Safety and labor protection in the production of stone works. Safe bricklaying practices

7. SAFETY AND PROTECTION IN THE PRODUCTION OF STONE WORKS

7.1.

Safe bricklaying practices

Safety is a set of measures and rules, with strict observance of which working conditions are ensured that are safe for life and health.

Before work the bricklayer needs to be instructed on safe methods and techniques for performing the production task; inspect workplace and check the correct placement of materials; check the serviceability of tools, inventory, fixtures; establish the presence of external protective visors and fences in the openings; put on overalls and a protective helmet.

When laying from scaffolds or scaffolding(Fig. 7.1) the following requirements must be met:

1) the working platform should be located 150 mm below the top of the masonry;

2) the width of the flooring must be at least 2 m, and the flooring itself must have flat surface and do not bend when walking;

3) the gap between the masonry and flooring should not exceed 50 mm;

4) with a flooring height of not more than 1 m, scaffolding and scaffolding must be
fenced with railings with a height of at least 1.1 m, consisting of a handrail, a horizontal intermediate element and a side board;

5) when placing masonry materials along the laid out wall there should be a passage of at least 60 ... 70 cm.

Rice. 7.1. Storage of masonry materials
on the scaffold

Supply of bricks and mortar. ceramic brick, a stone on pallets with supporting bars is served at the mason's workplace with a pick-up case, consisting of two L-shaped half-cases with gripping levers, which are brought under the pallet shield (Fig. 7.2).

Wall materials on pallets with hooks at the ends are served with a grip-case with a rigid fence. The end brackets, pivotally connected to the grip frame, are hooked onto the four hooks of the sling and the pallet is fed to the mason's workplace (Fig. 7.3).

Brick arriving atconstruction site without pallets, served self-tighteningcapture (fig. 7.4 and 7.5). The mass of the package with the grip is 1.9 tons, therefore, it is allowed to install a brick with such a grip only on reinforced scaffolds. If the scaffolding and scaffolding are not designed for such a load, then the top six rows of the package are first lifted with a grip, then the bottom four.

Rice. 7.3. Supply of bricks on pallets with hooks: a– putting cases on the pallet; b- fixing the fence for the hooks of the pallet; 1 - pallet hooks; 2 - case body; 3 - hard fencing

Rice. 7.4. Feed self-tightening
capture: 1 - a package of silicate bricks;
2 - self-tightening grip

Rice. 7.5. Innings masonry mortar:
a- distributing hopper;
b- in boxes tied with a garland

The solution is supplied by a dispensing hopper moved by a crane (Fig. 7.5). At workplaces, masons' boxes are filled with mortar from a hopper, the volume of which allows filling up to five mortar boxes.

Boxes loaded with mortar are delivered to the workplace.

When supplying masonry materials, it is forbidden to be under the supplied load. The arrangement of materials on the working floor of scaffolds and scaffolding, as well as on the ceilings, is carried out in accordance with the scheme approved by the project for the production of works.

In the process of laying the bricklayer observes the following safety measures (Fig. 7.6):

- monitors the correctness hand tool, the working surfaces of which should be even, and the wooden handles should be tightly fitted and wedged;

– works in mittens;

- performs jointing of external seams after each row in such a way as not to be on the wall;

- he performs cutting and cutting of bricks in goggles;

- protects the laid out openings or inserts window or door blocks into them;

- the masonry at the level of the floors is completed in the form of a ledge (side), rising 150 mm above the laid floor;

- when laying out the outer pilasters, when you have to stand on wall, puts on a safety belt and is fixed to stable parts of the building.

Rice. 7.6. Measures to ensure masonry safety: a- fencing of openings;
b– device of the side in the level floors;in– work with a safety belt; 1 - inventory fence; 2 - side; 3 - safety belt; 4 – halyard fixed to the stable structures of the building

Safety is a set of measures and rules, with strict observance of which working conditions are ensured that are safe for life and health.

Before work the bricklayer needs to be instructed on safe methods and techniques for performing the production task; inspect the workplace and check the correct placement of materials; check the serviceability of tools, inventory, fixtures; establish the presence of external protective visors and fences in the openings; put on overalls and a protective helmet.

When laying from scaffolds or scaffolding (Fig. 7.1) the following requirements must be met:

1) the working platform should be located 150 mm below the top of the masonry;

2) the width of the flooring must be at least 2 m, and the flooring itself must have a flat surface and not sag when walking;

3) the gap between the masonry and flooring should not exceed 50 mm;

4) with a flooring height of not more than 1 m, scaffolding and scaffolding must be
fenced with railings with a height of at least 1.1 m, consisting of a handrail, a horizontal intermediate element and a side board;

5) when arranging masonry materials along the laid out wall, a passage of at least 60 ... 70 cm must remain.

Rice. 7.1. Storage of masonry materials
on the scaffold

P

Rice. 7.2. Supply of bricks on pallets with transverse bars with a pick-case:1 - pallet with transverse bars;2 - L-shaped half-case

Wall materials on pallets with hooks at the ends are served with a grip-case with a rigid fence. The end brackets, pivotally connected to the grip frame, are hooked onto the four hooks of the sling and the pallet is fed to the mason's workplace (Fig. 7.3).

Brick arriving atconstruction site without pallets, served self-tighteningcapture (fig. 7.4 and 7.5).The mass of the package with the grip is 1.9 tons, therefore, it is allowed to install a brick with such a grip only on reinforced scaffolds. If the scaffolding and scaffolding are not designed for such a load, then six top rows package, then the bottom four.

Rice. 7.3. Supply of bricks on pallets with hooks:a – putting cases on the pallet;b - fixing the fence for the hooks of the pallet;1 - pallet hooks;2 - case body; 3 - hard fencing

Rice. 7.4. Feed self-tightening
capture:1 - a package of silicate bricks;
2 - self-tightening grip

Rice. 7.5. Supply of masonry mortar:
a - distributing hopper;
b - in boxes tied with a garland

The solution is supplied by a dispensing hopper moved by a crane (Fig. 7.5). At workplaces, masons' boxes are filled with mortar from a hopper, the volume of which allows filling up to five mortar boxes.

Boxes loaded with mortar are delivered to the workplace.

When supplying masonry materials, it is forbidden to be under the supplied load. The arrangement of materials on the working floor of scaffolds and scaffolding, as well as on the ceilings, is carried out in accordance with the scheme approved by the project for the production of works.

In the process of laying the bricklayer observes the following safety measures (Fig. 7.6):

– monitors the serviceability of hand tools, the working surfaces of which must be even, and the wooden handles should be tightly fitted and wedged;

– works in mittens;

– performs jointing of external seams after each row in such a way as not to be on the wall;

– he performs cutting and cutting of bricks in goggles;

– encloses lined openings or inserts window or door blocks;

– masonry at the level of floors completes in the form of a ledge (side), rising 150 mm above the laid floor;

– when laying out the outer pilasters, when you have to stand on the wall, puts on a safety belt and is fixed to stable parts of the building.

Rice. 7.6. Measures to ensure masonry safety:a - fencing of openings;
b - arrangement of a side at the level of interfloor ceilings;in – work with a safety belt;1 - inventory fence;2 - side;3 - safety belt;4 – halyard fixed to the stable structures of the building

Upon completion of work the bricklayer removes tools, bricks, mortar residues from the wall, puts the workplace and passages in order. It is allowed to descend from scaffolding or scaffolding only along stepladders and capital mid-flight ladders (Fig. 7.7).

Rice. 7.7. Bricklayer's workplace after finishing work:

1 - stairs;2 – scaffolding

Rice. 7.8. Danger zone when applying solution
to the workplace of a bricklayer

All these requirements, together with the rational organization of labor and the workplace, with strict adherence to safety regulations, exclude cases of injury in the production of brickwork.

Labor protection instruction for masons

Bricklayers in the production of work on brickwork according to their qualifications, they are obliged to comply with the safety requirements set forth in " Model Instruction on labor protection for workers in construction, industry building materials and housing and communal services", of this model instruction, developed taking into account building codes and rules Russian Federation, as well as the requirements of manufacturers' instructions for the operation of technological equipment, equipment and tools used during operation.

It is necessary to comply with the safety requirements in accordance with SNiP 12-03-2001 and the rules for the production and acceptance of work in accordance with SNiP 3.03.01-87.

Before starting work on brickwork, masons must:

Present to the manager a certificate of knowledge of safe methods of working on brickwork;

Prepare the necessary funds personal protection, check them, put on a helmet, overalls, special. footwear of the established sample;

Prepare the necessary personal protective equipment, check them, receive an assignment for performing work on brickwork from a foreman or manager, and undergo a briefing at the workplace, taking into account the specifics of the work performed.

After receiving the assignment from the foreman or supervisor, the masons are required to:

Prepare the necessary personal protective equipment, check their serviceability;

Prepare technological equipment, tools necessary for performing work on brickwork, check their compliance with safety requirements.

Bricklayers should not start work on brickwork when:

Untimely conduct of regular tests ( technical inspection) technological equipment, tools and fixtures;

Untimely carrying out of the next tests or expiration of the service life of the protective equipment for workers, established by the manufacturer;

Insufficient illumination of workplaces and approaches to them;

Violation of the stability of structures of buildings and structures;

Detected violations of security requirements must be eliminated on your own, and if it is impossible to do this, the masons are obliged to report them to the foreman or the head of the brickwork.

When laying buildings, masons must:

Place bricks and mortar on ceilings or scaffolding in such a way that between them and the wall of the building there is a passage with a width of at least 0.6 m and overloading of the working floor is not allowed;

Use collective protection means (fences, trapping devices) or a safety belt with a safety rope when laying walls to a height of up to 0.7 m from the working platform, if the distance behind the wall under construction to the wall (ceiling) surface is more than 1.3 m;

To erect each subsequent floor of the building only after laying the floors above the erected floor;

Close voids in the slabs before they are delivered to the masonry site in the design position.

Bricklayers are obliged to fasten the safety belt in the places indicated by the work manager when laying:

Cornices, parapets, as well as alignment of corners, cleaning of facades, installation, dismantling and cleaning of protective peaks;

Walls of elevator shafts and other masonry work performed near unenclosed drops in height of 1.3 m or more;

Walls with a thickness of more than 0.75 m in the "standing" position on the wall.

Before laying the outer walls, masons must make sure that there are no people in the danger zone below, close to the place of work on the brickwork.

When moving and supplying bricks, ceramic stones and small blocks to the workplace by cranes, pallets, containers and lifting devices should be used to prevent the load from falling. Masons carrying out slinging of cargo must have a certificate of slingers and comply with the requirements of the "Standard instructions for labor protection for slingers".

In order to avoid the fall of pallets moved by a crane, freed from bricks, before they are slinged, it is necessary to tie them into packages.

When moving elements of prefabricated building structures (floor slabs, lintels, flights of stairs, platforms and other products) masons are required to be outside the danger zone that arose when moving goods with cranes. It is allowed to approach the specified elements only at a distance of not more than 0.5 m after they are lowered over the installation site to the design position.

During the acceptance of elements of prefabricated building structures, one should not be between the accepted elements of structures and the nearest edge of the outer wall.

Elements of prefabricated building structures should be installed without shocks and impacts on the mounted elements of building structures.

When performing work on punching furrows, fitting bricks and ceramic stones by chipping, masons are required to use safety glasses.

When supplying materials manually to the pits or to the underlying workplaces, masons are required to use inclined chutes with side boards. Materials lowered along the chute should be accepted after their descent has been stopped. Dropping materials from a height is not allowed.

When working with solutions with chemical additives, masons are required to use the protective equipment provided technological map to carry out the said work.

security requirements in emergency situations with brickwork

In the event of a failure of a pallet with a brick at the time of its movement by a crane, the masons must leave the danger zone and give a “Stop” signal to the crane operator. After that, the brick should be lowered to the ground and transferred to a serviceable pallet.

If cracks or displacement of the brickwork are found, work on the brickwork should be immediately stopped and the manager should be informed about this.

In the event of a soil landslide or violation of the integrity of the fastening of the slopes of the excavation, the masons are obliged to stop laying the foundation, leave the workplace and report the incident to the head of the brickwork.

Upon completion of work on brickwork, masons are required to:

Remove debris, waste materials and tools from the wall and scaffolding;

Clean the tool from the solution and put it in the place provided for storage;

Put in order and put away in the places intended for this place overalls, special footwear and personal protective equipment;

Notify the manager or foreman of any problems that have arisen during work.

4.7. Safety plastering works Oh:

When performing plastering work, one should strictly observe the safety rules, guided by the current regulatory and instructive documentation, including SNiP 12-04-2002 "Labor safety in construction. Part 2. Construction production", Chapter 10.

In addition, when performing plastering work, special attention must be paid to the following requirements:

Plastering work is allowed for persons who have been instructed in safety precautions, who have studied the devices, the principle and procedure for working with mechanisms and tools;

When performing plastering works with the use of mortar pumping units, it is necessary to provide two-way communication between the operator and the machine operator;

To dry the premises of buildings and structures under construction, if it is impossible to use heating systems, air heaters (electric or liquid fuel) should be used. When installing them, you must comply with the requirements of fire safety rules in the production of construction and installation works. It is forbidden to heat and dry the room with braziers and other devices that emit fuel combustion products into the room.

Before the start of each shift, check the serviceability of mortar pumps, dispenser hoses and other equipment used for plastering work. Gauges must be sealed.

It is forbidden to operate mortar pumps at a pressure exceeding that specified in the passport.

Operators inflicting plaster mortar to the surface with a nozzle, and the workers performing the spraying by hand are provided with goggles.

Portable current collectors (tools, machines, lamps, etc.) used in the performance of plastering work must have a voltage of not more than 36 V.

Scaffolding tools and other devices that ensure the safety of work performance must comply with the requirements of the "scaffolding tools".

Scaffolding means must have even working platforms with a gap between the boards of not more than 5 mm, and when the flooring is located at a height of 1.3 mm or more, fences and side elements. Lap joints of flooring panels are allowed only along their length, and the ends of the joined elements must be located on the support and overlap it by at least 0.2 m in each direction.

When accepting the scaffolding, the following should be checked: the presence of ties and fasteners that ensure stability, fasteners individual elements, working decks and fences, verticality of racks reliability support platforms and grounding (for metal scaffolding).

In places where people climb onto the scaffolding, there should be posters indicating the magnitude and layout of the loads.

Towers during operation should be inspected by a foreman or foreman at least every 10 days.

4.8. Safety precautions when working on the thermal insulation device:

Device work external thermal insulation buildings must be carried out taking into account the requirements of GOST 12.1.003 "SSBT. Noise. General requirements safety"; GOST 12.1.004 "SSBT. Fire safety. General requirements"; GOST 12.1.005 "SSBT. General sanitary and hygienic requirements for air working area"; GOST 12.1.019 "SSBT. Electrical safety. General requirements and nomenclature of types of protection"; "GOST 12.1.029 "SSBT. Means and methods of noise protection"; GOST 12.1.030. "SSBT. Electrical safety. Protective earth and zeroing"; GOST 12.2.003 "SSBT. Production equipment. General safety requirements"; GOST 12.2.010 "SSBT. Pneumatic manual machines. General safety requirements"; GOST 12.2.011 "SSBT. Construction and road machines. General safety requirements"; GOST 12.2.013.5 "SSBT. Machines manual electric. Particular safety requirements and test methods for circular saws and hacksaws"; GOST 12.2.013.6 "SSBT. Machines manual electric. Specific safety requirements and test methods for hammers and perforators"; GOST 12.2.013.0 "SSBT. Machines manual electric. General safety requirements and test methods"; GOST 12.2.030 "SSBT. Machines are manual. Noise characteristics. Norms. Control methods"; GOST 12.2.033 "SSBT. Workplaces when performing work while standing. General ergonomic requirements"; GOST 12.2.062 "SSBT. Production equipment. Protective fences"; GOST 12.2.071 "SSBT. Cranes are load-lifting. Container cranes"; GOST 12.3.009 "SSBT. Loading and unloading works. General safety requirements"; GOST 12.3.033 "SSBT. Construction vehicles. General safety requirements during operation"; GOST 12.3.038 "SSBT. Construction. Works on thermal insulation of equipment and pipelines. Safety requirements"; GOST 12.4.011 "SSBT. Means of protection for workers. General requirements and classification"; GOST 12.4.026 "SSBT. Signal colors and safety signs"; GOST 12.4.059 "SSBT. Construction. Inventory safety fences.

4.8. Safety precautions for painting work:

When performing work on surface finishing with paint compositions, it is necessary to comply with the rules provided for by SNiP 12-03-2001 "Labor safety in construction. Part 1. General requirements", "Instructions on fire safety for workers and engineering and technical workers of construction sites and enterprises of Glavmosstroy", GOST 12 1.004-91* "Fire safety", GOST 12.3.035-84 "Painting works".

Workers engaged in painting work should be trained in the techniques of work and safe methods labor.

Painting works at a height should be performed from scaffolding or cradles.

To work with pneumatic tools are allowed persons not younger than 18 years old, who have passed special education and who have received a certificate for the right to work with these tools, as well as certified for the first group of safety precautions and do not have medical contraindications for this species works. Every painter using a pneumatic painting tool must know the instructions and rules technical operation instrument, safe ways connecting and disconnecting the tool from the air duct; the main causes of tool failure and safe ways to fix them.

In the event of malfunctions in the operation of mechanisms necessary repairs it is allowed to produce only after they stop, de-energize and stop the supply of compressed air.

The housings of all electrical mechanisms must be reliably grounded.

Workers engaged in the production of painting work must be provided with the following individual and collective protective equipment in accordance with the requirements of GOST 12.4.011-89, which must be used depending on the nature of the work performed:

Safety shoes and overalls (GOST 12.4.103-83);

Rubber gloves (GOST 20010-93);

Cotton gloves (TU 17 RSFSR 06-7745-84);

For eye protection, goggles or goggles closed type;

For respiratory protection - anti-dust respirators RU-60MA, RPG-67A, ShB-1, "Petal" (GOST 12.4.028-76 * , GOST 17269-71 * , RU-6ONU (GOST 17269-71 * ).

The complex of sanitary and technical measures includes the provision of workers with amenity premises, sanitary and hygienic devices (SNiP 2.09.04-87*).

Workers employed in painting work must undergo an acceptance medical examination upon admission to work and periodic medical examinations by order of the Ministry of Health N 90 of 14.03.96.

In the process of application finishing materials it is possible to form a small amount of solid and liquid waste, they must be collected in special containers and sent for destruction in accordance with SN 3184-84 "Procedure for the accumulation, transportation, neutralization and disposal of toxic industrial waste." It is necessary to strictly observe the whole complex of measures for the protection environment. The product is disposed of in the same way after warranty period storage.

If paint or finishes come in contact with skin, remove with hand cleaner and rinse with water.

Solvent-based paints and solvents must be stored in closed, ventilated, explosion-proof rooms in accordance with the requirements of GOST 9980.5-86.

Safety in production is ensured with strict observance of the rules and methods of work. All tools and fixtures must be used in accordance with their intended use. Before work, make sure that the tools are in good order: they are correctly and firmly mounted on the handles, the working surfaces of the tools are even, without burrs; Damaged or deformed instruments must not be used. The bricklayer must work in gloves that protect the skin from abrasion. Brickwork is performed from the floors of inventory scaffolding or scaffolding. Scaffolding and scaffolding are installed on cleaned, leveled surfaces. Special attention make sure that the racks of the tubular scaffolding are correctly installed on the ground, the ground must be tightly packed. It is forbidden to install racks on the ground, not cleared of snow and ice. To evenly distribute the pressure under the racks, wooden linings are laid perpendicular to the wall being erected (one lining for two racks). Scaffolding and scaffolding must not be overloaded with materials in excess of the design load established for a given scaffolding or scaffolding design. The concentration of materials in one place should be avoided. Materials are stacked so that they do not interfere with the passage of workers and the transportation of materials. Between the stacks of materials and the wall, a working passage is left at least 60 cm wide.

Flooring from inventory boards sewn with planks on scaffolding and scaffolding must be even and without gaps. The gap between the wall of the building under construction and the working deck of the scaffold should not exceed 5 cm. This gap is needed so that, by lowering the plumb line below the scaffold, it is possible to check the verticality of the masonry being erected.

All decks of scaffolding and scaffolds with a height of more than 1.1 m, with the exception of scaffolds of continuous paving, are protected by railings with a height of at least 1.1 m, consisting of racks and attached to them with inside(at least three) horizontal elements: sideboard 150 mm high, installed close to the flooring, an intermediate element and an order. If the handrail is made of board, it needs to be cut off. The side board is placed in order to prevent any objects from falling from the scaffold. To lift workers on the scaffold, ladders with railings (handrails) are installed.

The state of scaffolding and scaffolding (connections, fastenings, flooring and fences) is systematically monitored. Every day after the end of work, the scaffolds are cleared of debris and before the start of the shift they are checked by the foreman in charge of the relevant work area at this facility and the foreman.

The brick is lifted to the floors (scaffolding, scaffolding), as a rule, in packages on pallets using cases that prevent the bricks from falling out. In containers and packages without pallets, it is allowed to lift bricks only with the help of grips that ensure safety (provided that devices enclosing the package are used). Devices for lifting bricks (cases, grips) must have devices that prevent spontaneous opening of these devices during lifting. It is forbidden to drop empty cases, grips, pallets from the floors; they are lowered with a crane.

The laying of any tier of walls is carried out so that its level after each relocation of the scaffold is 70 cm higher than the level of the working floor or floor. Below this level, masons work in safety belts, which are fastened to structures, or the perimeter of the masonry is fenced with protective nets.

Do not leave materials, tools, construction garbage, as they may fall on people below.

In the course of laying, window and door blocks or inventory fences are installed in the wall openings.

Cornices protruding beyond the plane of the wall by more than 30 cm are laid out from outdoor scaffolding or from inventory outlet scaffolds, the width of the flooring of which should be 60 cm more than the width of the cornice. In this case, the materials are placed on the internal decks, and the masons work while on the final scaffolding. When laying walls with a height of more than 7 m, external inventory protective visors are arranged around the entire perimeter of the building in the form of flooring on brackets (Fig. 76). Brackets 1 are hung on steel hooks J embedded in the masonry as it is erected. The width of the visor is not less than 1.5 m, outer corner lift 20°. When installing canopies, the following requirements are observed: the first row of canopies 4 is installed at a height of not more than 6 m from the ground and left until the masonry walls are erected to the full height; the second, made of solid or mesh materials with a cell of not more than 50X5 0 mm, - at a height of 6 ... 7 m above the first, and then rearrange along the masonry every 6 ... 7 m.

Workers mount protective visors in safety belts. It is forbidden to walk on the canopies, as well as use them as scaffolds and for stacking materials. Without protective canopies 4, it is possible to lay the walls of buildings with a height of no more than 7 m, but at the same time, fences are arranged on the ground along the perimeter of the building at a distance of at least 1.5 m from the wall.

When laying walls from internal scaffolds above the entrances to the stairwells, permanent canopies 5 (Fig. 76, b) are arranged with a size of at least 2X 2 m.

It is forbidden to lay out walls with a height of more than two floors without the installation of intermediate floors or temporary flooring along the beams of these floors, as well as without the device in stairwells platforms, marches and their temporary fences.

The seams are embroidered from the floors or from the scaffolds after laying each row. Do not stand on the wall during this operation.

Grouting and ironing of concrete surfaces

The water resistance of building envelopes can be increased to a large extent by grouting and lightly compacting the surface immediately after the concrete layer has been laid. Such plaster, being integral with the concrete masonry, will not flake off.

Concrete surfaces should be plastered with a mortar (in a ratio of 1: 1 or 1: 0.5) and rubbed with a steel spatula or trowel. In order for the plaster to crack less, it is necessary to add a small amount of lime paste containing 1 volume part of brand 300 cement, 0.5 parts of lime paste and 3 parts of sifted sand.

And to get iron plaster, you need to cover the freshly laid on horizontal surface cement mortar layer (2 mm) of dry clean cement, and then, as soon as it is saturated with water, smooth it with a steel trowel.

Such iron plaster has increased waterproofing properties.

Concrete curing and maintenance

The concrete mixture is laid at a temperature of 18–25 ° C, protecting it from impact and mechanical damage if possible. Freshly laid concrete is also protected from external influences: wind, frost and direct sunlight.

Freshly laid concrete mix cover with burlap or a thick cloth and pour water over it.

If a concrete works held in winter time, check the strength of concrete in advance (before freezing). It should be:

– 50% for concrete and reinforced concrete structures with concrete grade 150;

- 30% for concrete grades 400-500;

- 70% for superstructures.

At negative temperatures, concrete is cured using the "thermos" method. For this, insulated formwork is made, and open surfaces are covered protective coating, usually sawdust.

If the air temperature is too low, the thermos method is combined with electric heating concrete, blowing warm air or ferry.

When laying concrete at low negative temperatures, chemical additives are added to it: calcium chloride, sodium chloride, potash, sodium nitrite.

Do not use chemical additives:

- in reinforced concrete structures located near a high voltage direct current source;

- in parts of structures located on the ground with a variable water level;

- in structures subjected to dynamic loads;

- in the construction of monolithic chimneys.

In construction, there are two ways to test the strength of hardened concrete: destructive and non-destructive.

In the first case, when laying concrete, a part of the concrete is left, from which cubes of 15 x 15 x 15 cm in size are made and kept in the same conditions as the bulk of the concrete.

In the second case, the strength of hardened concrete is checked by an ultrasonic method or using a Kashkarov hammer. The depth of the hole left when a hammer strikes concrete indicates the strength of the concrete.

Formwork

AT modern construction There are many ways to perform concrete work with high quality, least cost labor and in short time. The most famous of them are inventory formwork. According to the type of construction, they are divided into:

- stationary;

- collapsible;

- suspended;

- sliding;

– special block forms. The type of formwork for concrete and reinforced concrete structures depends on their size and configuration.

formwork type

1. Collapsible small-panel formwork can be:

- inventory, used for concreting monolithic structures;

- unified, non-unified - for concreting structures of small volume;

- non-inventory - for single non-standard buildings.

2. Collapsible-adjustable large-panel board, used for large-sized wall structures.

3. Climbing - for chimneys.

4. Horizontally sliding - for retaining walls. collectors and other open structures.

5. Tunnel - for concreting monolithic finish tunnels built in a closed way.

6. Block-form - for stepped foundations.

7. Volumetric adjustable - for concreting buildings with transverse bearing walls and monolithic ceilings.

8. Sliding - for the construction of buildings with a height of more than 15 m.

9. Pneumatic - for the construction of curved structures.

10. Fixed - for cladding, insulation and waterproofing of thermal insulation of structures.

For the manufacture of formwork, lumber is used from conifers. To reduce the adhesion of formwork to concrete, it is recommended to cover the front surface of the installed formwork with a lubricant ( milk of lime, a solution of liquid clay, used mineral oils, etc.).

Reinforcing works

The quality of reinforced concrete and its load bearing capacity depends on proper styling reinforcing bars. In structures pinched on one side, reinforcement is placed at the top of the concrete. If the structure is grounded on both sides, the reinforcing bars are located in the lower layers. In this case, the reinforcement should be located in the thickness of the concrete mass, in the middle, at least 5 cm from the edges. If you choose the right binders, aggregates and reinforcement, it will turn out strong building construction capable of withstanding heavy loads. For the manufacture of reinforcing cages, round steel is used, the diameter of which is usually indicated in the project. Make your own reinforcing cages impossible, they are made mainly in factories.

6. Safety regulations

As you know, a person is in danger everywhere and everywhere you need to be careful and adhere to certain safety rules. This also applies construction works. Modern methods construction require special knowledge of safe work practices.

Safety regulations for the production of stone works

Industrial injuries during stone work can be caused by the following:

- collapse of walls due to improper masonry;

– weakening of cementing solutions;

- falling bricks from a height onto workers in the danger zone;

- overloading of scaffolds with building materials;

- people falling from a height in the absence of special protective devices.

Injuries are sometimes caused by improper organization of work and imperfect technology.

Some mortars and materials, such as lime or cement, are harmful to human respiratory organs and skin, sometimes causing chemical burns. This can happen when unloading lime manually without using the necessary protective equipment.

When transporting dry building materials, dust masks and goggles should be worn.

When preparing lime dough, the following, very common mistake is made: lime is diluted in a specially dug hole, not fenced in any way and not covered with a lid. It is forbidden to unload the dough from the trough by hand.

When repairing foundations, they are replaced or supplied without significant interruptions in work in separate non-adjacent sections with a length of not more than 1 m.

The walls are pre-strengthened, in case of cracks, beacons are placed on them, which are constantly monitored.

in windows and doorways on the first floor, temporary fastenings of the jumpers are installed, and in the pit around the house - a temporary strong fastening of the remaining part of the foundation.

Places of production of work on laying the foundation are fenced at least 1.4 m from the wall.

On the construction site must have a first aid kit first aid. It includes bandages, sterile cotton, adhesive plaster, rubber tourniquet, iodine, brilliant green solution, ammonia, a remedy for burns.