and referenced previously developed (standard) with the obligatory consideration of the real conditions of construction - the accepted organization of work, a specific set of existing construction machines, mechanisms, devices, vehicles, as well as climatic and other conditions. At the same time, one should focus on advanced equipment and construction technology.
For the development of TC, as initial data and documents, you need: working drawings, building codes and rules (SNiP), instructions, standards, factory instructions and technical conditions for installation, start-up and adjustment of equipment, equipment passports, uniform norms and prices for construction and installation work (ENiR), local progressive norms and rates, labor organization and labor processes.
Standard technological maps (TTC) are developed in order to ensure the construction of standard and repetitive buildings, structures and their parts with rational solutions for the organization and technology of construction production, which contribute to increasing labor productivity, improving quality and reducing the cost of construction and installation work. TTK are intended for use by organizations developing projects for the production of work for the construction of new or reconstruction and expansion of existing structures.
The TTK is developed according to the working drawings of standard and reusable buildings and structures on the basis of the study and generalization of best practices, taking into account: technological processes ensuring the required level of work quality; complex supply of structures, products, semi-finished products and materials; maximum use of the front of work and the combination of construction processes; the introduction of comprehensive mechanization with the maximum use of machines in two or more shifts, as well as the use of small mechanization means; delivery of structures and technological equipment enlarged blocks; compliance with the rules of industrial sanitation, labor protection and safety measures. The organizational and technological solutions adopted by the TTK must ensure high technical and economic indicators, the quality and safety of work in accordance with the requirements of the current norms and rules of construction production.
The composition of the technological map
The technological map should contain the following sections:
Here are:
characteristics of the building, structural elements and their parts or parts of buildings and structures (indicating standard projects, main parameters and schemes);
nomenclature of types of work covered by the card;
characteristics of the conditions and features of the production of work adopted in the map;
instructions on linking the map to a specific object and construction conditions.
II. Organization and technology of the construction process. This section contains:
instructions for the preparation of the object and the requirements for the readiness of previous work and building structures, which provide the necessary and sufficient scope of work to complete the construction process provided for by the map;
plan and sections of that structural part of a building or structure, on which the work provided for by the technological map will be carried out, as well as the construction site organization diagrams ( working area) during the production period of this type of work (plans, sections and diagrams must indicate all the main dimensions and placement of units, machines, loading and unloading devices, warehouses of basic materials, semi-finished products, products, roads);
instructions on the duration of storage and stock of structures, products and materials at the construction site (working area);
methods and sequence of work, breakdown of a building (structure) into grabs and tiers, methods of transporting materials and structures to workplaces, types of scaffolds, devices, mounting equipment used;
the numerical and qualification composition of the brigades and units of workers, taking into account the combination of professions;
work schedule and calculation of labor costs;
instructions for linking maps of labor processes in construction production, providing for the rational organization, methods and techniques of workers' labor to perform individual operations included in the construction process, provided for by the technological map;
instructions for monitoring and assessing the quality of work in accordance with the requirements of the SNiP chapters for the production and acceptance of work and a list of required certificates of inspection of hidden works;
solutions for labor protection and safety in the performance of work requiring design development.
Technological maps for work performed in the winter should additionally contain instructions on the mode of maintaining structures, places for measuring temperature and humidity, methods of insulating and sealing joints in structures, schemes for performing work in winter.
III. Technical and economic indicators. This section provides:
1. Labor costs for the entire scope of work, man-days.
Labor costs for the entire volume of work are determined by calculating labor costs as the sum of the rows in column 8 (see table 1.1)
2. Costs of machine shifts for the entire scope of work.
The total demand for machines is determined by the calculation of labor costs as the sum of column 9 (see table 1.1).
3. Labor costs for the adopted unit of measurement, man-h. (person-days).
It is calculated by dividing the amount of labor costs (labor intensity) by the physical amount of work.
4. Production per worker per shift in physical terms;
Production is calculated either by dividing the cost of construction and installation work to be performed by the labor intensity of their implementation, and then the indicator has a monetary expression (rubles / person-day), or by dividing the physical volume of work by labor intensity, and then the production is obtained in kind expression (1 m2 of area, 1 m3 of structure, 1 m3 of a building for 1 person-day or for 1 person-hour, etc.).
5. Duration of work execution in days. The duration of the work in days is determined according to the work schedule (column 15, table 1.5).
IV. Material and technical resources. This section provides the resource requirement for the construction process envisaged by the map, determined by working drawings, specifications or by the physical volume of work and resource consumption rates. The number and types of machines, tools, inventory and accessories are determined according to the work organization scheme adopted in the map in accordance with the amount of work, the timing of their implementation and the number of workers. The need for operating materials is determined in accordance with the rates of their consumption.
Making a technological map
The text of the map is drawn up in the form of an explanatory note on A4 sheets, the pages must be numbered. Sections should be numbered with Arabic numerals within the entire technological map. Within the sections, the text is subdivided into paragraphs, which are numbered in Arabic numerals within each section. The item number must consist of the section and item numbers, separated by dots.
The calculation of labor costs is carried out in the form of table 1.1.
Table 2.1. Calculation of labor costs
The list of works (column 2) is filled in in the technological sequence of the work.
The scope of work (columns 3, 4) is determined by working drawings and estimates. The sampling of volumes from estimates is less laborious, but since the estimates do not contain division of volumes by captures, to clarify the volumes individual works use directly working drawings and specifications to them, controlling the correctness of calculations for estimates. The volume of work should be expressed in units adopted for calculating the labor intensity and machine intensity.
Justification. In gr. 5 indicates the justification (paragraph number, table, columns and positions of the norm adopted by ENiR, HPES or others).
The time rate per unit of measurement (columns 6, 7) are filled in according to the accepted justification.
The calculations in the calculation of labor costs (KTZ) can be based on data of varying degrees of objectivity, the adequacy of which to real conditions is not the same.
The purpose of calculating labor costs and machine intensity in KTZ is to determine the need for these resources. But in the presence of reliable data of experience, labor intensity and machine intensity should be taken according to the actually achieved at a similar facility. In this case, the data on the composition of the brigade, labor costs and other parameters are simultaneously known.
Thus, the greatest accuracy is ensured by the use of information on the achieved productivity of a given brigade at a similar facility (for example, a house of the same series). Less accurate are the calculations, which are based on the development of the same brigade at a close constructive solutions facility or another team of the same organization at a similar facility.
Calculations based on estimated norms, ENiR, etc. are less accurate, since they do not take into account a number various factors, which can be grouped into the following groups:
the influence of climatic and seasonal conditions of work;
specific solutions for the mechanization of work, averaged in the standards of labor costs;
the way of doing work and the level of organization of production and the labor productivity achieved by this team.
The complexity of the work (columns 8, 9) and the costs of computer time are determined by the following formulas:
where 8 hours is the duration of the shift.
The composition of the link (column 10) is adopted according to the accepted justification without change.
At the end of the KTZ, the results are put down for columns 8 and 9.
The operational quality control scheme is carried out in the form of a table.
Table 2.2. Operational quality control
The name of the operations (columns 2, 3) subject to control are filled in in the technological sequence of their execution.
Quality control of operations (columns 4, 5, 6, 7). It describes the composition of controlled operations, methods and methods of control, a list of metrology tools, the time of control (usually operational control is performed after the completion of production operations) and, if necessary, the services involved - construction laboratories, geodetic, geological and other services.
The need for material and technical resources in the production of work considered by the map is given in Tables 2.3 and 2.4.
The need for a tool, inventory is given for a separate link or brigade.
Table 2.3. The need for tools, inventory
Table 2.4. The need for materials, semi-finished products
The graphic part of technological maps includes plans and sections, diagrams, graphs, drawings provided for in paragraph II of paragraph 2.2, while the graphic materials should be extremely clear for understanding and should not contain unnecessary dimensions, designations.
The work schedule is drawn up in the form of table 2.5.
Table 2.5. Work schedule
Columns 1 to 9 of the work schedule fully correspond to columns 1 to 9 of the calculation of labor costs (Table 2.1).
The required number of machines and mechanisms (column l0) depends on the volume and nature of construction and installation work and the timing of their implementation.
The number of workers per shift (column 12) and the composition of the brigade are determined in accordance with the complexity and duration of work. When calculating the composition of the brigade, it is assumed that the transition from one seizure to another should not cause changes in the numerical and qualification composition of the brigade. Taking this into account, the most rational structure for combining professions in the brigade is established. Usually, teams have an established composition, which is taken into account when drawing up a work schedule.
The calculation of the composition of the brigade is carried out in a certain sequence:
outline a set of works entrusted to the brigade (according to column 2);
calculate the normative labor intensity of the work included in the complex (column 6), choose labor costs by professions and categories of workers from the calculation;
establish recommendations for the rational combination of professions; on the basis of data on the performance of the main lifting mechanisms for the implementation of the planned complex, the duration of the leading process is established;
calculate the number of units (column 11) and brigades;
determine the professional and qualification composition of the brigade;
calculate the design complexity (column 8).
To determine the quantitative and qualification composition of one brigade, you can use ENiRy.
The complex of work entrusted to the brigade includes all the work necessary for the smooth operation of the leading machine, all technologically related or dependent work. So, when erecting the above-ground part of large-panel houses, carried out in two cycles, the first cycle, along with the assembly work, includes all the work accompanying the installation (carpentry, special work, etc., ensuring the preparation of the house for painting work). During the construction of brick buildings in three cycles in the first cycle, the construction team is entrusted, along with construction and installation and related general construction work, providing preparation for plastering work. In the second and third cycles, plastering and painting works are carried out respectively.
In order for the numerical strength of the brigade to correspond to the performance of the leading machine, it is necessary to take as the basis for the calculation the term of work, determined based on the estimated time of operation of the machine or data from production experience.
The quantitative composition of each link nsv is determined on the basis of labor costs for the work assigned to the link, Qр (man-days) and the duration of the leading process T fur (days) according to the formula:
where: m is the number of work shifts per day (column 9).
The quantitative composition of the brigade is determined by summing the number of workers of all links that make up the brigade.
Labor costs by occupation and grade are established by sampling from the calculation of labor costs. The number of workers by profession and category is determined by the formula:
where Nbr is the total number of the brigade;
d - the proportion of labor costs by profession and category in the total labor intensity of work.
With an insignificant amount of work for any profession, which does not provide a full workload in settlement period, outline the combination of professions. The standard labor intensity of work performed in the order of combination should not exceed 15% of the total labor intensity of the work. Usually they combine the professions of an assembler and a carpenter, a carpenter and a concrete worker, an electric welder and an installer, an insulator and a roofer, etc. An approximate list of combined works is given in Table 2.6.
Table 2.6. An approximate list of combined works
| Installer constructions | Installation of precast concrete structures; installation of joinery in place; welding and rigging works; laying of concrete mix during the monolithing of structures. |
| Rigger | Rigging works; cooking bitumen, laying concrete mix at monolithic structures; sealing joints |
| Electric welder | Assembly of prefabricated structures; electric welding works; installation of metal fences; rigging |
| Mason | Masonry work; installation of precast concrete structures together with a qualified installer; device of scaffolding; laying of concrete mix during monolithing of structures; rigging work; plastering of individual places |
| Plasterer | Plastering works; facing of reinforced concrete staircases with mosaic boards; together with a qualified carpenter, filling the window and doorways and assembly of built-in equipment. |
| Filling openings; assembly and installation of built-in wardrobes; glazing; laying concrete mix when preparing under floors; hydro-isolation of bathrooms. |
|
| Transport | Together with qualified workers, filling joints of structures and window blocks; plastering surfaces; brickwork |
Number of shifts (column 13). When using basic machines (assembly cranes, etc.), the number of work shifts is at least two. The shift in work performed manually and with the help of a mechanized tool depends on the available front of work and the availability of workers. In addition, it is advisable to carry out certain jobs where high accuracy is required (alignment of columns) only during the day shift. The performance of a number of works on the second shift, especially in the autumn-winter period, requires additional measures for labor protection, lighting of workplaces, walkways, etc. However, the implementation of these measures does not completely eliminate the inconvenience of working on the second shift. Manual work is assigned to the second shift only in those rare cases when the scope of work is sharply limited and the team (link) is forced to split up for shift work.
Duration of work (column 14). First, the duration of mechanized work is determined, the rhythm of which determines the entire construction of the schedule, and then the duration of the manual work is calculated.
The duration of the mechanized work Tmech (days) is determined by the formula:
where: Nmach.-shifts. - the required number of machine shifts (column 9);
nmash is the number of cars;
m is the number of work shifts per day (column 13).
The required number of machines depends on the volume and nature of construction and installation work and the timing of their implementation.
The duration of work performed manually Tr (days) is calculated by dividing the labor intensity of work Qp (man-days) by the number of workers nh that can take the work front and by the number of shifts per day:
The maximum number of workers who can work on the grapple can be determined by dividing the work front into plots, the size of which should be equal to the shift productivity of a link or individual worker, as well as the number and productivity of lifting mechanisms. The product of the number of plots and the composition of the units gives the maximum number of the brigade in the given capture.
Minimization of duration has a limit in the form of three restrictions: the size of the work front, the availability of workers and the technology of work.
The work schedule (column 15) is given in the form of a line graph. The calendar dates for the performance of individual works are established from the condition of adherence to a strict technological sequence, taking into account the need to provide a front for the implementation of subsequent works as soon as possible.
The period of readiness of the work front in some cases increases due to the need to comply with technological breaks between two consecutive works. For example, the installation of overlying reinforced concrete structures can be carried out only after the monolithic joints of the supporting structures acquire the required strength (at least 70% of R28). Technological breaks are not fixed, they depend on a number of factors.
So, the drying time of the plaster depends on the period of the year, temperature and the methods used - natural or artificial ventilation. If necessary, work breaks can be shortened by using more intensive methods. So, when installing a monolithic joint, a different type and brand of cement, electric heating and other methods of accelerating concrete hardening can be used.
TYPICAL TECHNOLOGICAL CARD (TTK)
APPLICATION OF CONCRETE WITH ANTI-FREEZE ADDITIVES
1 area of use
1.1. The technological map is developed for concreting structures in winter conditions with the use of antifreeze additives.
1.2. Winter conditions are defined as conditions under which the average daily outside temperature is below 5 ° C and the minimum daily temperature is below 0 ° C.
1.3. The essence of the method of introducing antifreeze additives into a concrete mixture is to introduce additives into the concrete mixture during its manufacture that lower the freezing point of water, ensuring the reaction of cement hydration and its delayed hardening at negative temperatures.
1.4. Antifreeze additives are used in the case of construction in winter conditions of monolithic concrete and reinforced concrete structures, monolithic parts of precast-monolithic structures, monolithic joints of prefabricated structures.
1.5. The composition of the work considered by the technological map includes:
Laying concrete mix with anti-freeze additives;
1.6. Concreting in winter conditions with the use of antifreeze additives is performed in accordance with the requirements of federal and departmental regulations, including:
SNiP 3.03.01-87. Bearing and enclosing structures;
SNiP 12-03-2001. Labor safety in construction. Part 1. General requirements;
SNiP 12-04-2002. Labor safety in construction. Part 2. Construction production.
- "Guidelines for the production of concrete work in winter conditions, regions of the Far East, Siberia and the Far North". Moscow, Stroyizdat, 1982;
- "Guidelines for the production of concrete works". Moscow, Stroyizdat, 1975;
- “Guidelines for quality control of construction and installation works”, St. Petersburg, 1998.
2. Organization and technology of work
2.1. Before starting the device, the robot for the application of concrete mixtures with antifreeze additives in winter conditions must:
Execute and accept the underlying structures;
Prepare tools, devices, inventory;
Deliver materials and products to the workplace,
To instruct workers on labor protection;
To acquaint performers with the technology and organization of work.
2.2. The use of concrete mixtures with antifreeze additives includes:
Choice of antifreeze additives;
Preparation of concrete mixture with anti-freeze additives;
Transportation of concrete mix with anti-freeze additives;
Laying concrete mix with anti-freeze additives;
Curing of concrete with anti-freeze additives;
Quality control and acceptance of works.
2.3. As antifreeze additives, it is possible to use chemical substances, the characteristics of which are given in table. 2.1. Complex additives containing compatible plasticizing and antifreeze (simultaneously accelerating hardening) components are recommended.
2.4. The area of application of concretes with antifreeze additives and hardening accelerators are given in table. 2.2.
2.5. The antifreeze additives listed above have a different mechanism of influence on the process of concrete structure formation. Some of them only reduce the freezing point of water and do not affect the rate of setting and hardening of concrete (for example, НН, М).
Other additives, along with effective antifreeze properties, are simultaneously accelerators of setting (P) and hardening (NK, NNK). The approximate strength of concrete with antifreeze additives is given in Table 2.3.
2.6. The optimal amount of antifreeze additive depends on the minimum temperature of the concrete mix. When curing concrete with antifreeze additives, it is necessary to create such conditions that during the period of transportation and laying the concrete mixture does not cool below 0 ° C. In this case, the optimal amount of antifreeze additives should correspond to the data in table. 2.4.
2.7. Concrete mixtures with additives NK, NNKi, especially P, are characterized by accelerated setting times, which makes it difficult to lay the concrete mixture and degrades the structure of the cement stone. Therefore, simultaneously with the specified antifreeze components, it is recommended to introduce plasticizing agents into the concrete mixture. As a plasticizing component of a complex additive that increases the mobility and reduces the water demand of the concrete mixture, it is recommended to use the additives given in table. 2.5.
Concrete with the addition of potash should have a negative temperature during setting and initial hardening.
2.6. The most effective complex additives are formulations including surfactants (surfactants) and electrolytes. With correctly selected dosages of electrolyte and surfactant additives, it is possible to use the plasticizing properties of the latter and at the same time to obtain a high hardening rate. The list of the most effective complex antifreeze additives and their reduced amount is given in table. 2.5.
2.7. The recommended amount of chemical additives for complex concrete curing is given in Table .. 2.6. The use of concretes with antifreeze additives should be preceded by laboratory tests of the effect of the additives on the strength and speed of concrete hardening.
2.8. The final choice of the type of chemical additives is made taking into account the prices of manufacturers and suppliers of chemical additives.
2.9. The preparation of the concrete mixture is organized at the concrete plant. The selection of the concrete composition for winter laying is performed in accordance with GOST 27006-86. The selection of the composition is performed by calculation and experimental method, which includes the solution of the following issues:
Determination of all requirements for the quality of concrete mix and concrete;
Quality assessment and selection of materials for the preparation of concrete mix;
Calculation of the nominal composition of concrete;
Experimental verification of the calculated composition;
Correction of the composition and calculation of the production composition of concrete.
2.10. When preparing a concrete mixture, it is possible to heat the mixing water, heat or heat the components, as well as heat the concrete mixing unit, metering and bunker compartments.
2.11. To obtain the maximum temperature of the concrete mix at the outlet of the concrete mixer, the water is heated up to the maximum possible temperature of + 80 ° C.
2.12. The mixing time of the concrete mixture in the concrete mixer should be 25% longer than in summer conditions, and not less than the values given in table 2.7.
2.13. The amount of chemical additives established in accordance with the recommendations is introduced during the preparation of concrete mixtures in the form of aqueous solutions of working concentration. Salt solutions are prepared in water heated to 40 ° C in mixers. The main indicators of aqueous solutions of antifreeze and plasticizing additives are given in table. 2.8, Table 2.9.
2.15. Transportation of the prepared concrete mix is carried out by concrete mixer trucks. To minimize heat loss, the open parts of the mixer drum are covered with moisture-proof materials and insulated. The neck of the drum of a concrete mixer is insulated and closed with a heat-insulating cover or the neck is heated with exhaust gases from the engine. When using only potash, it is recommended to add it at the facility by introducing an aqueous solution of potash with mixing all components in the drum of a concrete mixer. The place of transfer of the concrete mixture from the drum of the concrete mixer should be to the rotary hopper protected from wind and atmospheric precipitation. The bunker for supplying concrete mix must also be insulated.
2.16. When using concrete pumping units for supplying concrete mix, all units and parts in contact with the concrete mix are insulated. At the same time, especially carefully insulate the pipelines and the main units of the concrete pump in order to maintain the initial temperature of the concrete. At extreme temperatures up to -40 ° С, in addition to the insulation of the main units of the concrete pump, additional heating of the insulated concrete pipeline is required with flexible heating elements... There should also be provision for the availability of hot water in insulated tanks for washing concrete pipes after concreting.
2.17. The curing of monolithic concrete and reinforced concrete structures erected from concrete with antifreeze additives is carried out in compliance with the following instructions:
Concrete surfaces not protected by formwork, in order to avoid moisture loss or increased moisture due to precipitation, should be immediately covered with a layer of waterproofing material (plastic wrap, rubberized fabric, roofing material, etc.) at the end of concreting;
Concrete surfaces that are not subsequently intended for monolithic connection with concrete or mortar can be coated with film-forming compounds or protective films (bitumen-ethinoleic, ethinol varnish, etc.);
In case of an unforeseen decrease in the temperature of concrete below the design structure, it is necessary to insulate or heat up until the concrete gains critical strength.
2.18. Stripping of load-bearing concrete and reinforced concrete structures should be carried out after the concrete reaches the strength given in table. 2.9.
2.31. If it is impossible to ensure the required strength of concrete by the time the structure is loaded with a standard load, it is allowed, with an appropriate feasibility study, to use a concrete class increased by one step.
2.32. It is allowed to remove the formwork that absorbs the mass of concrete of structures reinforced with load-bearing welded frames, as well as side elements that do not bear the load from the mass of the structures, after the concrete reaches its critical strength.
2.33. The strength of the concrete before stripping must be confirmed by tests.
2.34. Removal of thermal protection and formwork from structures, when using concrete with antifreeze additives, upon reaching the strength specified in section 3.
3. Requirements for quality and acceptance of works
3.1. When holding concrete with antifreeze additives in winter conditions, production quality control is carried out, which includes:
Incoming control of materials for the preparation of concrete mix, reinforcement and embedded parts, heat-insulating materials;
Operational control of implementation reinforced concrete works;
Acceptance control of the work performed.
At all stages of work, inspection control is carried out by representatives of the customer's technical supervision.
3.2. Incoming quality control of materials, semi-finished products, products and parts consists in checking by external examination their compliance with GOST, TU, project requirements, passports, certificates confirming the quality of their manufacture, completeness and compliance with their working drawings. During the incoming inspection, the observance of the rules for unloading and storage is also checked. Incoming control is performed by line personnel upon receipt of materials, structures, products at the construction site.
3.3. Operational control should be carried out during the performance of reinforced concrete work and ensure the timely identification of defects and the adoption of measures to eliminate and prevent them. During operational control, the compliance of the work performed with the working project and regulatory requirements is checked. The main tasks of operational control:
Compliance with the technology for performing reinforced concrete works;
Ensuring the compliance of the work performed with the project and the requirements of regulatory documents;
Timely identification of defects, the reasons for their occurrence and taking measures to eliminate them;
Performing subsequent operations after eliminating all defects made in previous processes;
Increasing the responsibility of direct executors for the quality of their work.
3.4. When laying concrete mix, it is necessary to control:
The quality of the concrete mix;
Rules for unloading and distribution of concrete mix;
Concrete mix temperature;
Concrete compaction mode;
Concreting procedure and ensuring the solidity of the structure;
Timeliness and correctness of sampling for the manufacture of control samples of concrete.
3.4. When laying and compacting concrete mixture with antifreeze additives, laid in winter conditions, the requirements given in table must be followed. 3.1.
3.5. When holding concrete with antifreeze additives, control:
Maintaining temperature and humidity conditions;
Protection of hardening concrete against mechanical damage;
Concrete holding time.
3.6. Technical requirements for holding concrete with antifreeze additives are given in table. 3.2.
3.6. Concrete quality control provides for checking the compliance of the actual concrete compressive strength in the structure with the design and specified in the time of intermediate control. The compressive strength of concrete should be checked by testing control cube samples with dimensions of 100x100x100 mm in accordance with GOST 10180-90. Test pieces are made from samples of the concrete mixture used. Samples are taken at the place of preparation of the concrete mixture and directly at the place of concreting.
At the place of concreting, at least two samples should be taken. One series of control samples is made from each sample (at least three samples in a series). Control samples are concreted in steel detachable forms corresponding to GOST 22685-89. Before concreting, the inner surfaces of the molds are lubricated. The concrete mixture is placed in molds immediately after sampling with bayonet or vibration compaction. Control samples are stored under conditions of concrete hardening of the structure. De-lay the samples after curing the structure.
The timing of testing control samples is assigned by the construction laboratory, taking into account the achievement by the time of testing design strength... Samples stored in frost, before testing, should be kept for 2 ... 4 hours at a temperature of 15 ... 20 degrees C. Intermediate control is carried out after the temperature has dropped to the calculated final temperature.
3.7. When accepting a sustained structure, check:
Conformity of the design to the working drawings;
Compliance with the quality of concrete to the project;
The quality of materials used in the construction, semi-finished products and products.
3.8. The requirements for the finished design are given in table. 3.3.
...
