STATE COMMITTEE OF THE USSR COUNCIL OF MINISTERS FOR CONSTRUCTION

GOSSTROY USSR

BUILDING REGULATIONS

RULES FOR PRODUCTION AND ACCEPTANCE OF WORK

Concrete and reinforced concrete

monolithic structures

8aianeh si and Lz.sz onhowiss

POTLDVO P0CH.12M

EST 3-SSe.Vy-irJ

Moscow 1977

Official publication

STATE COMMITTEE OF THE USSR COUNCIL OF MINISTERS FOR CONSTRUCTION (GOSSTROY USSR)

MOSCOW STROYIZDAT 1977

UDC 693.54(063.73)

Chapter SNiP III-15-76 “Concrete and reinforced concrete monolithic structures” was developed by the 1DNIIOMTP Institute of the USSR State Construction Committee with the participation of NIIZhB, Donetsk Promstroyniproekt, Krasnoyarsk Industrial Construction Project of the USSR Gosstroy, Gorky Civil Engineering Institute named after. Chkalov Ministry of Higher Education of the RSFSR, VNIIG im. Vedeneev and Orgenergostroy of the USSR Ministry of Energy, Lenmoriiiproekt of the USSR Ministry of Marine Fleet, TsNIIS of the USSR Ministry of Transport. With the entry into force of this chapter, Chapter SNiP III-B.1-70 “Concrete and reinforced concrete monolithic structures” becomes invalid. Rules for the production and acceptance of work" and "Instructions for the use of concrete with the addition of sulfite-yeast mash concentrates" (SN 406-70).

Editors - engineers A. I. Davydov, A. A. Lysogorsky (Gosstroy USSR), Ph.D. tech. Sciences B.I. Berezovsky, Doctor of Engineering. Sciences N. E. Nosenko, Ph.D. tech. Sciences V. D. Topchiy (TsNIIOMTP Gosstroy USSR), Doctor of Engineering. Sciences B. A. Krylov (NIIZhB Gosstroy USSR).

S VPSh-tG Inst No. """"’« t * 11 »“" “

© Stroyizdat, 1977

State Committee of Omet of Ministers of the USSR for Construction Affairs (Gosstroy USSR)

1. GENERAL PROVISIONS

1.1. The rules of this chapter must be observed when constructing monolithic concrete and reinforced concrete structures, monolithic parts and prefabricated joints monolithic structures from heavy, especially heavy, porous aggregates, heat-resistant, acid-resistant and alkali-resistant concrete, during shotcrete and underwater concreting work, as well as during the manufacture of prefabricated concrete and reinforced concrete structures on a construction site.

1.2. When erecting concrete and reinforced concrete structures, in addition to complying with the rules of this chapter, the requirements of the relevant state standards, heads of SNiP: on the organization of construction, safety precautions in construction and on the construction of special structures (bridges, airfields, hydraulic engineering, etc.), as well as rules fire safety during construction and installation works and instructions for the development of construction organization projects and work execution projects.

1.3. Materials used in the construction of concrete and reinforced concrete structures, their order

acceptance, testing, as well as their transportation and storage, must meet the requirements of relevant standards and technical specifications.

1.4. When developing technology for the construction of concrete and reinforced concrete structures, the following should be provided: comprehensive mechanization production processes, the primary use of inventory reversible formwork, the use of enlarged volumetric and flat reinforcing products, the use of ready-mix concrete mixtures prepared in automated concrete mixing plants, and also take into account the properties of concrete in terms of strength, density, frost resistance, uniformity and its structure and other requirements provided for by the project .

2. FORMWORK

General requirements

2.1. When constructing formwork, the following requirements must be observed:

the formwork must have the necessary strength, rigidity and immutability under the influence of technological loads (loads and data for formwork calculations are given in Appendix 1) and low adhesion to concrete;

must ensure the specified accuracy of the dimensions of structures, as well as the correct position of the structure in space. The design of the formwork must ensure that it can be quick installation and disassembly without damaging the concrete;

do not interfere with the convenience of installing reinforcement, laying and compacting the concrete mixture. When assembling the formwork, the required density in the joints must be ensured individual elements;

compensators will be provided to reduce temperature stresses when the concrete is heated. The formwork design must allow reassembly during the construction process.

As a rule, standardized standards should be used standard systems formworks with modular resizing. For the assembly of formwork forms of non-standard structures and structures (including those with curved surfaces of the second and third order of curvature, with a complex configuration in plan, etc.), it is allowed to use stationary (non-reversible) formwork made of various materials, manufactured and installed on site.

2.2. The installation of formwork must be carried out according to the work plan.

2.3. Tie bolts and tie rods, as well as fastening elements, must be in stock and can be quickly installed and removed. Non-inventory ties and twists can be used when constructing formwork for individual small-volume structures.

2.4. The use of suspended formwork attached to rigid reinforcement or to reinforcement cages, which absorb the pressure of the mass of the concrete mixture and production loads, is allowed only in cases where such formwork is provided for by the construction design.

2.5. Dimensions of formwork and stops at. in the manufacture of prestressed reinforced concrete structures should be assigned taking into account deformations due to compression forces.

2.6. Using formwork in winter conditions the possibility of insulating it or installing heating elements in it should be provided.

2.7. The choice of formwork is determined by the type and size of the structures to be concreted and the method of production of reinforcement and concrete works. The characteristics of the main types of formwork and their scope of application are given in table. 1.

Tavlzhaa 1

Formwork	Characteristics* of formwork	Prktyasaka area
1. Raeborn-rearranged small-shield: a) inventory unified	It consists of a set of small elements weighing no more than 50 kg and shields with an area of ​​about 1 m*. load-bearing elements (clasps, stiffening elements), supporting formwork elements of horizontal and inclined surfaces, fastening and connecting elements, allows tiered rearrangement with a minimum number of additional elements, and	For concreting various types of monolithic structures, including curved ones
b) non-unified		For concreting small-volume structures with repeated formwork turnover until worn out
c) non-inventory	also assembly of enlarged elements, assembly of enlarged panels and spatial blocks	For single non-standard structures that do not have repeating elements
2. Collapsible	Consists of large-sized shields.	For large-sized massive
I'm big-faced	connection and fastening elements. Formwork panels absorb all technological loads without installing additional load-bearing or supporting elements and include a deck, stiffeners and load-bearing elements. It is equipped with scaffolding, struts, adjusting and installation jacks, allows the installation of tiers of the next highest height after dismantling the lower ones	structures, walls (including curved ones)

3. Lifting mechanism	Consists of panels, fasteners, lifting devices, a system for controlling the movement of formwork and monitoring the accuracy of movement and horizontal floor level, allows for changes in the transverse structure being concreted when moving the formwork in height	For structures and structures of variable cross-section ( chimneys, cooling towers, etc.)
4. Horizontal sliding (rolling)	It consists of a frame and formwork panels attached to it (movably or stationarily), a mechanism for moving horizontally and vertically, a control system and monitoring the accuracy of movement during the concreting process, it can be changed cross section structure and the radius of its curvature, has a taper" within Vjoco of the length of the formwork panels	For long-term structures, including curved ones (retaining walls, tunnels, collectors, water conduits and other structures erected open method)
5. Tunnel	Consists of forming and supporting sections and moves using special mechanisms with mechanical, hydraulic and other drives	For concreting the monolithic lining of tunnels constructed in a closed way
6. Block shape		For free-standing closed-loop structures or their parts with a volume of up to 25-$0 m 5 (columns, grillages, stepped foundations, etc.)

SNiP 111-15-76

Continued table. 1

Jumbo	Characteristics of formwork	Application area
7. Individual flea forms: a) one-piece	Represent spatial frame structure, consisting of 4 or 8 sashes with a taper Vie of sashes height. total area surface 6-10 m* They are a spatial frame structure consisting of 4-12 sashes. The doors are united by a frame on each side and have connecting devices in the corners. Before dismantling, the sashes are separated from the concrete using pressing devices. Total surface area 8-10 m*	For concreting similar structures of small volume up to 5 m 3 with stripping at an early age (no later than 24 hours)
b) detachable		For concreting similar structures with a volume of up to 15 m 3
8. Reconfigurable block forms	They allow changes in the dimensions in plan and height of both individual sashes and the entire flea shape due to the inventory inserts of frame elements on the sashes. They have squeezing devices for preliminary separation of the gates from the concrete during dismantling. Surface area 8-40 m 1	For concreting structures that differ in linear dimensions, maximum dimensions and configuration
9. Volume-adjustable	Consists of vertical and horizontal sashes, hinged	For the construction of residential and civil buildings with transverse load-bearing

SNiP 111-15-76

	on a shaped frame, which when connected along the length form tunnels. A system of tunnels installed parallel and perpendicular to each other forms a form for concreting walls and ceilings. When stripping the formwork, the sashes are separated from the concrete	walls and monolithic coatings
10. Sliding	Consists of panels mounted on jacking frames, a working floor, jacks, pumping stations and other elements. The entire system is periodically lifted with jacks as concreting proceeds, allowing taper within the limits of the height of the panels	For the construction of vertical buildings and structures more than 15 m high
11. Pneumatic	It consists of a flexible airtight shell, cut in accordance with the outline of the structure. Installation into the working position is carried out by creating inside the shell overpressure air. Pneumatic cylinders can be used as supporting and load-bearing elements	For structures with a curved outline
12. Fixed	Remaining in the structure after concreting, as well as blocks and shells that are firmly connected to the main structure during concreting	For the manufacture of structures without stripping, for cladding, waterproofing or thermal insulation of structures, as well as in other cases with an appropriate feasibility study

SNiP 111-15-76

Formwork materials

2.8. Load-bearing elements inventory formwork, its fastening parts and structures supporting the formwork should be made from materials specified in the project, observing the requirements technical rules on the economical use of basic building materials.

2.9. Formwork elements (panels) in contact with concrete should be made primarily of waterproof plywood. The use of lumber is allowed for the manufacture of additional elements and inventory panels with a turnover of no more than 10 times.

2.10. The following requirements apply to timber and materials made from wood and used for formwork and its supporting structures:

posts with a height of more than 3 m, purlins supporting formwork and deck elements in contact with concrete must be made only of wood coniferous species not lower than grade III. For bending elements, lumber of at least grade II must be used. For other elements of formwork and fastenings, hardwood (aspen, alder) can be used. Birch should not be used for decks;

inventory elements of formwork and scaffolding (column clamps, inventory racks, etc.) must be made from grade II lumber;

for the manufacture of load-bearing frames, coniferous wood with a moisture content of no more than 15% should be used, for other elements - with a moisture content of no more than 25%;

formwork boards directly adjacent to the concrete must be planed and have a width of no more than 150 mm. Boards used in sliding formwork for cladding should be no wider than 120 mm;

plywood used to make formwork must be waterproof. Working and end surfaces plywood board must be protected

waterproof coating i.e. polymer materials, laminated plastic, fiberglass.

Particle boards and fibreboards used for the manufacture of inventory formwork must be hydrophobic or have protective covering from synthetic materials.

2.11. Metal mesh used for permanent formwork, must have cells no larger than 5x5 mm. Before installation and concreting, the mesh must be degreased.

2.12. Concrete and reinforced concrete formwork, as well as other materials included in the erected structure for formwork elements (ceramics, glass, asbestos cement, etc.) must meet the requirements for the structures being erected.

Materials for glass-cement shell slabs, which act as formwork for monolithic structures and operate in aggressive environments, must meet the requirements for waterproofing and chemical resistant coatings.

2.13. Electric heaters thermosetting formwork must be standard, mass-produced, closed type. For one or two-time use, it is allowed to use non-standard heaters, which must meet the requirements of vibration resistance, electrical strength and fire safety.

2.14. The insulation of thermoactive formwork must be fireproof, have a low volumetric mass, as well as sufficient mechanical stability and a low thermal conductivity coefficient that does not change during the period of use in the formwork.

Acceptance of formwork elements

2.15. All elements of inventory formwork must arrive marked from manufacturers. Visual quality control of formwork on

table 2

Formwork elements	Permissible deviations of formwork, mm
	wooden and plywood	metal and wood-metallic
1. Collapsible formwork panels and frames for them in length or width:
b) more than 1 m
c) diagonally
d) deviations of the edges of the shields from straight
my line or line forming the surface of structures 2. Block forms: deviations from the design dimensions in plan: a) individual one-piece
b) rachRemovable
c) reconfigurable
difference in length of diagonals:
a) individual one-piece
b) detachable
c) reconfigurable
3. Volumetric, sliding and rolling: a) deviations from the design dimensions
b) the difference in the length of the diagonals in plan
c) difference between adjacent panels
when joining sections 4. Displacements from the design position
holes for connecting elements (bolts, tension hooks, spring clips, etc.) 5. Deflection of the sashes: from the work plane
in the working plane
6. Local unevenness of surfaces in contact with concrete: a) one-piece
b) detachable and reconfigurable

construction site should be done before assembly. Periodic instrumental inspection should be carried out: steel elements - at least every 20 revolutions; wood elements - after 5 turns. Deviations from the design dimensions of the formwork should not exceed the values ​​​​given in table. 2.

2.16. Before assembling thermoactive formwork, the condition of the insulation, the outer protective cover, the fastening of electrical connectors, and the presence of a designation of the formwork characteristics on the insulation cover: design heat transfer coefficient, power density heaters and operating voltage. During operation - electrical characteristics, including electrical insulation resistance, must be checked at least once after 5 turns of the formwork.

2.17. The arrangement of electric heaters and insulation in thermoactive formwork panels should ensure a uniform temperature field on the plane with a temperature difference at its individual points of no more than 5 ° C.

The design of the formwork insulation must ensure thermal insulation of the intermediate stiffening ribs of the formwork panels and eliminate heat loss.

2.18. Steel surfaces of formwork elements and supporting structures that are not in contact with concrete must be painted with weather-resistant paints.

Transportation and storage of formwork

2.19. Transportation of inventory formwork elements must be carried out according to the project. In the absence of special requirements for transportation, the conditions set out in table must be observed. 3.

2.20. All elements of inventory formwork must be stored in a position corresponding to transport, sorted by brand and standard size. Hinge joints and threaded elements must be coated with anti-corrosion lubricants.

	Table 3
Elements	Transportation conditions
1. Panels made of steel, plastic, plywood and wood derivatives	In a vertical position in one tier, in a horizontal position in 10-15 tiers with a total height of no more than 1.5 m
2. Panels of permanent formwork and thermoactive steel	In a horizontal position in 7-10 tiers with a total height of no more than 1.5 m with installation wooden spacers between each tier there are 10 mm more protruding anchors or electrical connectors
3. Steel or wooden contractions	Horizontally in 5-10 tiers with a total height of no more than 1 m with the installation of wooden spacers between the tiers
4 Sliding crossbars, working floor trusses of sliding formwork, supporting* suspended scaffold structures	In a position corresponding to the worker, no more than 2 tiers with protection from tipping over
5. House multiple frames	Upright
6. Telescopic stands	In vertical or horizontal position on spacers
7. Block molds: one-piece	In the position corresponding to the working
detachable and reconfigurable	Separate elements with the wings supported on a vehicle or on special scaffolding
$. Volume-adjustable, rolling and tunnel formwork	Assembled or disassembled in a horizontal position in 3-5 tiers on spacers made of wooden beams

Thermoactive shields must be stored under canopies or shelters made of moisture-proof materials on areas that prevent them from getting wet.

2.21. Woven metal grid and tissue ma-. Pneumatic formwork materials must be stored under canopies in rolls under conditions that prevent cracks and other damage from occurring on the fabric.

2.22. Volume-adjustable, rolling and tunnel formwork can be stored in working position. Horizontal working planes must be coated with anti-corrosion lubricants and moisture-proof materials (polyethylene films, roofing felt, etc.).

Installation and acceptance of formwork

2.23. The assembly of formwork forms from elements of inventory formwork, as well as the installation of volumetric-adjustable, sliding, tunnel and rolling formwork into the working position must be carried out in accordance with technological rules for their assembly.

The forming surfaces of the formwork must be lubricated with anti-adhesive grease.

2.24. When installing structures supporting formwork, the following requirements must be met:

the racks must be installed on foundations that have a supporting area sufficient to protect the concreted structure from unacceptable subsidence;

ties, screeds and other fastening elements should not interfere with concreting;

fastening of ties and braces to previously concreted structures should be carried out taking into account the strength of the concrete at the moment the loads from these fastenings are transferred to it;

the base for the formwork must be leveled before installation.

2.25. Formwork and rounding of reinforced concrete arches and vaults, as well as formwork reinforced concrete beams

with a span of more than 4 m must be installed with a construction lift.

The outline of the construction rise circles and the formwork of arches and vaults must be installed in accordance with the project. The amount of construction lift must be at least 5 mm per 1 m span of arches and vaults, and for beam structures - at least 3 mm per 1 m span.

2.26. When accepting the installed formwork, its supporting structures and fastenings, the following must be checked:

load-bearing foundations supporting the formwork of the structure and the formwork itself;

the rigidity and immutability of the entire system as a whole and the correct installation of structures supporting the formwork;

correct installation of formwork, plugs and embedded parts;

the density of the formwork panels and the joints connecting the formwork elements with each other and with previously laid concrete;

formwork surfaces and their position relative to the design axes of structures to be concreted.

2.27. Permissible deviations of the positions and dimensions of the installed formwork and supporting scaffolding from the design should not exceed those indicated in table. 4.

The formwork assembled and prepared for concreting, as well as equipment for lifting it, must be accepted according to the act.

The condition of the installed formwork, scaffolding and fastenings must be continuously monitored during the concreting process. Checking the correct position of the axes of volumetrically adjustable and horizontally moving (rolling) formworks should be carried out after each rearrangement. If deformation or displacement of individual elements of the formwork, scaffolding and fastenings is detected, measures must be taken immediately to eliminate the deformations and, if necessary, concreting work in this area must be temporarily stopped.

Table 4

Elements of formwork structures	Permissible deviations, mm
1. Distance between bending supports
formwork elements and the distance between the connections
links of vertical supporting structures
tions from design dimensions:
per 1 m length
for the entire span, no more
2. Distance from vertical or design
inclination of the formwork planes and lines of their re-
at 1 m height
full height:
foundations
walls and columns up to 5 m high
walls and columns more than 5 m high
beams and arches
3. Displacement of the formwork axes from the design
provisions:
foundations
walls and columns
beams, purlins, arches
foundations for steel structures
	(L - length of pro-
	summer or step
	structures, m)
4. The largest difference in plane elevations
upper circles or working floor surfaces
sliding formwork at a distance:
from 3 m or more
5. Position of jack frames and axles	Not allowed
jacks from vertical
6. The greatest difference in the marks of the crossbars
same type house multiple frames
7. “Taper” of sliding formwork by one
8. Reverse “taper”	Not allowed
9. Distance between jacks, frames (beyond
with the exception of places where the distance between the frames
is free size)
10. Displacement of the jack axes from the axis of the const.
11. Displacement of the axes of the moved or re-
the formwork being installed relative to the axes coop y-

Continued table 4

Stripping structures

2.28. When uncircling and dismantling structures supporting the formwork of vaults, arches, bunkers and other complex structures, as well as beam structures with a span of more than 8 m, the following requirements must be met:

the removal of supports should be preceded by untwisting of the structures (i.e., lowering of these supports);

unwinding should be carried out in several stages using means that ensure smooth lowering of the structures supporting the formwork;

the order of turning, the amount of lowering of supports supporting the formwork of structures, and other conditions of turning must correspond to those specified in the project;

before unwinding arches with strings, the strings must be tensioned;

stripping dome coverings, as well as bunker funnels, should start from the racks located in the center of the structure and lead in concentric rows towards its perimeter.

2.29. Tear-off from concrete and detachment of internal formwork and outer contour panels in the absence of assembly scaffolds should be carried out after temporary fastening of the formwork to supporting structures or a lifting mechanism.

2.30. Severing from the concrete and lowering large-panel floor formwork (when dismantling in a block without a bulkhead) should be carried out with uniform, alternate operation of all support jacks

in order to eliminate the possibility of jamming and distortions.

2.31. Dismantling of sliding formwork should be carried out in large blocks in accordance with the work project.

2.32. The formwork and equipment must be disassembled in an order in which, after separating parts of the formwork and equipment, the stability and safety of the remaining elements is ensured.

2.33. Dismantling of thermoactive formwork should be carried out after disconnecting all panels from the electrical supply and removing the switching wiring from the working area.

3. REINFORCEMENT WORK General requirements

3.1. Reinforcement of reinforced concrete structures should be carried out with enlarged welded reinforcement frames and prefabricated meshes. Manufacturing of reinforcement directly on the construction site and reinforcement with piece rods is allowed for additional parts of reinforcement or for connection areas between meshes (frames).

3.2. Replacement of reinforcing steel provided by the project by class, grade, range or replacement of anchor design must be agreed with design organization.

3.3. Upon acceptance, reinforcing steel, embedded parts and anchors supplied for construction must be subject to external inspection and measurements, as well as control tests in the following cases:

specified in the project or special instructions for the use of certain types of reinforcing steel;

doubts about the correctness of the characteristics of reinforcing steel, embedded parts and anchors, as well as the lack of necessary data in the certificates of manufacturers;

use of reinforcement as prestressed reinforcement.

Selection procedure, test methods and number of controls

STATE COMMITTEE OF THE USSR COUNCIL OF MINISTERS FOR CONSTRUCTION

GOSSTROY USSR

SNiP

111-15-76

BUILDING REGULATIONS

Part III

RULES FOR PRODUCTION AND ACCEPTANCE OF WORK

Official publication

STATE COMMITTEE OF THE USSR COUNCIL OF MINISTERS FOR CONSTRUCTION (GOSSTROY USSR)

MOSCOW STROYIZDAT 1977

Formwork materials

2.8. The load-bearing elements of the inventory formwork, its fastening parts and the structures supporting the formwork should be made from materials specified in the project, observing the requirements of technical rules for the economical use of basic building materials.

2.9. Formwork elements (panels) in contact with concrete should be made primarily of waterproof plywood. The use of lumber is allowed for the manufacture of additional elements and inventory panels with a turnover of no more than 10 times.

2.10. The following requirements apply to timber and materials made from wood and used for formwork and its supporting structures:

posts with a height of more than 3 m, purlins supporting the formwork and deck elements in contact with concrete must be made only from coniferous wood of at least grade III. For bending elements, lumber of at least grade II must be used. For other elements of formwork and fastenings, hardwood (aspen, alder) can be used. Birch should not be used for decks;

inventory elements of formwork and scaffolding (column clamps, inventory racks, etc.) must be made from grade II lumber;

for the manufacture of load-bearing frames, coniferous wood with a moisture content of no more than 15% should be used, for other elements - with a moisture content of no more than 25%;

formwork boards directly adjacent to the concrete must be planed and have a width of no more than 150 mm. Boards used in sliding formwork for cladding should be no wider than 120 mm;

plywood used to make formwork must be waterproof. The working and end surfaces of the plywood board must be protected

waterproof coating made of polymer materials, laminated paper, fiberglass.

Particle boards and fibreboards used for the manufacture of inventory formwork must be hydrophobic or have a protective coating made of synthetic materials.

2.11. The metal mesh used for permanent formwork must have cells measuring no more than 5x5 mm. Before installation and concreting, the mesh must be degreased.

2.12. Concrete and reinforced concrete formwork, as well as other materials included in the erected structure for formwork elements (ceramics, glass, asbestos cement, etc.) must meet the requirements for the structures being erected.

Materials for glass-cement shell slabs, which act as formwork for monolithic structures and operate in aggressive environments, must meet the requirements for waterproofing and chemically resistant coatings.

2.13. Electric heaters for thermoactive formwork must be standard, mass-produced, closed type. For one or two-time use, it is allowed to use non-standard heaters, which must meet the requirements of vibration resistance, electrical strength and fire safety.

2.14. The insulation of thermoactive formwork must be fireproof, have a low volumetric mass, as well as sufficient mechanical stability and a low thermal conductivity coefficient that does not change during the period of use in the formwork.

Acceptance of formwork elements

2.15. All elements of inventory formwork must arrive marked from manufacturers. Visual quality control of formwork on

table 2

Formwork elements Permissible deviations of formwork, mm wooden and plywood metal and wood-metal 1. Collapsible formwork panels and frames for them in length or width: b) more than 1 m c) diagonally d) deviations of the edges of the boards from a straight line or a line forming the surface of structures 2. Block forms: deviations from the design dimensions in plan: a) individual one-piece b) detachable c) reconfigurable difference in length of diagonals: a) individual one-piece 6) detachable c) adjustable 3. Volumetric, sliding and rolling: a) deviations from the design dimensions of the boards b) the difference in the length of the diagonals in plan c) the difference between adjacent panels when joining sections 4. Displacements from the design position of holes for connecting elements (bolts, tension hooks, spring clips, etc.) 5. Deflection of the sashes: from the work plane in the working plane 6. Local unevenness of surfaces in contact with concrete: a) one-piece b) detachable and reconfigurable

construction site should be carried out prior to assembly. Periodic instrumental inspection should be carried out: steel elements - at least every 20 revolutions; wood elements - after 5 turns. Deviations from the design dimensions of the formwork should not exceed the values ​​​​given in table. 2.

2.16. Before assembling thermoactive formwork, the condition of the insulation, the outer protective cover, the fastening of electrical connectors, and the presence on the insulation cover of the designation of the formwork characteristics: design heat transfer coefficient, specific power of heaters and operating voltage must be checked. During operation, electrical characteristics, including electrical insulation resistance, must be monitored at least once after 5 rotations of the formwork.

2.17. The arrangement of electric heaters and insulation in thermoactive formwork panels should ensure a uniform temperature field on the plane with a temperature difference at its individual points of no more than 5 ° C.

The design of the formwork insulation must ensure thermal insulation of the intermediate stiffening ribs of the formwork panels and eliminate heat loss.

2.18. Steel surfaces of formwork elements and supporting structures that are not in contact with concrete must be painted with weather-resistant paints.

Transportation and storage of formwork

2.19. Transportation of inventory formwork elements must be carried out according to the project. In the absence of special requirements for transportation, the conditions set out in table must be observed. 3.

2.20. All elements of inventory formwork must be stored in a position corresponding to transport, sorted by brand and standard size. Hinge joints and threaded elements must be coated with anti-corrosion lubricants.

Table 3

Elements Transportation conditions 1. Panels made of steel, plastic, plywood and wood derivatives In a vertical position in one tier, in a horizontal position in 10-15 tiers with a total height of no more than 1.5 m 2. Panels of permanent formwork and thermoactive steel In a horizontal position in 7-10 tiers with a total height of no more than 1.5 m with the installation of wooden spacers between each tier with 10 mm more protruding anchors or electrical connectors 3. Steel or wooden contractions Horizontally in 5-10 tiers with a total height of no more than 1 m with the installation of wooden spacers between the tiers 4 Sliding crossbars, . working floor trusses of sliding formwork supporting suspended scaffold structures In positions corresponding to the worker, no more than 2 tiers with security against tipping 5, Jacking frames Upright 6. Telescopic stands In vertical or horizontal position on spacers 7. Block molds: one-piece In the position corresponding to the working detachable and reconfigurable Separate elements with the wings supported on a vehicle or on special scaffolding 8. Volume-adjustable, rolling and tunnel formwork Assembled or disassembled in a horizontal position in 3-5 tiers on spacers made of wooden beams

Thermoactive shields should be stored under canopies or shelters made of moisture-proof materials on areas that prevent them from getting wet.

2.21. Woven metal mesh and fabric materials for pneumatic formwork must be stored under canopies in rolls under conditions that prevent cracks and other damage to the fabric*

2.22. Volume-adjustable, rolling and tunnel formwork can be stored in working position. Horizontal working planes must be coated with anti-corrosion lubricants and moisture-proof materials (polyethylene films, roofing felt, etc.).

Installation and acceptance of formwork

2.23. The assembly of formwork forms from elements of inventory formwork, as well as the installation of volumetric-adjustable, sliding, tunnel and rolling formwork into the working position must be carried out in accordance with the technological rules for their assembly.

The forming surfaces of the formwork must be lubricated with anti-adhesive grease.

2.24. When installing structures supporting the formwork, the following requirements must be met:

the racks must be installed on foundations that have a supporting area sufficient to protect the concreted structure from unacceptable subsidence;

ties, screeds and other fastening elements should not interfere with concreting;

fastening of ties and braces to previously concreted structures should be carried out taking into account the strength of the concrete at the time the Loads from these fastenings are transferred to it;

the base for the formwork must be leveled before installation.

2.25. Formwork and rounding of reinforced concrete arches and vaults, as well as formwork of reinforced concrete beams

with a span of more than 4 m must be installed with a construction lift.

The outline of the construction rise circles and the formwork of arches and vaults must be installed in accordance with the project. The amount of construction lift must be at least 5 mm per 1 m span of arches and vaults, and for beam structures - at least 3 mm per 1 m span.

2.26. When accepting the installed formwork, its supporting structures and fastenings, the following must be checked:

load-bearing foundations supporting the formwork of the structure and the formwork itself;

the rigidity and immutability of the entire system as a whole and the correct installation of structures supporting the formwork;

correct installation of formwork, plugs and embedded parts;

the density of the formwork panels and the joints connecting the formwork elements with each other and with previously laid concrete;

formwork surfaces and their position relative to the design axes of structures to be concreted.

2.27. Permissible deviations of the positions and dimensions of the installed formwork and supporting scaffolding from the design should not exceed those indicated in table. 4.

The formwork assembled and prepared for concreting, as well as equipment for lifting it, must be accepted according to the act.

The condition of the installed formwork, scaffolding and fastenings must be continuously monitored during the concreting process. Checking the correct position of the axes of volumetrically adjustable and horizontally moving (rolling) formworks should be carried out after each rearrangement. If deformation or displacement of individual elements of the formwork, scaffolding and fastenings is detected, measures must be taken immediately to eliminate the deformations and, if necessary, concreting work in this area must be temporarily stopped.

Table 4

Elements of formwork structures Permissible deviations, mm 1. Distance between bending supports formwork elements and the distance between the connections links of vertical supporting structures tions from design dimensions: per 1 m length for the entire span, no more 2. Distance from vertical or design inclination of the formwork planes and lines of their re- at 1 m height full height: foundations walls and columns up to 5 m high walls and columns more than 5 m high beams and arches 3. Displacement of the formwork axes from the design provisions: foundations walls and columns beams, purlins, arches foundations for steel structures (L is the length of the summer or step structures, m) 4. The largest difference in plane elevations upper circles or working floor surfaces sliding formwork at a distance: from 3 m or more 5. Position of jack frames and axles Not allowed jacks from vertical 6. The greatest difference in the marks of the crossbars same type of jacking frames 7. “Taper” of sliding formwork by one 8. Reverse “taper” Not allowed 9. Distance between jacks, frames (beyond with the exception of places where the distance between the frames is free size) 10. Displacement of the jack axes from the axis of the const. 11. Displacement of the axes of the moved or re- the formwork being installed relative to the axes of the structure

Stripping of structures

2.28. When uncircling and dismantling structures supporting the formwork of vaults, arches, bunkers and other complex structures, as well as beam structures with a span of more than 8 m, the following requirements must be met:

the removal of supports should be preceded by untwisting of the structures (i.e., lowering of these supports);

unwinding should be carried out in several stages using means that ensure smooth lowering of the structures supporting the formwork;

the order of turning, the amount of lowering of supports supporting the formwork of structures, and other conditions of turning must correspond to those specified in the project;

before unwinding arches with strings, the strings must be tensioned;

The unraveling of dome coverings, as well as bunker funnels, should begin with the racks located in the center of the structure and should be carried out in concentric rows towards its perimeter.

2.29. Tear-off from concrete and detachment of internal formwork and outer contour panels in the absence of assembly scaffolds should be carried out after temporary fastening of the formwork to supporting structures or a lifting mechanism.

2.30. Severing from the concrete and lowering large-panel floor formwork (when dismantling in a block without a bulkhead) should be carried out with uniform, alternate operation of all support jacks

in order to eliminate the possibility of jamming and distortions.

2.31. Dismantling of sliding formwork should be carried out in large blocks in accordance with the work project.

2.32. The formwork and equipment must be disassembled in an order in which, after separating parts of the formwork and equipment, the stability and safety of the remaining elements is ensured.

2.33. Dismantling of thermoactive formwork should be carried out after disconnecting all panels from the electrical supply and removing the switching wiring from the working area.

3. REINFORCEMENT WORK General requirements

3.1. Reinforcement of reinforced concrete structures should be carried out with enlarged welded reinforcement frames and prefabricated meshes. Manufacturing of reinforcement directly on the construction site and reinforcement with piece rods is allowed for additional parts of reinforcement or for connection areas between meshes (frames).

3.2. Replacement of the reinforcing steel provided by the project by class, grade, range or replacement of the anchor design must be agreed upon with the design organization.

3.3. Upon acceptance, reinforcing steel, embedded parts and anchors supplied for construction must be subject to external inspection and measurements, as well as control tests in the following cases:

specified in the project or special instructions for the use of certain types of reinforcing steel;

doubts about the correctness of the characteristics of reinforcing steel, embedded parts and anchors, as well as the lack of necessary data in the certificates of manufacturers;

use of reinforcement as prestressed reinforcement.

Selection procedure, test methods and number of components*

UDC 693.54(083.75)

Chapter SNiP 111-15*76 “Concrete and reinforced concrete monolithic structures” was developed by the TsNIIOMTP Institute of the USSR State Construction Committee with the participation of NIIZHB, Donetsk Promstroyniproekt, Krasnoyarsk Industrial Construction Project of the USSR Gosstroy, Gorky Civil Engineering Institute named after. Chkalov Ministry of Higher Education of the RSFSR, VNIIG im. Vedeneev and Orgenergostroy of the USSR Ministry of Energy, Lenmorniiproekt of the USSR Ministry of Marine Fleet, TsNIIS of the USSR Ministry of Transport. With the entry into force of this chapter, Chapter SNiP III-B.1-70 “Concrete and reinforced concrete monolithic structures” becomes invalid. Rules for the production and acceptance of work" and "Instructions for the use of concrete with the addition of sulfite-yeast mash concentrates" (SN 406-70).

Editors - engineers L. Ya. Davydov,

© Stroyizdat, 1977

A. A. Lysogorsky (Gosstroy USSR), Ph.D. tech. Sciences B.I. Berezovsky, Doctor of Engineering. Sciences Ya. E. Nosenko, Ph.D. tech. Sciences V., D. Topchiy (TsNIIOMTP Gosstroy USSR), Doctor of Engineering. Sciences Ya. A. Krylov (NIIZhB Gosstroy USSR).

l 30213-511 „ .. . _

S O47(01)-7G Inst RU kt ’ n °R mat -1 11 ISS. - 1.11-77

role models are accepted according to the relevant GOSTs and technical specifications, as well as additional project instructions (if any).

If the data, accompanying documents and the results of the control tests do not comply with these project requirements, the batch of reinforcing steel is not allowed into production and can be used in agreement with the customer and the design organization for the appropriate purpose, taking into account its actual properties.

3.4. When accepting reinforcing steel, its compliance with the requirements of GOST or TU must be checked.

3.5. Corroded wire is not allowed for use. The wire is considered corroded if the corrosion products (plaque, rust) cannot be removed by wiping.

3.6. There should be no broken, crossed or broken wires in the reinforcing ropes; The wires should fit tightly to each other.

3.7. Reinforcing steel and fittings must be stored separately, in batches, and measures must be taken against its corrosion, contamination, and the safety of metal supplier tags and access to them must be ensured. Non-prestressing reinforcement should be stored under a shelter, and prestressing reinforcement and anchors should be stored in a closed, dry room. The rod reinforcement must be placed on racks; wire rod and wire reinforcement - in special compartments with metal fencing; ropes-on wooden flooring Anchors must be protected from corrosion, taking into account their design as well as storage conditions.

Preparation of non-prestressing reinforcement and its transportation

3.8. Preparation of reinforcing bars from steel bars should be carried out taking into account rational cutting. It is allowed to join rods by contact welding and friction welding, maintaining equal strength

State Committee of the Council of Ministers of the USSR for Construction Affairs (Gosstroy USSR)

1. GENERAL PROVISIONS

1.1. The rules of this chapter must be observed during the construction of monolithic concrete and reinforced concrete structures, monolithic parts and seams of prefabricated monolithic structures made of heavy, extra heavy, porous aggregates, heat-resistant, acid-resistant and alkali-resistant concrete, during shotcrete and underwater concreting work, as well as when production of prefabricated concrete and reinforced concrete structures in construction site conditions.

1.2. When constructing concrete and reinforced concrete structures, in addition to complying with the rules of this chapter, the requirements of the relevant state standards, chapters of SNiP must be met: on the organization of construction, safety precautions in construction and on the construction of special structures (bridges, airfields, hydraulic engineering, etc.), as well as rules fire safety during construction and installation work and instructions for the development of construction organization projects and work execution projects.

1.3. Materials used in the construction of concrete and reinforced concrete structures, their order

Approved by a resolution of the State Committee of the USSR Council of Ministers for Construction Affairs dated December 21, 1976.

tsniomtp

Gosstroy USSR

acceptance, testing, as well as their transportation and storage, must meet the requirements of relevant standards and technical specifications.

1.4. When developing technology for the construction of concrete and reinforced concrete structures, the following should be provided: comprehensive mechanization of production processes, the primary use of inventory reversible formwork, the use of enlarged volumetric and flat reinforcement products, the use of ready-mixed concrete mixtures prepared in automated concrete mixing plants, and also take into account the properties of concrete in terms of strength and density , frost resistance, uniformity and its structure and other requirements provided for by the project.

2. FORMWORK

General requirements

2.1. When constructing formwork, the following requirements must be observed:

the formwork must have the necessary strength, rigidity and immutability under the influence of technological loads (loads and data for formwork calculations are given in Appendix 1) and low adhesion to concrete;

must ensure the specified accuracy of the dimensions of structures, as well as the correct position of the structure in space. The design of the formwork must allow it to be quickly installed and dismantled without damaging the concrete;

do not interfere with the convenience of installing reinforcement, laying and compacting the concrete mixture. When assembling formworks, the required density in the connections of individual elements must be ensured;

compensators will be provided to reduce temperature stresses when the concrete is heated. The formwork design must allow reassembly during the construction process.

As a rule, unified standard formwork systems with modular changes in size should be used. To assemble formwork forms of non-standard structures and structures (including those with curved surfaces of the second and third order of curvature, with a complex configuration in plan, etc.), it is allowed to use stationary (non-reversible) formwork from various materials, manufactured and installed on site.

2.2. The installation of formwork must be carried out according to the work plan.

2.3. Tie bolts and tie rods, as well as fastening elements, must be in stock and can be quickly installed and removed. Non-inventory ties and twists can be used when constructing formwork for individual small-volume structures.

2.4. The use of suspended formwork attached to rigid reinforcement or to reinforcement cages, which absorb the pressure of the mass of the concrete mixture and production loads, is allowed only in cases where such formwork is provided for by the construction design.

2.5. Dimensions of formwork and stops at. in the manufacture of pre-stressed reinforced concrete structures should be assigned taking into account deformations due to compression forces.

2.6. When using formwork in winter conditions, it must be possible to insulate it or install heating elements in it.

2.7. The choice of formwork is determined by the type and size of the structures being concreted and the method of producing reinforcement and concrete work. The characteristics of the main types of formwork and their scope of application are given in table. 1.

Table ]

Formwork Characteristics of formwork Application area 1. Collapsible and adjustable small panel: a) inventory unified It consists of a set of small-sized elements weighing no more than 50 kg and panels with an area of ​​​​about 1 m 2, load-bearing elements (screws, stiffening elements), supporting formwork elements of horizontal and inclined surfaces, fastening and connecting elements, allows for tiered rearrangement with a minimum number of additional elements^ as well as the assembly of enlarged elements, assembly of enlarged panels and spatial blocks For concreting various types of monolithic structures, including curved ones b) non-unified For concreting small-volume structures with repeated formwork turnover until worn out c) non-inventory For single atypical structures that do not have repeating elements 2. Collapsible large panel Consists of large-sized panels, connection and fastening elements. Formwork panels absorb all technological loads without installing additional load-bearing or supporting elements and include a deck, stiffeners and load-bearing elements. It is equipped with scaffolding, struts, adjusting 4 and installation jacks, allows the installation of tiers of the next highest height after dismantling the lower ones For large-sized massive structures, walls (including curved ones)

SNiP 111-15-76

3. Lifting and adjustable Consists of panels, fastenings, lifting devices, a system for controlling the movement of formwork and monitoring the accuracy of movement and horizontal floor level, allows for changes in the transverse concreted structure when moving the formwork in height For structures and structures of variable cross-section (chimneys, cooling towers, etc.) 4. Horizontal sliding (rolling) It consists of a frame and formwork panels attached to it (movably or stationarily), a mechanism for moving horizontally and vertically, a control system and monitoring the accuracy of movement during the concreting process, allows changes in the cross-section of the structure and the radius of its curvature, has a taper within Viooo Length formwork panels For long-distance structures, including curved ones (retaining walls, tunnels, sewers, water conduits and other open-pit structures) 5. Tunnel Consists of forming and supporting sections and moves using special mechanisms with mechanical, hydraulic and other drives For concreting monolithic lining of tunnels constructed using closed methods 6. Block form For free-standing closed-loop structures or parts thereof with a volume of up to 25-30 m3 (columns, grillages, stepped foundations, etc.)

SNiP Sh-15-76

Continuation of the table. 1

Formwork Characteristics of formwork Application area 7. Custom block forms: a) one-piece b) detachable They are a spatial frame structure consisting of 4 or 8 sashes with a taper VlO HEIGHT of the sashes. Total surface area 6-10 m3 They are a spatial frame structure consisting of 4-12 sashes. The doors are united by a frame on each side and have connecting devices in the corners. Before dismantling, the sashes are separated from the concrete using pressing devices. Total surface area 8-10 m3 For concreting similar structures of small volume up to 5 m 3 with stripping at an early age (no later than 24 hours) For concreting similar structures with a volume of up to 15 m 3 8. Reconfigurable block forms They allow changes in the dimensions in plan and height of both individual sashes and the entire block form due to inventory inserts of frame elements and sashes. They have squeezing devices for preliminary separation of the sashes from the concrete during dismantling. Surface area 8-40 m2 For concreting structures that differ in both linear dimensions and configuration 9. Volume-adjustable Consists of vertical and horizontal sashes, hinged For the construction of residential and civil buildings with transverse load-bearing

SNiP II1-15-76

on a U-shaped frame, which when connected along the length form tunnels. A system of tunnels installed parallel and perpendicular to each other forms a form for concreting walls and ceilings. When stripping the formwork, the sashes are separated from the concrete walls and monolithic coverings 10. Sliding It consists of panels mounted on jacking frames, a working floor, jacks, pumping stations and other elements. The entire system is periodically lifted with jacks as concreting proceeds, allowing taper within V550 of the height of the panels For the construction of vertical buildings and structures more than 15 m high 11. Pneumatic It consists of a flexible airtight shell, cut in accordance with the outline of the structure. Installation into the working position is carried out by creating excess air pressure inside the shell. Pneumatic cylinders can be used as supporting and load-bearing elements For structures with a curved outline 12. Fixed Remaining in the structure after concreting, as well as blocks and shells that are firmly connected to the main structure during concreting For the manufacture of structures without stripping, for cladding, waterproofing or thermal insulation of structures^ also in other cases with an appropriate feasibility study

SNiP IIM5-76

SNiP III-15-76. Building regulations. Part III. Rules for production and acceptance of work. Chapter 15. Monolithic concrete and reinforced concrete structures.

The document has become invalid.

(text of the document with changes and additions as of November 2014.

Instead of chapter SNiP III-B.1-70 and SN 406-70.

Introduced by TsNIIOMTP of the USSR State Construction Committee.

Approved by Resolution of the State Committee of the USSR Council of Ministers for Construction Affairs dated December 21, 1976 N 217.

Chapter SNiP III-15-76 “Concrete and reinforced concrete monolithic structures” was developed by the TsNIIOMTP Institute of the USSR Gosstroy with the participation of NIIZHB, Donetsk Promstroyniproekt, Krasnoyarsk Promstroyniyproekt of the USSR Gosstroy, Gorky Civil Engineering Institute named after. Chkalov Ministry of Higher Education of the RSFSR, VNIIG im. Vedeneev and Orgenergostroy of the USSR Ministry of Energy, Lenmorniiproekt of the USSR Ministry of Marine Fleet, TsNIIS of the USSR Ministry of Transport. With the entry into force of this chapter, Chapter SNiP III-B.1-70 “Concrete and reinforced concrete monolithic structures” becomes invalid. Rules for the production and acceptance of work" and "Instructions for the use of concrete with the addition of sulfite-yeast mash concentrates" (SN 406-70.

Editors: engineers A.I. Davydov, A.A. Lysogorsky (Gosstroy USSR), Ph.D. tech. Sciences B.I. Berezovsky, Doctor of Engineering. Sciences N.E. Nosenko, Ph.D. tech. Sciences V.D. Topchiy (TsNIIOMTP Gosstroy USSR), Doctor of Engineering. Sciences B.A. Krylov (NIIZhB Gosstroy USSR.

1. GENERAL PROVISIONS.

1.1. The rules of this chapter must be observed during the construction of monolithic concrete and reinforced concrete structures, monolithic parts and seams of prefabricated monolithic structures made of heavy, extra heavy, porous aggregates, heat-resistant, acid-resistant and alkali-resistant concrete, during shotcrete and underwater concreting work, as well as when production of prefabricated concrete and reinforced concrete structures in construction site conditions.

1.2. When constructing concrete and reinforced concrete structures, in addition to complying with the rules of this chapter, the requirements of the relevant state standards, chapters of SNiP must be met: on the organization of construction, safety precautions in construction and on the construction of special structures (bridges, airfields, hydraulic engineering, etc.), as well as rules fire safety during construction and installation work and instructions for the development of construction organization projects and work execution projects.

1.3. The materials used in the construction of concrete and reinforced concrete structures, the procedure for their acceptance, testing, as well as their transportation and storage must meet the requirements of the relevant standards and technical specifications.

1.4. When developing technology for the construction of concrete and reinforced concrete structures, the following should be provided: comprehensive mechanization of production processes, the primary use of inventory reversible formwork, the use of enlarged volumetric and flat reinforcement products, the use of ready-mixed concrete mixtures prepared in automated concrete mixing plants, and also take into account the properties of concrete in terms of strength and density , frost resistance, uniformity and its structure and other requirements provided for by the project.

2. FORMWORK.

General requirements.

2.1. When constructing formwork, the following requirements must be observed.

the formwork must have the necessary strength, rigidity and immutability under the influence of technological loads (loads and data for calculating formwork are given in Appendix 1) and low adhesion to concrete.

must ensure the specified accuracy of the dimensions of structures, as well as the correct position of the structure in space. The design of the formwork must allow it to be quickly installed and dismantled without damaging the concrete.

do not interfere with the convenience of installing reinforcement, laying and compacting the concrete mixture. When assembling the formwork, the required density in the connections of individual elements must be ensured.

compensators will be provided to reduce temperature stresses when the concrete is heated. The formwork design must allow reassembly during the construction process.

As a rule, unified standard formwork systems with modular changes in size should be used. To assemble formwork forms of non-standard structures and structures (including those with curved surfaces of the second and third order of curvature, with a complex configuration in plan, etc.), it is allowed to use stationary (non-reversible) formwork from various materials, manufactured and installed on site.

2.2. The installation of formwork must be carried out according to the work plan.

2.3. Tie bolts and tie rods, as well as fastening elements, must be in stock and can be quickly installed and removed. Non-inventory ties and twists can be used when constructing formwork for individual small-volume structures.

2.4. The use of suspended formwork attached to rigid reinforcement or to reinforcement cages, which absorb the pressure of the mass of the concrete mixture and production loads, is allowed only in cases where such formwork is provided for by the construction design.

2.5. The dimensions of formwork and stops in the manufacture of prestressed reinforced concrete structures should be determined taking into account deformations due to compression forces.

2.6. When using formwork in winter conditions, it must be possible to insulate it or install heating elements in it.

2.7. The choice of formwork is determined by the type and size of the structures being concreted and the method of producing reinforcement and concrete work. The characteristics of the main types of formwork and their scope of application are given in table. 1.

Formwork materials.

2.8. The load-bearing elements of the inventory formwork, its fastening parts and the structures supporting the formwork should be made from materials specified in the project, observing the requirements of technical rules for the economical use of basic building materials.

2.9. Formwork elements (panels) in contact with concrete should be made primarily of waterproof plywood. The use of lumber is allowed for the manufacture of additional elements and inventory panels with a turnover of no more than 10 times.

2.10. The following requirements apply to timber and materials made from wood and used for formwork and its supporting structures.

posts with a height of more than 3 m, purlins supporting the formwork and deck elements in contact with concrete must be made only from coniferous wood of at least grade III. For bending elements, lumber of at least grade II must be used. For other elements of formwork and fastenings, hardwood (aspen, alder) can be used. Birch should not be used for decks.

inventory elements of formwork and scaffolding (column clamps, inventory racks, etc.) must be made from grade II lumber.

For the manufacture of load-bearing frames, coniferous wood with a moisture content of no more than 15% should be used, for other elements - with a moisture content of no more than 25.

formwork boards directly adjacent to the concrete must be planed and have a width of no more than 150 mm. Boards used in sliding formwork for cladding should be no wider than 120 mm.

plywood used to make formwork must be waterproof. The working and end surfaces of the plywood board must be protected with a waterproof coating made of polymer materials, laminated paper, and fiberglass.

Particle boards and fibreboards used for the manufacture of inventory formwork must be hydrophobic or have a protective coating made of synthetic materials.

2.11. The metal mesh used for permanent formwork must have cells measuring no more than 5 x 5 mm. Before installation and concreting, the mesh must be degreased.

2.12. Concrete and reinforced concrete formwork, as well as other materials included in the erected structure for formwork elements (ceramics, glass, asbestos cement, etc.) must meet the requirements for the structures being erected.

Materials for glass-cement shell slabs, which act as formwork for monolithic structures and operate in aggressive environments, must meet the requirements for waterproofing and chemically resistant coatings.

2.13. Electric heaters for thermoactive formwork must be standard, mass-produced, closed type. For one or two-time use, it is allowed to use non-standard heaters, which must meet the requirements of vibration resistance, electrical strength and fire safety.

2.14. The insulation of thermoactive formwork must be fireproof, have a low volumetric mass, as well as sufficient mechanical stability and a low thermal conductivity coefficient that does not change during the period of use in the formwork.

Acceptance of formwork elements.

2.15. All elements of inventory formwork must arrive marked from manufacturers. Visual control of the quality of formwork at the construction site should be carried out before assembly. Periodic instrumental inspection should be carried out: steel elements - at least every 20 revolutions; elements made of wood after 5 turns. Deviations from the design dimensions of the formwork should not exceed the values ​​​​given in table. 2.

2.16. Before assembling thermoactive formwork, the condition of the insulation, the outer protective cover, the fastening of electrical connectors, and the presence on the insulation cover of the designation of the formwork characteristics: design heat transfer coefficient, specific power of heaters and operating voltage must be checked. During operation, electrical characteristics, including electrical insulation resistance, must be monitored at least once after 5 rotations of the formwork.

2.17. The arrangement of electric heaters and insulation in thermoactive formwork panels should ensure a uniform temperature field on the plane with a temperature difference at its individual points of no more than 5 °C.

The design of the formwork insulation must ensure thermal insulation of the intermediate stiffening ribs of the formwork panels and eliminate heat loss.

2.18. Steel surfaces of formwork elements and supporting structures that are not in contact with concrete must be painted with weather-resistant paints.

Transportation and storage of formwork.

2.19. Transportation of inventory formwork elements must be carried out according to the project. In the absence of special requirements for transportation, the conditions set out in table must be observed. 3.

2.20. All elements of inventory formwork must be stored in a position corresponding to transport, sorted by brand and standard size. Hinge joints and threaded elements must be coated with anti-corrosion lubricants.

Thermoactive shields should be stored under canopies or shelters made of moisture-proof materials on areas that prevent them from getting wet.

2.21. Woven metal mesh and fabric materials pneumatic formwork should be stored under canopies in rolls under conditions that prevent cracks and other damage from occurring on the fabric.

2.22. Volume-adjustable, rolling and tunnel formwork can be stored in working position. Horizontal working planes must be coated with anti-corrosion lubricants and moisture-proof materials (polyethylene films, roofing felt, etc.

Installation and acceptance of formwork.

2.23. The assembly of formwork forms from elements of inventory formwork, as well as the installation of volumetric-adjustable, sliding, tunnel and rolling formwork into the working position must be carried out in accordance with the technological rules for their assembly.

The forming surfaces of the formwork must be lubricated with anti-adhesive grease.

2.24. When installing structures supporting formwork, the following requirements must be met.

the racks must be installed on foundations that have a supporting area sufficient to protect the concreted structure from unacceptable subsidence.

ties, screeds and other fastening elements should not interfere with concreting.

fastening of ties and braces to previously concreted structures should be carried out taking into account the strength of the concrete at the moment the loads from these fastenings are transferred to it.

the base for the formwork must be leveled before installation.

2.25. The formwork and surrounds of reinforced concrete arches and vaults, as well as the formwork of reinforced concrete beams with a span of more than 4 m, must be installed with a construction lift.

The outline of the construction rise circles and the formwork of arches and vaults must be installed in accordance with the project. The amount of construction lift must be at least 5 mm per 1 m span of arches and vaults, and for beam structures - at least 3 mm per 1 m span.

2.26. Upon acceptance of the installed formwork, its supporting structures and fastenings are subject to inspection.

load-bearing foundations supporting the formwork of the structure and the formwork itself.

the rigidity and immutability of the entire system as a whole and the correct installation of structures supporting the formwork.

correct installation of formwork, plugs and embedded parts.

the density of the formwork panels and the joints connecting the formwork elements to each other and to the previously laid concrete.

formwork surfaces and their position relative to the design axes of structures to be concreted.

2.27. Permissible deviations of the positions and dimensions of the installed formwork and supporting scaffolding from the design should not exceed those indicated in the table. 4.

The formwork assembled and prepared for concreting, as well as equipment for lifting it, must be accepted according to the act.

The condition of the installed formwork, scaffolding and fastenings must be continuously monitored during the concreting process. Checking the correct position of the axes of volumetrically adjustable and horizontally moving (rolling) formworks should be carried out after each rearrangement. If deformation or displacement of individual elements of the formwork, scaffolding and fastenings is detected, measures must be taken immediately to eliminate the deformations and, if necessary, concreting work in this area must be temporarily stopped.

Stripping of structures.

2.28. When uncircling and dismantling structures supporting the formwork of vaults, arches, bunkers and other complex structures, as well as beam structures with a span of more than 8 m, the following requirements must be met.

Removal of supports must be preceded by untwisting of structures (i.e. lowering of these supports.

unwinding should be carried out in several stages using means that ensure a smooth lowering of the structures supporting the formwork.

the order of untwirling, the amount of lowering of supports supporting the formwork of structures, and other conditions of untwirling must correspond to those specified in the project.

Before untwisting arches with strings, tensioning of the strings must be done.

The unraveling of dome coverings, as well as bunker funnels, should begin with the racks located in the center of the structure and should be carried out in concentric rows towards its perimeter.

2.29. Tear-off from concrete and detachment of internal formwork and outer contour panels in the absence of assembly scaffolds should be carried out after temporary fastening of the formwork to supporting structures or a lifting mechanism.

2.30. The separation from the concrete and lowering of large-panel floor formwork (when dismantling in a block without a bulkhead) should be carried out with uniform, alternate operation of all support jacks in order to eliminate the possibility of jamming and distortions.

2.31. Dismantling of sliding formwork should be carried out in large blocks in accordance with the work project.

2.32. The formwork and equipment must be disassembled in an order in which, after separating parts of the formwork and equipment, the stability and safety of the remaining elements is ensured.

2.33. Dismantling of thermoactive formwork should be carried out after disconnecting all panels from the electrical supply and removing the switching wiring from the working area.

3. REINFORCING WORK.

General requirements.

3.1. Reinforcement of reinforced concrete structures should be carried out with enlarged welded reinforcement frames and prefabricated meshes. The manufacture of reinforcement directly on the construction site and reinforcement with piece rods are allowed for additional parts of the reinforcement or for connection sections between meshes (frames.

3.2. Replacement of the reinforcing steel provided by the project by class, grade, range or replacement of the anchor design must be agreed upon with the design organization.

3.3. Upon acceptance, reinforcing steel, embedded parts and anchors arriving for construction must be subject to external inspection and measurements, as well as control tests in cases.

specified in the project or special instructions for the use of certain types of reinforcing steel.

doubts about the correctness of the characteristics of reinforcing steel, embedded parts and anchors, as well as the lack of necessary data in the certificates of manufacturers.

use of reinforcement as prestressed reinforcement.

The selection procedure, testing methods and the number of control samples are adopted in accordance with the relevant GOSTs and technical conditions, as well as additional project instructions (if any.

If the data in the accompanying documents and the results of the control tests do not comply with these project requirements, the batch of reinforcing steel is not allowed into production and can be used in agreement with the customer and the design organization for the appropriate purpose, taking into account its actual properties.

3.4. When accepting reinforcing steel, its compliance with the requirements of GOST or TU must be checked.

3.5. Corroded wire is not allowed for use. The wire is considered corroded if the corrosion products (plaque, rust) cannot be removed by wiping.

3.6. There should be no broken, crossed or broken wires in the reinforcing ropes; The wires should fit tightly to each other.

3.7. Reinforcing steel and fittings must be stored separately, in batches, and measures must be taken against its corrosion, contamination, and the safety of metal supplier tags and access to them must be ensured. Non-prestressing reinforcement should be stored under a shelter, and prestressing reinforcement and anchors should be stored in a closed, dry room. Rod reinforcement must be placed on racks; wire rod and wire reinforcement - in special compartments with metal fencing; ropes - on wooden floorings. Anchors must be protected from corrosion, taking into account their design as well as storage conditions.

Preparation of non-prestressed reinforcement and its transportation.

3.8. Preparation of reinforcing bars from steel bars should be carried out taking into account rational cutting. It is allowed to join the rods by contact welding and friction welding, observing the equal strength of the butt joint and deburring. The preparation of bars of measured length from steel supplied in coils must be carried out on machines.

Metal waste during cutting should not exceed 1% of the mass of processed steel.

3.9. The production of reinforcement frames and meshes must be carried out in jigs that ensure the precise location of the elements to be welded.

3.10. Load-bearing reinforcement frames using rods with a diameter of more than 32 mm must be manufactured taking into account the requirements for the manufacture, installation and acceptance of metal structures.

3.11. When transporting reinforcement products, measures should be taken to protect them from corrosion, contamination and mechanical damage.

3.12. It is allowed, in agreement with the design organization, to cut large-sized welded reinforcement products into parts whose dimensions correspond to the dimensions of the vehicles used and the load-carrying capacity of the equipment. Compound individual parts of the cut product must be carried out according to the specific instructions of the project.

3.13. Places for gripping large-sized reinforcement products during lifting and installation, their support during transportation and storage must be marked in accordance with the working drawings of the products. Slinging of reinforcing products is carried out in such a way as to ensure their integrity, specified mutual arrangement reinforcement bars in products and the absence of residual deformations in the bars.

Installation of fittings.

3.14. Installation of fittings should be carried out in large blocks, fulfilling the following requirements.

Before installing the reinforcement, the formwork must be checked. Identified defects must be eliminated.

The fittings must be installed in a sequence that ensures their correct position and fastening. Before installing the fittings, pads (crackers made from cement mortar), providing the gap between the reinforcement and the formwork necessary for the formation of a protective layer.

the mounted reinforcement must be secured against displacement and protected from damage that may occur during the concreting of the structure.

Attaching pedestrian, transport and other production or installation devices to the fittings should be carried out only in places established by the work plan.

3.15. Butt connections of reinforcement should be made using resistance butt and spot welding, semi-automatic submerged arc welding and flux-cored wire in inventory forms; single-electrode or multi-electrode arc welding pool in inventory forms.

3.16. It is allowed to weld butt joints using a single-electrode arc bath and bath-seam welding with remaining steel linings or overlays; arc semi-automatic and single-electrode welding with multilayer seams; arc welding long seams with paired overlays or overlaps.

3.17. Cross intersections of reinforcement bars mounted individually, in the places of their intersection established in the project, should be fastened with tying wire or using special wire connecting elements (clips). When the diameter of the rods is over 25 mm, their fastening should be performed by arc welding.

3.18. The displacement of reinforcing bars when installing them in formwork, as well as during the manufacture of reinforcing cages and meshes should not exceed 1/5 largest diameter rod and 1/4 of the diameter of the rod being installed.

3.19. Acceptance of mounted reinforcement, as well as welded butt joints, must be carried out before laying concrete and documented in an inspection report for hidden work. In case of rejection of welded joints made during installation of reinforcement by bath welding, based on the results of selective inspection in accordance with current standards, it is allowed to check the quality of these joints piece by piece by ultrasonic flaw detection and correct only those joints that will be rejected during ultrasonic testing.

3.20. The design location of reinforcing bars and mesh must be ensured by the correct installation of supporting devices, templates, clamps, stands, spacers and pads. The use of pads made from scraps of reinforcement, wooden blocks and crushed stone is prohibited.

3.21. Deviations from the design thickness of the concrete protective layer should not exceed.

3 mm - with a protective layer thickness of 15 mm or less.

5 mm - with a protective layer thickness of more than 15 mm.

Preparation, installation and tension of prestressing reinforcement.

3.22. High-tensile wire and reinforcement ropes must be cut using mechanical shears or friction circular saws. cutting them electric arc not allowed.

3.23. Before installing them on reinforcement bundles made of high-strength wire or reinforcing ropes, anchors must be cleaned of preservative lubricant. Anchor heads on reinforcing wires must be cold formed and have correct form. Bevels, curvatures and deviations in their dimensions by more than 0.4 mm are not allowed on the anchor heads. The tear strength of anchor heads must be at least 0.97 of the standard wire strength. Before starting work, as well as after planting every ten thousand heads and in cases of replacement or repair of planting equipment, at least 6 pieces must be tested. control samples of heads.

3.24. Anchors and grips are accepted according to passports, which must indicate: data on the project for which they are manufactured, the main dimensions of these anchors and grips, steel grade, heat treatment of parts, test results of samples selected from a batch manufactured using the same technology from some materials. The batch size of anchors and grips should not exceed 100 sets.

3.25. The quality of anchors and grips used to secure prestressed reinforcement should be checked based on the results of control tests of samples consisting of a section of prestressed reinforcement with anchors or grips attached to its ends.

Two control samples from each batch of anchors or grips should be tested for tensile strength. The batch is considered suitable if both control samples withstood a force of at least 0.9 of the standard resistance of the original reinforcing steel.

Otherwise, four more control samples from the lot must be tested. The results of these tests are final.

3.26. During the installation of prestressed reinforcement, it is not allowed to weld (tackle) distribution reinforcement, clamps and embedded parts to it, as well as to hang formwork, equipment, etc.

Installation of reinforcement tensioned on concrete should be carried out immediately before tensioning in order to eliminate the possibility of corrosion. When pulling reinforcement through channels, precautions should be taken to prevent damage.

3.27. The project for carrying out work on tensioning prestressing reinforcement must be indicated.

forces controlled at the end of tensioning of reinforcement.

losses of reinforcement prestress taken into account when determining the force controlled at the end of tensioning of the reinforcement.

other requirements that must be met when compressing the block with prestressing reinforcement.

3.28. When tensioning reinforcement on concrete structures, the following requirements must be met.

the strength of the concrete structure and joints must be no lower than that established by the design for this stage, which must be confirmed by the results of testing control samples; Before tensioning begins, it is necessary to check the compliance of the actual dimensions of the structure with the design ones and make sure that there are no sinkholes or other defects that weaken the concrete of the structure.

the crimped structure must be supported in the places specified in the design, and the support units must be free to move.

in places where anchors and jacks are installed, the concrete (metal) surface must be flat and perpendicular to the direction of the reinforcement; When installed, anchors and jacks must be centered along the axis of the reinforcement and maintain this position during the tension period.

tensioned reinforcement must be injected, concreted or coated with anti-corrosion compounds provided for by the project, within a time frame that prevents its corrosion.

3.29. When tensioning reinforcement on stops, the following requirements must be observed.

pre-select the slack of all curved reinforcement and straight reinforcement for a length exceeding 18 m; when simultaneously tensioning a group of bundles or ropes, tighten them with a force equal to 0.2 of the force controlled during tension, and secure them in the tightened position.

monitor the condition and location of the reinforcement in the structure, as well as holding devices - in places of inflection; in the case of tensioning polygonal reinforcement, install guy wires so that the design position of the reinforcement after tension is ensured.

install jacks with group tensioning of reinforcement symmetrically relative to the resultant pre-tensioning force with an accuracy of 10 mm.

provide compensation for tension losses arising due to deformation of the spacer structure, as well as due to the temperature difference between the reinforcement at the end of its tension and the concrete during its hardening.

electric heating of the rod reinforcement should be carried out outside the place of its fastening to a temperature not exceeding the values ​​​​established by the project.

3.30. The transfer of the tensile force of the reinforcement from the stops to the concrete of the structure can be carried out once the latter reaches a strength not lower than that specified in the design for the compression stage, which must be confirmed by testing control concrete samples. In this case, the following requirements must be met.

The structure must be stripped and inspected before crimping. If defects are discovered that reduce the strength of the structure, these defects must be eliminated with the consent of the design organization.

the structure must be supported in the places provided for by the design, have freedom of movement and not be subjected to loads not provided for by the design.

compression of structures must be carried out smoothly, the order and sequence of releasing individual beams must correspond to those established in the work project.

Before cutting the reinforcement with an autogen, it must be heated to a red glow in a section at least 20 cm long from the end of the structure to the stop.

(approved by resolution of the USSR State Construction Committee dated December 4, 1987 N 280) (as amended on May 22, 2003) Replaces SNiP III-15-76; CH 383-67; SNiP III-16-80; SN 420-71; SNiP III-18-75; SNiP III-17-78; SNiP III-19-76; CH 393-78

Document text

Construction norms and rules SNiP 3.03.01-87
"Load-bearing and enclosing structures"
(approved by Decree of the USSR State Construction Committee dated December 4, 1987 N 280)
(as amended May 22, 2003)

Instead of SNiP III-15-76; CH 383-67; SNiP III-16-80; SN 420-71;

SNiP III-18-75; SNiP III-17-78; SNiP III-19-76; CH 393-78

installation works of building structures

anti-corrosion protection of welded joints

embedding installation joints and assemblies

execution installation connections bolted with

controlled tension

curing concrete during winter concreting

monolithic structures

diamond tools for processing concrete and

monolithic concrete and reinforced concrete structures

reservoir (water tower tank)

solutions and their compositions

additives in solutions, conditions for their use and expected

mortar strength

Concrete mixtures

2.3. Dosing of concrete mixture components should be done by weight. It is allowed to dose additives introduced into the concrete mixture in the form of aqueous solutions by volume of water. The ratio of components is determined for each batch of cement and aggregates when preparing concrete of the required strength and mobility. The dosage of components should be adjusted during the preparation of the concrete mixture, taking into account data from monitoring indicators of cement properties, humidity, granulometry of aggregates and strength control.

2.4. The order of loading components and the duration of mixing the concrete mixture must be established for specific materials and conditions of the concrete mixing equipment used by assessing the mobility, uniformity and strength of concrete in a specific batch. When introducing pieces of fibrous materials (fibers), it is necessary to provide a method for their introduction so that they do not form lumps and inhomogeneities.

When preparing a concrete mixture using separate technology, the following procedure must be observed:

water, part of the sand, finely ground mineral filler (if used) and cement are dosed into a running 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.

2.5. Transportation and supply of concrete mixtures should be carried out using specialized means that ensure the preservation of the specified properties of the concrete mixture. It is prohibited to add water at the site of laying the concrete mixture to increase its mobility.

2.6. The composition of the concrete mixture, preparation, acceptance rules, control methods and transportation must comply with GOST 7473-85.

Instead of GOST 7473-85, by resolution of the Ministry of Construction of Russia dated June 26, 1995, GOST 7473-94 was put into effect

2.7. Requirements for the composition, preparation and transportation of concrete mixtures are given in Table 1.

Table 1

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