Bearing and enclosing structures snip 3 03 01 87. Bearing and enclosing structures. documents on quality control of welded joints

This set of rules was developed in order to improve the quality of construction and installation works, the durability and reliability of buildings and structures, as well as the level of safety of people at the construction site, the safety of material assets in accordance with N 384-FZ of December 30, 2009 "Technical Regulations on safety of buildings and structures", increasing the level of harmonization of regulatory requirements with European and international regulatory documents; application of uniform methods for determining operational characteristics and evaluation methods.

3.5 Data on the production of construction and installation works should be entered daily in the work logs for the installation of building structures (), welding (), anti-corrosion protection of welded joints (), monolithic field joints and assemblies (), performing field connections on bolts with controlled tension ( ), a journal of concrete works (), and also fix their position on the geodetic executive schemes during the installation of structures. The quality of construction and installation works must be ensured by the current control of the technological processes of preparatory and main works, as well as during the acceptance of works. According to the results of the current control of technological processes, certificates of examination of hidden works are drawn up.

3.6 Structures, products and materials used in the construction of concrete, reinforced concrete, steel, wood and stone structures must meet the requirements of the relevant standards, codes of practice and working drawings.

3.7 Transportation and temporary storage of structures (products) in the installation area should be carried out in accordance with the requirements of state standards for these structures (products), and for non-standardized structures (products), the following requirements must be observed:

Structures should, as a rule, be in a position corresponding to the design (beams, trusses, slabs, wall panels, etc.), and if this condition cannot be met, in a position convenient for transportation and transfer to installation (columns, flights of stairs etc.) provided that their strength is ensured;

Structures should be based on inventory linings and gaskets of rectangular section, located in the places indicated in the project; the thickness of the gaskets must be at least 30 mm and at least 20 mm higher than the height of the sling loops and other protruding parts of the structures; for multi-tiered loading and storage of the same type of structures, linings and gaskets should be located on the same vertical along the line of lifting devices (loops, holes) or in other places indicated in the working drawings;

(approved by Decree of the USSR Gosstroy of December 4, 1987 N 280) (as amended on May 22, 2003) Instead of SNiP III-15-76; CH 383-67; SNiP III-16-80; CH 420-71; SNiP III-18-75; SNiP III-17-78; SNiP III-19-76; CH 393-78

Document text

Building codes and rules SNiP 3.03.01-87
"Bearing and enclosing structures"
(approved by the Decree of the Gosstroy of the USSR of December 4, 1987 N 280)
(as amended May 22, 2003)

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

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

works on the installation of building structures

corrosion protection of welded joints

monolithic mounting joints and nodes

making mounting connections on bolts with

controlled tension

curing of concrete during winter concreting

monolithic structures

diamond tools for concrete processing and

monolithic concrete and reinforced concrete structures

tank (water tower tank)

solutions and their compositions

additives in solutions, the conditions for their use and the expected

mortar strength

Concrete mixtures

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

2.4. The order of loading the components, the duration of mixing the concrete mixture should be established for specific materials and conditions of the concrete mixing equipment used by evaluating the mobility, uniformity and strength of concrete in a particular batch. When introducing segments of fibrous materials (fibers), such a method of their introduction should be provided so that they do not form lumps and inhomogeneities.

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

water, part of the sand, finely ground mineral filler (if used) and cement are dosed into a working high-speed mixer, where everything is mixed;

the resulting mixture is fed into a concrete mixer, pre-loaded with the rest of the aggregates and water, and once again everything is mixed.

2.5. Transportation and supply of concrete mixtures should be carried out by specialized means that ensure the preservation of the specified properties of the concrete mixture. It is forbidden to add water at the place 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 a decree 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 mixes are given in Table 1.

Table 1

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SNiP 3.03.01-87

BUILDING REGULATIONS

CARRYING AND Fencing

DESIGNS

Introduction date 1988-07-01

DEVELOPED BY TsNIIOMTP Gosstroy of the USSR (Doctor of Technical Sciences V.D.Topchiy; Candidates of Technical Sciences Sh.L.Machabeli, R.A.Kagramanov, B.V.Zhadanovsky, Yu.B.Chirkov, V.V.Shishkin , N.I.Evdokimov, V.P.Kolodiy, L.N.Karnaukhova, I.I.Sharov, Doctor of Technical Sciences K.I.Bashlay, A.G.Prozorovsky); NIIZhB Gosstroy of the USSR (Doctor of Technical Sciences B.A. Krylov; Candidates of Technical Sciences O.S. Ivanova, E.N. Malinsky, R.K. Zhitkevich, B.P. Goryachev, A.V. Lagoida, N.K.Rozental, N.F.Shesterkina, A.M.Friedman, Doctor of Technical Sciences V.V.Zhukov); VNIPIPromstalkonstruktsiya Minmontazhspetsstroy of the USSR (B.Ya. Moyzhes, B.B. Rubanovich), TsNIISK im. Kucherenko of the Gosstroy of the USSR (Doctor of Technical Sciences L.M. Kovalchuk; Candidates of Technical Sciences V.A. Kameiko, I.P. Preobrazhenskaya; L.M. Lomova); Central Research Institute of Projectstalconstruction of the State Construction Committee of the USSR (B.N. Malinin; Candidate of Technical Sciences V.G. Kravchenko); VNIIMontazhspetsstroy of the USSR Minmontazhspetsstroy (G.A. Ritchik); TsNIIEP housing of the State Committee for Architecture (S.B. Vilensky) with the participation of Donetsk Promstroyniiproekt, Krasnoyarsk Promstroyniiproekt of Gosstroy of the USSR; Gorky Engineering and Construction Institute. Chkalov of the USSR State Committee for Public Education; VNIIG them. Vedeneev and Orgenergostroy of the Ministry of Energy of the USSR; TsNIIS of the Ministry of Transport of the USSR; Aeroproject Institute of the USSR Ministry of Civil Aviation; NIIMosstroy of the Moscow City Executive Committee.

INTRODUCED by TsNIIOMTP Gosstroy of the USSR.

PREPARED FOR APPROVAL by the Department of Standardization and Technical Standards in Construction of the USSR State Construction Committee (A. I. Golyshev, V. V. Bakonin, D. I. Prokofiev).

APPROVED by the Decree of the State Construction Committee of the USSR of December 4, 1987 No. 280

With the entry into force of SNiP 3.03.01-87 "Bearing and enclosing structures" lose their force:

chapter SNiP III-15-76 "Monolithic concrete and reinforced concrete structures";

SN 383-67 "Guidelines for the production and acceptance of work during the construction of reinforced concrete tanks for oil and oil products";

chapter SNiP III-16-80 "Concrete and reinforced concrete prefabricated structures";

SN 420-71 "Guidelines for sealing joints during installation of building structures";

chapter on the installation of structures";

clause 11 of the Amendments and Additions to Chapter SNiP III-18-75 "Metal Structures", approved by the Decree of the USSR Gosstroy of April 19, 1978 No. 60;

head of SNiP III-17-78 | Stone structures";

chapter SNiP III-19-76 "Wooden structures";

SN 393-78 "Instruction for welding reinforcement joints and embedded parts of reinforced concrete structures".

1. GENERAL PROVISIONS

1.1. These norms and rules apply to the production and acceptance of work performed during the construction and reconstruction of enterprises, buildings and structures in all sectors of the national economy:

in the construction of monolithic concrete and reinforced concrete structures from heavy, extra heavy, on porous aggregates, heat-resistant and alkali-resistant concrete, in the performance of shotcrete and underwater concreting;

in the manufacture of prefabricated concrete and reinforced concrete structures in the conditions of a construction site;

during the installation of prefabricated reinforced concrete, steel, wooden structures and structures made of light efficient materials;

when welding assembly joints of building steel and reinforced concrete structures, reinforcement joints and embedded products of monolithic reinforced concrete structures;

in the production of works on the construction of stone and reinforced masonry structures from ceramic and silicate bricks, ceramic, silicate, natural and concrete stones, brick and ceramic panels and blocks, concrete blocks.

The requirements of these rules should be taken into account when designing the structures of buildings and structures.

1.2. The work specified in paragraph 1.1 must be carried out in accordance with the project, as well as comply with the requirements of the relevant standards, building codes and rules for the organization of construction production and safety in construction, fire safety rules for the production of construction and installation works, as well as the requirements of state supervision bodies .

1.3. When erecting special structures - roads, bridges, pipes, tunnels, subways, airfields, hydraulic engineering, reclamation and other structures, as well as when erecting buildings and structures on permafrost and subsidence soils, undermined territories and in seismic areas, it is necessary to additionally be guided by the requirements of the relevant regulatory - technical documents.

1.4. Work on the construction of buildings and structures should be carried out according to the approved project for the production of works (PPR), which, along with the general requirements of SNiP 3.01.01-85, should provide for: the sequence of installation of structures; measures to ensure the required accuracy of the installation; spatial immutability of structures in the process of their pre-assembly and installation in the design position; stability of structures and parts of the building (structure) in the process of construction; the degree of enlargement of structures and safe working conditions.

The combined installation of structures and equipment should be carried out according to the PPR, which contains the procedure for combining work, interconnected schemes of installation tiers and zones, schedules for lifting structures and equipment.

If necessary, as part of the WEP, additional technical requirements should be developed aimed at improving the construction manufacturability of the structures being erected, which should be agreed upon in the prescribed manner with the organization - the project developer and included in the executive working drawings.

1.5. Data on the production of construction and installation works should be entered daily in the work logs for the installation of building structures (mandatory Appendix 1), welding (mandatory Appendix 2), anti-corrosion protection of welded joints (mandatory Appendix 3), embedment of field joints and assemblies (mandatory Appendix 4 ), making field connections on bolts with controlled tension (mandatory Appendix 5), as well as fixing their position on geodetic executive diagrams during the installation of structures.

1.6. Structures, products and materials used in the construction of concrete, reinforced concrete, steel, wood and stone structures must meet the requirements of the relevant standards, specifications and working drawings.

1.7. Transportation and temporary storage of structures (products) in the installation area should be carried out in accordance with the requirements of state standards for these structures (products), and for non-standardized structures (products) the following requirements must be observed:

structures should, as a rule, be in a position corresponding to the design one (beams, trusses, slabs, wall panels, etc.), and if this condition cannot be met, in a position convenient for transportation and transfer to installation (columns, flights of stairs etc.) provided that their strength is ensured;

structures should be based on inventory linings and gaskets of rectangular section, located in the places indicated in the project; the thickness of the gaskets must be at least 30 mm and at least 20 mm higher than the height of the sling loops and other protruding parts of the structures; for multi-tiered loading and storage of the same type of structures, linings and gaskets should be located on the same vertical along the line of lifting devices (loops, holes) or in other places indicated in the working drawings;

structures must be securely fastened to protect against overturning, longitudinal and transverse displacement, mutual impacts against each other or against the structure of vehicles; fastenings should ensure the possibility of unloading each element from vehicles without violating the stability of the rest;

textured surfaces must be protected from damage and contamination;

reinforcement outlets and protruding parts must be protected from damage; factory marking must be accessible for inspection;

small parts for mounting connections should be attached to the shipping elements or sent simultaneously with the structures in a container equipped with tags indicating the brands of the parts and their number; these parts should be stored under a canopy;

fasteners should be stored indoors, sorted by type and brand, bolts and nuts - by strength classes and diameters, and high-strength bolts, nuts and washers - and by lot.

1.8. Structures during storage should be sorted by brands and stacked taking into account the sequence of installation.

1.10. To ensure the safety of wooden structures during transportation and storage, inventory devices (lodgements, clamps, containers, soft slings) should be used with installation of soft pads and linings in places of support and contact of structures with metal parts, and also protect them from exposure to solar radiation, alternate moisture and drying.

1.11. Prefabricated structures should be installed, as a rule, from vehicles or enlargement stands.

1.12. Before lifting each mounting element, check:

compliance with its design brand;

the condition of embedded products and installation marks, the absence of dirt, snow, ice, damage to the finish, priming and painting;

availability of the necessary connecting parts and auxiliary materials at the workplace;

correctness and reliability of fastening of load-handling devices;

as well as to equip, in accordance with the PPR, with scaffolding, ladders and fences.

1.13. Slinging of mounted elements should be carried out in the places indicated in the working drawings, and ensure their lifting and supply to the installation site in a position close to the design one. If it is necessary to change the places of slinging, they must be agreed with the organization - the developer of the working drawings.

It is forbidden to sling structures in arbitrary places, as well as for the release of reinforcement.

Slinging schemes for enlarged flat and spatial blocks should ensure their strength, stability and invariability of geometric dimensions and shapes when lifting.

1.14. Mounted elements should be lifted smoothly, without jerks, swinging and rotation, as a rule, using braces. When lifting vertically located structures, one guy is used, horizontal elements and blocks - at least two.

The structures should be lifted in two stages: first, to a height of 20-30 cm, then, after checking the reliability of the slinging, further lifting should be carried out.

1.15. When installing mounting elements, the following must be ensured:

stability and immutability of their position at all stages of installation;

work safety;

the accuracy of their position with the help of constant geodetic control;

strength of mounting connections.

1.16. Structures should be installed in the design position according to the accepted guidelines (risks, pins, stops, edges, etc.).

Structures with special embedded or other fixing devices should be installed on these devices.

1.17. Mounting elements to be installed must be securely fastened before bridging.

1.18. Until the end of the reconciliation and reliable (temporary or design) fixing of the installed element, it is not allowed to rest on it the overlying structures, if such support is not provided for by the PPR.

1.19. If there are no special requirements in the working drawings, the maximum deviations of the alignment of landmarks (edges or marks) during the installation of prefabricated elements, as well as deviations from the design position of structures completed by installation (erection) should not exceed the values ​​given in the relevant sections of these rules and regulations.

Deviations for the installation of mounting elements, the position of which may change in the process of their permanent fixing and loading with subsequent structures, should be assigned in the PPR so that they do not exceed the limit values ​​after the completion of all installation work. In the absence of special instructions in the PPR, the deviation of the elements during installation should not exceed 0.4 of the maximum deviation for acceptance.

1.20. The use of installed structures for attaching cargo pulley blocks, diverting blocks and other lifting devices to them is allowed only in cases provided for by the PPR and agreed, if necessary, with the organization that completed the working drawings of the structures.

1.21. The installation of building structures (structures) should, as a rule, begin with a spatially stable part: a bond cell, a stiffening core, etc.

Installation of structures of buildings and structures of great length or height should be carried out in spatially stable sections (spans, tiers, floors, temperature blocks, etc.).

1.22. Production quality control of construction and installation works should be carried out in accordance with SNiP 3.01.01-85.

The following documentation must be submitted during acceptance control:

as-built drawings with introduced (if any) deviations, approved by the enterprise - the manufacturer of structures, as well as the installation organization, agreed with the design organizations - developers of the drawings, and documents on their approval;

factory technical passports for steel, reinforced concrete and wooden structures;

documents (certificates, passports) certifying the quality of materials used in the construction and installation works;

certificates of examination of hidden works;

acts of intermediate acceptance of critical structures;

Executive geodetic schemes of the position of structures;

work logs;

documents on quality control of welded joints;

acts of testing structures (if tests are provided for by additional rules of these rules and regulations or working drawings);

other documents specified in additional rules or working drawings.

1.23. It is allowed in projects, with appropriate justification, to assign requirements for the accuracy of parameters, volumes and methods of control that differ from those provided for by these rules. In this case, the accuracy of the geometric parameters of structures should be assigned on the basis of the accuracy calculation in accordance with GOST 21780-83.

2. CONCRETE WORKS

MATERIALS FOR CONCRETE

2.1. The choice of cements for the preparation of concrete mixtures should be made in accordance with these rules (recommended Appendix 6) and GOST 23464-79. Acceptance of cements should be carried out in accordance with GOST 22236-85, transportation and storage of cements - in accordance with GOST 22237-85 and SNiP 3.09.01-85.

2.2. Aggregates for concrete are used fractionated and washed. It is forbidden to use a natural mixture of sand and gravel without sieving into fractions (mandatory Appendix 7). When choosing aggregates for concrete, mainly materials from local raw materials should be used. To obtain the required technological properties of concrete mixtures and the performance properties of concrete, chemical additives or their complexes should be used in accordance with the mandatory Appendix 7 and the recommended Appendix 8.

CONCRETE MIXTURES

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

2.4. The order of loading the components, the duration of mixing the concrete mixture should be established for specific materials and conditions of the concrete mixing equipment used by evaluating the mobility, uniformity and strength of concrete in a particular batch. When introducing segments of fibrous materials (fibers), such a method of their introduction should be provided so that they do not form lumps and inhomogeneities.

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

water, part of the sand, finely ground mineral filler (if used) and cement are dosed into a working high-speed mixer, where everything is mixed;

the resulting mixture is fed into a concrete mixer, pre-loaded with the rest of the aggregates and water, and once again everything is mixed.

2.5. Transportation and supply of concrete mixtures should be carried out by specialized means that ensure the preservation of the specified properties of the concrete mixture. It is forbidden to add water at the place 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.

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

Table 1

LAYING CONCRETE MIXTURES

2.8. Before concreting, rock foundations, horizontal and inclined concrete surfaces of working joints must be cleaned of debris, dirt, oils, snow and ice, cement film, etc. Immediately before laying the concrete mix, the cleaned surfaces must be washed with water and dried with a jet of air.

2.9. All structures and their elements closed in the course of subsequent work (prepared structural bases, reinforcement, embedded products, etc.), as well as the correct installation and fixing of the formwork and its supporting elements, must be accepted in accordance with SNiP 3.01.01-85.

2.10. Concrete mixtures should be laid in concreted structures in horizontal layers of the same thickness without gaps, with consistent direction of laying in one direction in all layers.

2.11. When compacting the concrete mixture, it is not allowed to rest the vibrators on the reinforcement and embedded products, strands and other elements of the formwork fastening. The depth of immersion of the deep vibrator in the concrete mixture should ensure its deepening into the previously laid layer by 5 - 10 cm.

2.12. Laying of the next layer of concrete mixture is allowed before the beginning of setting of the concrete of the previous layer. The duration of the break between the laying of adjacent layers of concrete mix without the formation of a working seam is established by the construction laboratory. The top level of the laid concrete mixture should be 50 - 70 mm below the top of the formwork panels.

2.13. The surface of the working joints, arranged when laying the concrete mixture intermittently, should be perpendicular to the axis of the columns and beams to be concreted, the surface of the slabs and walls. The resumption of concreting is allowed to be carried out when the concrete reaches a strength of at least 1.5 MPa. Working seams, in agreement with the design organization, can be arranged during concreting:

columns - at the level of the top of the foundation, the bottom of the runs, beams and crane consoles, the top of the crane beams, the bottom of the capitals of the columns;

beams of large dimensions, monolithically connected to the slabs - 20 - 30 mm below the mark of the lower surface of the slab, and if there are haunches in the slab - at the mark of the bottom of the haunch of the slab;

flat slabs - anywhere parallel to the smaller side of the slab;

ribbed floors - in the direction parallel to the secondary beams;

individual beams - within the middle third of the span of beams, in the direction parallel to the main beams (girders) within two middle quarters of the span of girders and slabs;

massifs, arches, vaults, reservoirs, bunkers, hydraulic structures, bridges and other complex engineering structures and structures - in the places specified in the projects.

2.14. Requirements for laying and compaction of concrete mixes are given in Table. 2.

table 2

CURATING AND CARE OF CONCRETE

2.15. In the initial period of hardening, concrete must be protected from atmospheric precipitation or moisture loss, and subsequently, the temperature and humidity conditions must be maintained with the creation of conditions that ensure an increase in its strength.

2.16. Measures for the care of concrete, the procedure and timing of their implementation, control over their implementation and the timing of the stripping of structures should be established by the PPR.

2.17. The movement of people on concreted structures and the installation of formwork of overlying structures are allowed after the concrete reaches a strength of at least 1.5 MPa.

CONCRETE TESTING DURING ACCEPTANCE OF STRUCTURES

2.18. Strength, frost resistance, density, water resistance, deformability, as well as other indicators established by the project, should be determined in accordance with the requirements of current state standards.

CONCRETE ON POROUS AGGREGATES

2.19. Concrete must meet the requirements of GOST 25820-83.

2.20. Materials for concrete should be selected in accordance with the mandatory Appendix 7, and chemical additives - with the recommended Appendix 8.

2.21. The selection of concrete composition should be made in accordance with GOST 27006-86.

2.22. Concrete mixtures, their preparation, delivery, laying and care of concrete must meet the requirements of GOST 7473-85.

2.23. The main indicators of the quality of the concrete mixture and concrete should be controlled in accordance with Table. 3.

Table 3

ACID AND ALKALI RESISTANT CONCRETE

2.24. Acid-resistant and alkali-resistant concretes must comply with the requirements of GOST 25192-82. The compositions of acid-resistant concretes and the requirements for materials are given in Table. 4

Table 4

2.25. The preparation of concrete mixtures on liquid glass should be carried out in the following order. The hardening initiator, filler and other powdered components sifted through a No. 03 sieve are mixed dry in a closed mixer beforehand. Liquid glass is mixed with modifying additives. First, crushed stone of all fractions and sand are loaded into the mixer, then a mixture of powdered materials and mixed for 1 minute, then liquid glass is added and mixed for 1-2 minutes. In gravity mixers, the mixing time of dry materials is increased to 2 minutes, and after loading all the components - up to 3 minutes. Adding liquid glass or water to the finished mixture is not allowed. The viability of the concrete mixture is no more than 50 minutes at 20 degrees C, it decreases with increasing temperature. Requirements for the mobility of concrete mixtures are given in table. 5.

2.26. Transportation, laying and compaction of the concrete mixture should be carried out at an air temperature of at least 10 degrees C within a period not exceeding its viability. Laying must be carried out continuously. When arranging a working joint, the surface of the hardened acid-resistant concrete is notched, dedusted and primed with liquid glass.

2.27. The moisture content of the surface of concrete or brick protected by acid-resistant concrete should be no more than 5% by weight, at a depth of up to 10 mm.

2.28. The surface of reinforced concrete structures made of concrete on Portland cement before laying acid-resistant concrete on them must be prepared in accordance with the instructions of the project or treated with a hot solution of magnesium silicofluoride (3-5% solution at a temperature of 60 degrees C) or oxalic acid (5-10% solution) or primed with polyisocyanate or 50% polyisocyanate solution in acetone.

Table 5

2.29. The concrete mixture on liquid glass should be compacted by vibrating each layer with a thickness of not more than 200 mm for 1-2 minutes.

2.30. Hardening of concrete within 28 days should occur at a temperature not lower than 15 degrees C. Drying is allowed with the help of air heaters at a temperature of 60-80 degrees C during the day. Temperature rise rate - no more than 20-30 °С/h.

2.31. The acid resistance of acid-resistant concrete is ensured by the introduction of polymer additives of 3-5% by weight of liquid glass into the concrete composition: furyl alcohol, furfural, furitol, acetone-formaldehyde resin ACF-3M, tetrafurfuryl ether of orthosilicic acid TFS, a compound of furyl alcohol with phenol-formaldehyde resin FRV-1 or FRV- 4.

2.32. The water resistance of acid-resistant concrete is ensured by introducing into the composition of concrete finely ground additives containing active silica (diatomite, tripoli, aerosil, flint, chalcedony, etc.), 5-10% of the mass of liquid glass or polymer additives up to 10-12% of the mass of liquid glass: polyisocyanate, carbamide resin KFZh or KFMT, organosilicon hydrophobizing liquid GKZH-10 or GKZH-11, paraffin emulsion.

2.33. The protective properties of acid-resistant concrete in relation to steel reinforcement are provided by the introduction of corrosion inhibitors into the concrete composition of 0.1-0.3% of the mass of liquid glass: lead oxide, a complex additive of catapine and sulfonic acid, sodium phenylanthranilate.

2.34. Demoulding of structures and subsequent processing of concrete is allowed when the concrete reaches 70% of the design strength.

2.35. An increase in the chemical resistance of structures made of acid-resistant concrete is provided by double surface treatment with a solution of sulfuric acid of 25-40% concentration.

2.36. Materials for alkali-resistant concretes in contact with alkali solutions at temperatures up to 50 degrees C must meet the requirements of GOST 10178-85. The use of cements with active mineral additives is not allowed. The content of granulated or electrothermophosphoric slags must be at least 10 and not more than 20%. The content of the mineral C(3)A in Portland cement and Portland slag cement should not exceed 8%. The use of aluminous binder is prohibited.

2.37. Fine aggregate (sand) for alkali-resistant concrete, operated at temperatures up to 30 degrees C, should be used in accordance with the requirements of GOST 10268-80, above 30 degrees C - crushed from alkali-resistant rocks - limestone, dolomite, magnesite, etc. n. Coarse aggregate (crushed stone) for alkali-resistant concrete, operated at temperatures up to 30 degrees C, should be used from dense igneous rocks - granite, diabase, basalt, etc.

2.38. Crushed stone for alkali-resistant concrete, operated at temperatures above 30 degrees C, should be used from dense carbonate sedimentary or metamorphic rocks - limestone, dolomite, magnesite, etc. The water saturation of crushed stone should be no more than 5%.

HEAT-RESISTANT CONCRETE

2.39. Materials for the preparation of ordinary concrete, operated at temperatures up to 200 degrees C, and heat-resistant concrete should be used in accordance with the recommended Appendix 6 and the mandatory Appendix 7.

2.40. Dosing of materials, preparation and transportation of concrete mixtures must meet the requirements of GOST 7473-85 and GOST 20910-82.

2.41. An increase in the mobility of concrete mixes for ordinary concretes operated at temperatures up to 200 degrees C is allowed through the use of plasticizers and superplasticizers.

2.42. The use of chemical hardening accelerators in concretes operated at temperatures above 150 degrees C is not allowed.

2.43. Concrete mixtures should be laid at a temperature not lower than 15 degrees C, and this process should be continuous. Breaks are allowed in the places where working or expansion joints are provided for by the project.

2.44. Hardening of concretes on a cement binder should occur under conditions that ensure the wet state of the concrete surface.

Hardening of concrete on liquid glass should occur in an air-dry environment. During the hardening of these concretes, good air ventilation must be provided to remove water vapor.

2.45. Drying and heating of heat-resistant concrete should be carried out in accordance with the PPR.

EXTREMELY HEAVY CONCRETE AND FOR RADIATION PROTECTION

2.46. Works with the use of especially heavy concretes and concretes for radiation protection should be carried out according to the usual technology. In cases where conventional concreting methods are inapplicable due to mixture stratification, complex configuration of the structure, saturation with reinforcement, embedded parts and communication penetrations, the method of separate concreting should be used (rising mortar method or method of coarse aggregate embedding into the mortar). The choice of concreting method should be determined by the WEP.

2.47. The materials used for radiation protection concretes must comply with the requirements of the project.

2.48. Requirements for the granulometric composition, physical and mechanical characteristics of mineral, ore and metal aggregates must comply with the requirements for aggregates for heavy concrete. Metal fillers must be degreased before use. Non-peeling rust is allowed on metal aggregates.

2.49. Passports for materials used for the manufacture of radiation protection concretes must contain data on a complete chemical analysis of these materials.

2.50. Works with the use of concrete on metal aggregates are allowed only at positive ambient temperatures.

2.51. When laying concrete mixtures, it is prohibited to use belt and vibration conveyors, vibrating bunkers, vibroshoes, dropping of a particularly heavy concrete mixture is allowed from a height of not more than 1 m.

2.52. Concrete testing should be carried out in accordance with clause 2.18.

PRODUCTION OF CONCRETE WORKS

AT NEGATIVE AIR TEMPERATURES

2.53. These rules shall be complied with during the period of concrete work with the expected average daily outdoor temperature below 5 degrees C and the minimum daily temperature below 0 degrees C.

2.54. The preparation of the concrete mixture should be carried out in heated concrete mixing plants, using heated water, thawed or heated aggregates, ensuring the production of a concrete mixture with a temperature not lower than that required by the calculation. It is allowed to use unheated dry aggregates that do not contain frost on grains and frozen clods. At the same time, the duration of mixing the concrete mixture should be increased by at least 25% compared to summer conditions.

2.55. Methods and means of transportation should ensure that the temperature of the concrete mixture does not drop below the required one by calculation.

2.56. The condition of the base on which the concrete mixture is laid, as well as the temperature of the base and the laying method, must exclude the possibility of freezing of the mixture in the zone of contact with the base. When curing concrete in a structure by the thermos method, when preheating the concrete mixture, as well as when using concrete with antifreeze additives, it is allowed to lay the mixture on an unheated, non-porous base or old concrete, if, according to the calculation, in the contact zone during the estimated period of curing the concrete does not freeze. At air temperatures below minus 10 degrees C, concreting of densely reinforced structures with reinforcement with a diameter of more than 24 mm, reinforcement from rigid rolled profiles or with large metal embedded parts should be carried out with preliminary heating of the metal to a positive temperature or local vibration of the mixture in the reinforcement and formwork zones, after with the exception of cases of laying preheated concrete mixtures (at a mixture temperature above 45 degrees C). The duration of vibrating the concrete mixture should be increased by at least 25% compared to summer conditions.

2.57. When concreting elements of frame and frame structures in structures with rigid coupling of nodes (supports), the need for gaps in spans, depending on the heat treatment temperature, taking into account the resulting thermal stresses, should be agreed with the design organization. Unformed surfaces of structures should be covered with vapor and heat insulating materials immediately after concreting.

Reinforcement outlets of concreted structures must be covered or insulated to a height (length) of at least 0.5 m.

2.58. Before laying the concrete (mortar) mixture, the surfaces of the cavities of the joints of prefabricated reinforced concrete elements must be cleared of snow and ice.

2.59. Concreting of structures on permafrost soils should be carried out in accordance with SNiP II-18-76.

Acceleration of concrete hardening when concreting monolithic bored piles and embedding bored piles should be achieved by introducing complex antifreeze additives into the concrete mixture that do not reduce the freezing strength of concrete with permafrost soil.

2.60. The choice of concrete curing method for winter concreting of monolithic structures should be made in accordance with the recommended Appendix 9.

2.61. The control of the strength of concrete should be carried out, as a rule, by testing samples made at the place of laying the concrete mixture. Samples stored in frost should be kept for 2-4 hours at a temperature of 15-20 degrees C before testing.

It is allowed to control the strength by the temperature of the concrete during its curing.

2.62. Requirements for the production of work at negative air temperatures are set in Table. 6

DEVELOPED BY TsNIIOMTP Gosstroy of the USSR (Doctor of Technical Sciences V. D. Topchiy; Candidates of Technical Sciences Sh. L. Machabeli, R. A. Kagramanov, B. V. Zhadanovsky, Yu. B. Chirkov, V. V. Shishkin , N. I. Evdokimov, V. P. Kolodiy, L. N. Karnaukhova, I. I. Sharov, Doctor of Technical Sciences K. I. Bashlay, A. G. Prozorovsky); NIIZHB Gosstroy of the USSR (Doctor of Technical Sciences B. A. Krylov; Candidates of Technical Sciences O. S. Ivanova, E. N. Malinsky, R. K. Zhitkevich, B. P. Goryachev, A. V. Lagoida, N. K. Rozental, N. F. Shesterkina, A. M. Fridman, V. V. Zhukov, Doctor of Technical Sciences); VNIPIPromstalkonstruktsiya Minmontazhspetsstroy of the USSR (B. Ya. Moyzhes, B. B. Rubanovich), TsNIISK im. Kucherenko of the Gosstroy of the USSR (Doctor of Technical Sciences L. M. Kovalchuk; Candidates of Technical Sciences V. A. Kameiko, I. P. Preobrazhenskaya; L. M. Lomova); V. G. Kravchenko, Technical Sciences); VNIIMontazhspetsstroy of the Ministry of Montazhspetsstroy of the USSR (G. A. Ritchik); TsNIIEP housing of the State Committee for Architecture (S. B. Vilensky) with the participation of the Donetsk Promstroyniiproekt, the Krasnoyarsk Promstroyniiproekt of the Gosstroy of the USSR; Gorky Engineering and Construction Institute. Chkalov of the USSR State Committee for Public Education; VNIIG them. Vedeneev and Orgenergostroy of the Ministry of Energy of the USSR; TsNIIS of the Ministry of Transport of the USSR; Aeroproject Institute of the USSR Ministry of Civil Aviation; NIIMosstroy of the Moscow City Executive Committee.

INTRODUCED by TsNIIOMTP Gosstroy of the USSR.

PREPARED FOR APPROVAL by the Department of Standardization and Technical Standards in Construction of the USSR State Construction Committee (A. I. Golyshev, V. V. Bakonin, D. I. Prokofiev).

With the entry into force of SNiP 3.03.01-87 "Bearing and enclosing structures" lose their force:

chapter SNiP III-15-76 "Monolithic concrete and reinforced concrete structures";

SN 383-67 "Instructions for the production and acceptance of work during the construction of reinforced concrete tanks for oil and oil products";

chapter SNiP III-16-80, "Concrete and reinforced concrete prefabricated structures";

SN 420-71 "Guidelines for sealing joints during installation of building structures";

chapter SNiP III-18-75 "Metal structures" in terms of installation of structures";

clause 11 “Changes and additions to the chapter SNiP III-18-75 “Metal structures”, approved by the Decree of the USSR Gosstroy dated April 19, 1978 No. 60;

chapter SNiP III-17-78 "Stone structures";

chapter SNiP III-19-76 "Wooden structures";

SN 393-78 "Instruction for welding joints of reinforcement and embedded parts of reinforced concrete structures."

When using a regulatory document, one should take into account the approved changes in building codes and regulations and state standards published in the Bulletin of Construction Equipment magazine, the Collection of Changes to Building Codes and Rules of the USSR Gosstroy and the information index "State Standards of the USSR" of the USSR State Standard.