Technological process for preparing 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 TP Bagirova) based on the materials of the Rostov research vessel of the Orgtransstroy Institute.
I. SCOPE
The technological map was 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 a common complex of machines and mechanisms for the construction of cement-concrete pavements of highways.
The open-type storage of sand and fractionated crushed stone with dividing walls is located next to the mixing plants. The warehouse must have a stock of materials sufficient to operate the units for 10 days. Sand and fractionated 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 section by bucket loaders of TO-18 or Case type.
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, drainage 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 vehicles 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 unit 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.
Technical specifications
Productivity, m3 / h. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .60
Number of aggregates fractions:
sand. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .1
crushed stone. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .3
Largest aggregate size, 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 shaft axis;
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 the exhaust air before it is removed to the atmosphere and automatic indicators of the lower and upper levels;
dosing unit, consisting of four supply bins 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.
Flow diagram of the pulp and paper mill operation with the SB-78 mixer:
1 - feeders; 2 - conveyors; 3 - two-armed estrus;
4 - filler 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 - hose for diverting water to a concrete mixer truck;
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 production of cement concrete mix, 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 to 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 mixture composition.
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 batches are made in a semi-automatic mode.
At this point, 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.
Mix preparation
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 into 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 fed through a pipeline directly to the mixer.
When preparing the 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 - sulfite-yeast mash (SDB) in the amount of 0.2 - 0.25% and sodium abietate (neutralized air-entraining resin - SNV) in the amount of 0.02 - 0.03% of the weight of the 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, when the concrete mix is \u200b\u200bfinished, 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 performed, then the mixer is washed with water, and the jaw gate of the storage hopper is also cleaned.
The rest of the plant components are cleaned with compressed air.
During the shift and at the end of the work, the access roads and plant grounds 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 CBP and the Central Laboratory of the Construction Administration. The quality of the materials is checked by visual inspection and by sampling and testing samples.
Every day, at the beginning of the first shift, a representative of the CBZ 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 SU 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 should 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 rubble 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 rules are allowed to work on the mixing plant.
All personnel serving the unit must be provided with protective clothing 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.
Exposed live parts of shields, contact parts of plug connections, switches and switches of electrical machines must be protected by covers or casings.
It is forbidden to make minor repairs during the work of the plant. The 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 must only switch on individual plant units 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-B.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 dosing unit 3 bit - 1; electrical fitter 5 bits - 1. Operator 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 health of the units and units of the installation.
The operator 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 the uninterrupted supply of cement to the cement feed bin.
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.
The auxiliary worker regulates the approach of dump trucks for loading, keeps records of the prepared mixture and draws up invoices.
IV. SCHEDULE OF THE PRODUCTION PROCESS
(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│├───────────────┬───────────────┤
││ shifts volume 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 bits - 1││
│Cooking│100 m3│ 6.4 │90│Help
│cement concrete ││││machinist││
│and concrete mix││││ (locksmith││
│ (material supply - ││││ construction) ││
│lov in consumables ││││ 4 bits. - 1││
│bunker, ││││Machinist││
│continuous ││││loader TO-18││
Озdosing││││ 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││
├─────────────────┼──────┼─────┼───────┤ 5 bits - 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. 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 THE MIXER SB-78
(shift capacity 320 m3)
────────┬─────────────────────┬──────────────┬──────┬─────┬─────┬─────────┬───────┬─────────
Code │Description of work Composition of the link │Unit- │Volume│Norm│Price, │Norm- │Cost
norms││ (brigades) │nice│work│time- │rub.-kop.│active │ costs
│││ism e- name ││time│work
To the whole to the whole
│││││││volume│volume
│││││││ works, │ works,
│││││││pers.- 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│Setting the dispenser│installation││││││
trust и cement and check 6 bit. - 1││││││
"Dondo r- the work of all│Help││││││
the 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 in "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 bit - 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
││Аgraph 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 additional operations are included in this technological cycle. So, when concreting structures in conditions of negative temperatures, it is necessary to heat aggregates and water; when using concretes with additives (anti-freeze, plasticizing, pore-forming, etc.), an aqueous solution of these additives should be prepared beforehand.
According to the degree of readiness, concrete mixes are subdivided into: ready-to-use concrete mixes (BSG); partially closed concrete mixes (BSChZ); dry concrete mixtures (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 concrete mixture produced.
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, the mixers are gravity and forced mixing. IN 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, carried away by the drum blades, are mixed. IN forced stirring 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 belong to the concrete mixers with forced mixing.
The size of the concrete mixers is determined by the useful capacity of the mixing drums, which is determined by the total volume of dry materials loaded into one 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 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 take place 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 mixture 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 mix 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 influence 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 bins, 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.
Figure: 13.1. Layout diagrams of concrete mixing plants:
and) 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 preparation plants of precast concrete products enterprises, as well as on-site concrete preparation plants. If the object is far from the place of concrete preparation at a distance that does not allow transporting the ready-made concrete mix 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;
the volume and intensity of concrete work;
technological capabilities of the used concrete mixing equipment, etc.
District factories supply with ready-made mixtures construction objects located at distances not exceeding technologically permissible distances for 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.
Regional factories are designed to produce 100 ... 200 thousand m 3 of concrete mixture per year. 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 a metal frame in the shape of a rectangle 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 bunker compartments in accordance with the brand.
Level indicators, provided in the bunker 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 go to the hopper and then to 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 special containers 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 \u200b\u200btheir operation the consumption of products is guaranteed for 10 ... 15 years.
Onsite factories usually serve one large construction site for 5 ... 6 years. Such factories are made as collapsible modular 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 object with a monthly demand for concrete up to 1.5 thousand m 3. Installations are arranged according to the parterre scheme (Fig. 13.2).
Figure: 13.2. Scheme of the inventory concrete mixing plant:
1 - boom scraper; 2 - cement bunker; 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 that exceed technologically permissible. Such installations increase the flexibility of the system for centralized provision of ready-mixed concrete for construction sites.
22. Technology of preparation of concrete mix
The technological process of concreting structures includes the preparation of a concrete mixture and its transportation to the facility under construction, its supply, distribution, laying and compaction in the structure, and maintenance of concrete during the hardening process.
The concrete mix cannot be prepared in advance and transported over long distances. After preparation, it should 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 way in the summer does not exceed 1 hour.
The concrete mix is \u200b\u200bprepared 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-made concrete mixture to vehicles. In winter conditions, this technological process includes additional operations.
The concrete mix is \u200b\u200bprepared 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 dry concrete mixture. The main technical means for the production of concrete mix 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 components of the concrete mix are first lifted into the feed bins, then they are lowered by gravity, passing through their own batchers, fall into the common receiving funnel and rise again upward to be loaded into the concrete mixer. The advantage of this scheme is the lower cost of installation, and the disadvantage is the large building area.
When the need for a concrete mix is \u200b\u200bnot more than 20 m 3 / h, mobile concrete mixers with gravity-type mixers are usually used.
Figure: 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 - supply bins; 5 - cement supply pipeline; 6 - cement batcher; 7 - filler dispenser; 8 - water dispenser; 11 - concrete mixers; 12 - dispensing hopper; 13 - concrete truck; 14 - 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 that exceed 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.
Cyclic concrete mixer performance
P \u003d q n k w / 1000, m 3 / h
where q is the volume of ready-mix 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 batching concrete 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 flexibility 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.
There are certain requirements for the concrete mix:
1) it must maintain uniformity (during transportation, reloading and laying in formwork), which is ensured by connectivity (non-segregation) and water retention capacity. All this is achieved by the correct selection of the composition of the mixture, the accuracy of 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 size composition of the mixture, the amount of water, the degree of reinforcement, methods of transportation and compaction of the mixture.
Dry construction mix (CCC) 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 to obtain higher technical characteristics of the finished product in comparison with mixtures obtained at the construction site. An important advantage of dry mixes is the ability to add 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 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, vibratory 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 transportation distance and the lifting height. With any method of transportation, the mixture must be protected from atmospheric precipitation, freezing, drying, as well as from the flow of cement milk.
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 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 (productivity, travel speed, unit cost of transportation). In addition, it is also necessary to take into account the requirements to preserve the properties of the concrete mixture - to prevent decomposition, changes in homogeneity and consistency.
For transporting 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 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 efficient means of transportation. Concrete mixer trucks are loaded at the factory with dry components and are prepared with concrete on the way or at 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 shallowly buried) or reloaded into intermediate containers for subsequent delivery to the concreting site.
The mixture is fed to the structures to be concreted by cranes in fixed or swivel buckets or by belt conveyors (conveyors), concrete pumps and pneumatic blowers (through pipes), link trunks and vibrating trunks, belt pavers. Swivel buckets with a capacity of 0.5 - 8 m 3 are loaded directly from dump trucks or concrete trucks. Belt mobile 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 long 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 belt conveyors are more effective in this respect. concrete paversmounted on the basis of a tractor, equipped with a skip hoist and a belt conveyor up to 20 m long.To supply the mixture to structures located in cramped conditions and in places not accessible to other means of transport, use 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. Also, for the uninterrupted supply of the mix and its laying, they use pneumatic blowers... The maximum range 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 on 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 vibrobot with a diameter of 350 mm, vibrators-stimulators and dampers are installed every 4-8 m.
The supply and distribution of concrete mixture in the structure at a distance of up to 20 m with a slope to the horizon of 5-20 ° is provided vibrating grooves in conjunction 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:
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ROUTING
TECHNOLOGICAL CARD FOR CONCRETING 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 during work | ||
| Environmental protection | ||
| List of references | ||
| 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 technology for the production of preparatory formwork, reinforcement and concrete works, aimed at ensuring the high quality of the structures being built.
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. Compliance with the requirements of the regulations guarantees that the concrete will obtain 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;
Minimizing 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 temperature cracks.
1.10. The technological measures include the measures set forth below in this "Technological Regulation".
1.11. Concrete work must be carried out in accordance with the project, PPR, this "Technological Regulation", 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 bridge construction", 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 manual work - using a mechanized tool.
1.13. Responsibility for the quality of the work performed on the construction of 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 this "Technological Regulation".
1.14. Concreting and erection of concrete structures are carried out under the supervision of the contractor and in each shift - a shift master.
1.15. During the production of concrete work on 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 a guarantee for the quality of the concrete mixture supplied to the construction site.
The application for the supply of concrete mix is \u200b\u200bdrawn up by the CONTRACTOR-PERFORMER OF WORKS on the plant's form with the obligatory indication of the consumer of the concrete mix (CONTRACTOR-PERFORMER OF THE WORKS), 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 amount 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 Complex moisture-and-heat protective equipment consists of:
Inventory metal formwork with forming surface;
Moisture and heat protection 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 a 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-proof panels of an inventory moisture-and-heat protective coating.
3.5. As heat-shielding materials, panels of geotextiles, dornite, flax wool or other heat-insulating roll materials can be used.
3.6. In addition to the complex moisture-and-heat-protective technological equipment, the concreting section must 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, if necessary, concrete;
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 concrete;
3.7. Heat houses 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 coatings to the base and previously concreted concrete and reinforced concrete elements.
3.9. To reduce the risk of cracking in the contact zone of the hardening concrete with the hardened greenhouse, 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 switch on or off to smoothly regulate the air temperature in the greenhouse.
3.15. The tepus must have a rigid structure capable of withstanding the own weight of the fences, wind pressure, snowfall, etc.
3.16. The building 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 heat 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 cooling the concrete on the surface of the grillages to a temperature that does not exceed the outside air temperature by more than 20 ° C.
The projected minimum temperature should be taken as the design temperature for the next day.
Table 1
| Appointment of equipment or tooling | Equipment or tooling | Description, brand. | Quantity (pcs.) | Notes |
|
| Concrete supply | Concrete pump | "SHCVING" Lstr \u003d 42 m | |||
| Concrete compaction | Deep vibrator, d \u003d 50 mm, l \u003d 35 cm. | ||||
| Installation work | Crane l / c 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 work for the construction of concrete structures, geodetic alignment work 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, steel grade of reinforcement 25G2S, reinforcement with a diameter of 10 mm, 8 mm of class AI, grade of steel St5 sp. GOST 5781-82.
The order of storage of reinforcement and angle.
Steel reinforcement is stored in a specially designated area. Reinforcement packages are laid on wooden lining and covered with a 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 bar.
Reinforcement cleanliness.
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 \u003d 1.6 mm. Reinforcement build-up is performed with an overlap using knitting wire, the overlap of the reinforcement bars is at least 30 reinforcement diameters. In one section, no more than 50% of the rod joints should be located.
4.7. Prior to the commencement of work on the concreting of structures, the required number of spacer gaskets, "crackers", should be made to ensure the required thickness of the protective layer and the design position of the reinforcement 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 \u200b\u200bof 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 positions) and embedded parts, their installation and installation in the formwork and other work related to the design features of the reinforcement of the elements to be concreted, is performed in accordance with the 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 boreholes 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. Completed formwork sections are made on site. For the 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 leakage of cement mortar during concreting, all detected places should be reliably sealed before applying the lubricant by gluing with adhesive tape (construction tape) 30-40 mm wide or smeared with sealant. The joints of the formwork panels are sealed with silicone or other sealants. Formwork panels must be fastened and fixed (with racks, 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 when installing the formwork panels.
4.16. After an instrumental check of the position of the reinforcement cages, 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 Prior to the commencement of concrete placement, the equipment for supplying concrete should be prepared for operation and its serviceability should be checked.
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 there is a standard cone at the facility for determining the flow of concrete, thermometers for measuring the temperature of the concrete mixture and outside air, a device for determining the amount of entrained air in the concrete mixture and the sufficiency of molds for making control cubes from concrete.
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 structural elements to be concreted, the intensity of laying 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 mixture must be checked and specified on the basis of trial pumping of the concrete mixture.
The internal surfaces of the concrete pipeline must be moistened and lubricated with lime or cement mortar before concreting.
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 longer than the specified time, the concrete pipeline must be emptied and flushed.
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 concrete delivery.
5.9 When performing work in the winter period, before concreting each element, the base and the upper zone of previously concreted elements should be warmed up to a temperature of at least + 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 moistened abundantly 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 structure to be concreted in layers of the same thickness 25-30 cm (but not more than 40 cm), without breaks, with a consistent direction of laying 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 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 its compaction should not exceed 30 °.
5.16 The supply, distribution and compaction of the concrete mix in each layer must be done only "from the bottom up".
5.17 Before compaction of each layer to be laid, the concrete mixture should 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 carrier. It is prohibited to use vibrators for redistribution and leveling of concrete mix.
5.18 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 concrete mixture stops settling and the shine of the cement paste appears on the surface.
5.19 When performing 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 is laid.
5.20 After placing the concrete mixture in the first layer of the structure to be concreted, the concrete pump is turned off, the concrete pipes are transferred to its end surface and the concrete mixture is distributed in the second layer. Vibration compaction of the concrete mix is \u200b\u200balso 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 uniformity 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 with the 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-proof coating on top of the grillage), disassemble the greenhouse, the formwork is allowed under the restrictions set forth in paragraph 3.18 and paragraph 3.19 of this "Technological map".
In this case, the minimum predicted outdoor temperature for the next 24 hours should be taken as the design ambient temperature.
6.4 When holding concrete, the predicted strength of concrete must 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 in performing 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 specifications.
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 the customer's technical supervision with the registration of the Act in 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 mixture - plasticity is determined in each concrete mixer truck;
Measurement of 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 a laboratory assistant at the time of unloading the concrete mixture into a concrete pump.
During the work, the following information on concrete is recorded:
Date of concreting of each block, class of concrete, duration of laying the mixture, position of the concreted structure.
Details of the concrete mix, including the nature and source of each of the composite materials, the source of 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.
Results of tests 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, kept up to date, and made 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 concreted structure, 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 \u200b\u200bthe 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, sawn timber are checked for compliance with certificates and shipping documents, an external examination is performed 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 put into production !!!
7.8. The contractor carries out operational control.
Operational quality control is carried out in the course of the following construction works:
Installation and dismantling of formwork;
Installation of fittings and embedded parts;
Concrete laying;
Curing.
Operational control must ensure timely detection 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;
The results of operational control should be recorded in the "General work log", as well as in special work logs, including 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 schemes for 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 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 building height, 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 building height, 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 irregularities 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. Dimension of cross-section of 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 supporting element, actuator circuit |
|
| 7. Slope of the supporting surfaces of foundations when supporting steel columns without grout | The same, every foundation, executive scheme |
|
| 8. Location of anchor bolts: | The same, each foundation bolt, executive diagram |
|
| in plan within the contour of the support | ||
| in plan outside the support contour | ||
| in height | ||
| 9. The difference in elevation at the junction of two adjacent surfaces | The same, each joint, executive scheme |
Formwork from panels
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).
The incoming reinforcing steel must be recorded in the Incoming Inspection Log.
During 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 more than 1 m thick | ||
| 3. 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 structure cross-section, 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 works
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. 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. | Checking in accordance with GOST 10181.1-81 with registration in the journal of concrete work, concrete care, the Act of making 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. 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 based on 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 application 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-protective 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 during 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
Individuals who have reached the age of 18, who have been recognized as fit for this work by the medical commission, who have been trained in safe methods and techniques of work and instructions on labor safety, and have a certificate for the right to work as a concrete worker, are allowed 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 put into effect, 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 supervisory authorities, during work interruptions for more than 30 calendar days. Target instruction 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, not shielded by electrical devices on the site. When working with a power tool, a concrete worker must be trained and have I qualification group for safety.
Before starting up 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 master about it.
Upon receipt of the tool, you must make sure that it is in good working order, the faulty tool 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 examination. 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 a hat, 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 joints. 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 the concrete pump for testing at idle 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 bunker, 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 the metal trunks to each other;
Condition of protective shields 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 ground contact is intact;
The switch is working properly;
The casing tightness bolts are well tightened;
The joints of the vibrator parts are tight enough, and the motor winding is well protected from moisture ingress;
The shock absorber on the vibrator handle is in good condition, and is 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 housing operating at 127 V or 220 V.
It is possible to 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 wire or cable while moving it.
In the event of a break in live wires, sparking 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.
When it rains, the vibrators should be covered with tarpaulins or stored indoors.
During breaks in work, as well as when concrete workers move from one place to another, the vibrators must be turned off.
The concrete worker working with the vibrator must not allow water to enter 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 and 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 fences or in the case of a short period of employees being 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 in 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. Electrical 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 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 harm to human or animal health.
All sites and buildings are kept clean and tidy. All working personnel have been instructed against signature, recorded 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 coating. Waste reinforced concrete structures will be removed by special transport for placement at the landfill;
Washing of concrete mixer trucks and 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 road 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. If 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 minimum and temporary land alienation, disturbance of vegetation cover.
In order to minimize the negative impact on the flora and fauna, during the construction period of the facility, the CONTRACTOR-PERFORMER of WORKS must take 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;
Equipment operation only within the boundaries of the construction site allotment using the existing access roads;
During the construction period, the protection of fauna, first of all, will consist in compliance with environmental legislation, minimizing the impact on the atmospheric air, surface water, 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:
Use of crushed stone road surfaces, 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 the WORKS should use only serviceable construction equipment with regulated fuel equipment that 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 particular attention to 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 inspection 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, in order to reduce dustiness on access or working roads, constant watering of the road surface with water sprinklers should be carried out.
9.4. Plan CONTRACTOR-PERFORMER OF WORKS on 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:
Industrial (construction waste);
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 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 specified period of their operation;
Use of waste as raw material in a new technological cycle;
Shift foremen are responsible for compliance with environmental protection requirements.
List of references
| GOST 2379-85 | ||
| GOST 7473-85 * | Concrete mixes. Specifications |
|
| 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. Specifications |
|
| 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 | Reinforcement and embedded products welded joints welded reinforcement 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 | Supporting and enclosing structures |
|
| SNiP 3.06.04-91 | Bridges and pipes |
Appendix 1
snipov.net
VET
TECHNOLOGICAL CARD NO.
for concrete work
1 Scope .. 3
2 organization and technology of work execution .. 3
3 REQUIREMENTS FOR THE 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 normative 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 mixture 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 components of concrete mixtures should be done 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 with 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 content, granulometry of aggregates and control of strength.
When preparing a concrete mixture using separate technology, the following procedure should be observed:
- water, part of the 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 rest 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 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 concrete has reached 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;
- 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 construction, semi-finished products and products.
Acceptance of completed concrete and reinforced concrete structures or parts of structures should be formalized in the prescribed manner by an act of inspection 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 duties 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 regulations 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. LABOR PROTECTION AND INDUSTRIAL SAFETY
Workers performing work must pass a knowledge test and have with them certificates of knowledge testing on labor protection.
Employees who have not previously been trained in safe labor 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.
The 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 the 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, are personally liable for personal, disciplinary, administrative, material and criminal liability. 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. Supporting 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. Building. 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. Labor protection and industrial 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 of 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 oil trunk pipelines.
| Item No. | Full name | Employee position | date | Signature |
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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 diploma works 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.
Technological maps are mandatory for use by work manufacturers, foremen and foremen as a guide for 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.
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SNiP 3.03.01-87. Supporting and enclosing structures;
SNiP 12-03-2001. Labor safety in construction. Part 1. General requirements;
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