GOST 8717.0-84 Reinforced concrete and concrete steps. Specifications

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We have previously considered the provisions of GOST 231202016 “Flying stairs, platforms and steel fences”, which replaced GOST 9818-85. They discuss the general requirements for flights of stairs, but there is another regulatory act, the name of which speaks for itself. We are talking about GOST 8717.1-84 “Reinforced concrete and concrete steps. Designs and Dimensions" is a very important document, especially considering that the installation of concrete stairs is now more often chosen than the installation of stepped structures made of other materials. This is primarily due to the unique characteristics of reinforced concrete.

TYPES, MAIN PARAMETERS AND DIMENSIONS

1.1. Steps, depending on their shape and location in the flight of stairs, are divided into the following types:

LS - main;

LSV - upper frieze;

LSP - platform liner;

LSN - lower frieze;

LSS - flat for through marches.

Layout diagrams of steps in a flight of stairs are given in the reference appendix.

1.2. The shape and dimensions of the steps, as well as their material consumption indicators, must correspond to those indicated in the drawing. 1, 2 and in table. 1.

1.3. The steps are made of reinforced concrete.

The main steps (LS type) with a length of up to 1500 mm inclusive for stairs arranged on a solid base are made of concrete.

1
-
“bed”;
2
- “tail”

The size in brackets refers to steps for stairs with a slope of 1:1.5.

Crap. 1

1.4. Reinforced concrete steps are intended for use in stairs with a calculated short-term load (without taking into account their own weight) up to 6 kPa (600 kgf/m2).

1.5. The steps are made with embedded products for fastening the fences.

Steps can be manufactured with sockets (instead of embedded products) for fastening fences, if this is indicated in the order for the manufacture of steps.

In flat steps (LSS type), embedded products are installed for fastening to stringers with a width of at least 155 mm and no more than 180 mm, while the axes of symmetry of the embedded products of steps and stringers must coincide.

It is allowed to install additional embedded products in the steps in accordance with the design of a specific building or structure.

1.6. Steps, if necessary, are made in two versions: right and left - for stairs with rise, respectively, counterclockwise and clockwise.

Stages of standard sizes LSS12 and LSS15

Crap. 2

1.7. The steps are made with mounting loops.

The manufacture of steps without mounting loops and the use of gripping devices for lifting them is permitted by agreement between the manufacturer, the consumer and the design organization - the author of the building or structure project.

1.8. Steps made of heavy concrete and dense silicate concrete are made with or without a decorative structural layer of concrete on the upper front surface.

Steps made of lightweight concrete must have a top layer of heavy concrete with a thickness of at least 15 mm or a decorative structural layer or a coating of abrasion-resistant synthetic materials.

1.9. The decorative structural layer of the steps must have a thickness of at least 15 mm and be made of heavy concrete or dense silicate concrete.

Table 1

Notes:

. The brands of steps in the table are given without indicating the version of the steps (clause 1.6).

. Steps with a height of 125 and 145 mm are intended for stairs with a slope of 1:2, and steps with a height of 143 and 168 mm are intended for stairs with a slope of 1:1.5 (for basements, attics and other service stairs).

. Steel consumption is indicated: in the numerator - for a step with mounting loops, in the denominator - for a step without mounting loops.

In the case of installing nests in the steps (instead of embedded products) for fastening fences or installing additional embedded products (clause 1.5), the steel consumption per step is indicated in the table. , should be changed accordingly.

. The weight of the steps is given for steps made of heavy concrete with an average density of 2400 kg/m3, for steps made of lightweight concrete and dense silicate concrete - 1800 kg/m3.

. It is allowed to manufacture steps with dimensions different from those indicated in the table. , on existing equipment before January 1, 1988

1.10. Depending on the finishing of the upper front surfaces, the steps are manufactured in the following types:

with a smooth concrete surface using ordinary cement;

with a smooth surface of a decorative structural layer on white or colored cement;

with a polished mosaic surface of a decorative structural layer of concrete on regular, white or colored cement and on crushed marble.

The visible bottom and end surfaces of the steps are intended for painting.

1.11. To increase wear resistance and reduce the slipperiness of steps, it is allowed to install separate inserts made of friction and abrasion-resistant materials in the form of strips embedded in the step during its molding.

1.12. The designs of steps, as well as reinforcement and embedded products for them, are given in GOST 8717.1-84.

1.13. Steps should be marked with marks in accordance with the requirements of GOST 23009-78.

The step brand consists of alphanumeric groups separated by hyphens.

The first group contains the designation of the type of step and overall dimensions (the values ​​of which are rounded to a whole number): the length of the step or the width of the flight of stairs (for steps of the LSV type), and steps with a height of 168 or 143 mm and their height in centimeters.

In the second group indicate:

for steps made of lightweight concrete and dense silicate concrete - the type of concrete, designated by capital letters L and S, respectively;

for concrete main steps (type LS) - capital letter B.

In the third group (or in the second group if the designations of the stage characteristics given in this brand group are absent) indicate:

the presence of embedded products or nests in the step (clause 1.5), indicated by Arabic numerals: 1 - for steps with embedded products in accordance with GOST 8717.1-84; 2, 3, etc. - for steps with additional embedded products or sockets in accordance with the design documentation of a specific building or structure;

the left version of the step (clause 1.6), denoted by the lowercase letter “l”;

type of finishing of the upper front surface of the step (with the exception of the smooth surface of concrete on ordinary cement, which is not indicated in the brand), denoted by the capital letter G for a smooth surface of the decorative structural layer of concrete on white or colored cement, Ш - for a polished mosaic surface;

additional characteristics that ensure the durability of the steps under operating conditions. For example: M - for steps used in areas with a design outdoor temperature below minus 40 ° C; for steps used in conditions of exposure to aggressive environments - characteristics of the degree of concrete density. (For example, P - high density).

An example of a symbol (brand) for a LS type step, 1500 mm long, 145 mm high, made of heavy concrete, with embedded products for fastening the fence, with a smooth surface of a decorative structural layer of concrete on white cement, intended for stairs with a clockwise rise:

LS 15-1Gl

The same, LS type steps 1200 mm long, 168 mm high, made of heavy concrete, with a smooth upper front surface of concrete on ordinary cement:

LS12.17

The same, LSV type steps 1310 mm long (designed for marches 1200 mm wide), 145 mm high, made of lightweight concrete, with a polished mosaic surface of a decorative structural layer of concrete on colored cement and crushed marble:

LSV12-L-SH

TECHNICAL REQUIREMENTS

2.1. The steps should be manufactured in accordance with the requirements of this standard and technological documentation approved in the prescribed manner, according to the drawings given in GOST 8717.1-84.

2.2. The steps must meet the requirements of GOST 13015.0-83:

according to factory readiness;

in terms of strength and crack resistance;

according to the actual strength of concrete (at design age and tempering age);

on frost resistance, water resistance and abrasion of concrete;

to the quality of materials used to prepare concrete;

to concrete, as well as to materials for preparing concrete steps used under conditions of exposure to aggressive environments;

to the quality of reinforcement and embedded products and their position in the steps;

to steel grades for reinforcing and embedded products, including for mounting hinges;

by deviation of the thickness of the protective layer of concrete;

on the use of molds for the manufacture of steps.

2.3. Steps should be made of concrete of the compressive strength class:

B25 - steps for external stairs of buildings and structures, as well as steps made of heavy concrete or dense silicate concrete, intended for internal stairs of residential buildings up to 5 floors high;

B15 - steps for other buildings and structures.

The top concrete layer of steps made of lightweight concrete, as well as the decorative structural layer of steps should be made of heavy concrete or dense silicate concrete of compressive strength class B25.

The type of concrete and its compressive strength class must correspond to those specified in the order for the manufacture of steps.

2.4. The coefficient of variation in the compressive strength of concrete in a batch for steps of the highest quality category should not be more than:

9% - for heavy and light concrete;

10% - for dense silicate concrete.

2.5. The value of the standardized tempering strength of concrete steps as a percentage of the concrete class for compressive strength should be taken equal to:

70 - for steps made of heavy or light concrete;

100 - for steps made of dense silicate concrete.

When delivering steps in the cold season, it is allowed to increase the value of the standardized tempering strength of concrete, but not more than 85% of the compressive strength class. The value of the standardized tempering strength of concrete should be taken according to the design documentation for a specific building or structure in accordance with the requirements of GOST 13015.0-83.

(Changed edition, Amendment No. 1).

2.6. The average density of lightweight concrete and dense silicate concrete (in a dried to constant weight state) should not be less than 1800 kg/m3.

2.7. The abrasion of the decorative structural layer of concrete on crushed marble should not exceed 1.8 g/cm2.

The abrasion of the decorative structural layer of concrete steps of the highest quality category should not exceed 1.6 g/cm2.

2.8. The shape and dimensions of welded reinforcing mesh and embedded products and their position in the steps must comply with those established in GOST 8717.1-84.

The shape and dimensions of additional embedded products (clause 1.5) and their position in the steps must correspond to those specified in the design documentation of the building or structure.

2.9. Reinforcing steels must meet the requirements of state standards:

rod reinforcing steel classes A-I and A-III - GOST 5781-82;

reinforcing wire class VR-I - GOST 6727-80.

2.10. Reinforcement in steps made of dense silicate concrete intended for use in rooms with a relative humidity of internal air above 60% or in unheated buildings (structures) and outdoors in normal and humid humidity zones should be protected from corrosion. The method of protecting the reinforcement must comply with that established by the design documentation (in accordance with the requirements of SN 165-76) and specified in the order for the manufacture of steps.

2.11. The open surfaces of steel embedded products must have an anti-corrosion coating, the type and technical characteristics of which must correspond to those established by the design of the building or structure in accordance with the requirements of SNiP 2.03.11-85 and specified in the order for the manufacture of steps.

(Changed edition, Amendment No. 1).

2.12. The values ​​of actual deviations of the geometric parameters of the steps should not exceed the limits specified in the table. 2.

table 2

2.13. Categories of concrete step surfaces:

front polished mosaic - A0 or A1;

facial smooth - A1 or A2;

front, intended for painting - A3;

non-facial, not visible under operating conditions - A7.

Requirements for the quality of surfaces and the appearance of steps are in accordance with GOST 13015.0-83 and this standard.

2.13.1. The upper front surface of the steps of the batch must have the same color and tone.

The surface of the mosaic decorative structural layer must have a uniform (or as specified in the design documentation and order) distribution of marble crushed stone. In the first case, areas without marble crushed stone with an area of ​​more than 3 cm2 are not allowed.

2.13.2. Cracks in concrete are not allowed on the surfaces of the steps, with the exception of shrinkage and other local surface technological cracks with a width of no more than 0.1 mm on the bottom and end surfaces of the steps.

2.13.3. Steps of the highest quality category must have a polished mosaic or smooth top surface of category A1.

Short description

Solid flights of stairs and precast concrete elements are made from light or heavy medium-density cement composite. Corrugated metal rods and steel wire are used for the reinforcing frame.

Structurally finished products are represented by a load-bearing base and steps. At large facilities, marches with one or two adjacent platforms are used. In the absence of the latter, special frieze elements (steps) are provided in the end part. They are needed for fastening individual elements of a flight of stairs.

Physical parameters

The dimensions of reinforced concrete staircases are standardized, which simplifies the work of designers. All parameters are calculated based on the human factor: average step, height, reach.

The table shows the basic indicators for each structural element:

The weight of a reinforced concrete flight of stairs depends on the physical parameters of the finished product and the design of the span:

• platforms, half-courts, friezes;
• type of support base for steps;
• the presence or absence of treads (overlay element for mechanical protection of the step).

Weight of flights of stairs 9,11,12 steps

There is a dependence on the brand of concrete used to form a reinforced monolith. On average, to determine the weight of a reinforced concrete flight of stairs (for example, 9 steps), a mass of 95 kg is considered. Here we take into account a sample with a width of 33 cm, a height of 14.5 cm, and a length of 0.9 m. That is, the entire product will weigh almost 850 kg.

Let's calculate the weight of a flight of reinforced concrete stairs for 11 steps, if the size of each is as follows: 100 * 33 * 14.5 cm. Here the weight will average about 104 kg. We get a product weighing 1145 kg.

Standard indicators also include:

• LS-11 (105*33*14.5 cm) - 115 kg;
• LS-12 (120*33*14.5 cm) - 133 kg;
• LS-14 (135*33*14.5 cm) - 150 kg.

Based on ready-made data, it is possible to make preliminary calculations of the weight for the required reinforced concrete flight of stairs. Thus, 12 stages corresponding to the listed samples can have a total mass of 1380, 1596 kg or 1.8 tons.

ACCEPTANCE RULES

3.1. Acceptance of steps should be carried out in batches in accordance with the requirements of GOST 13015.1-81 and this standard.

3.2. Acceptance of steps in terms of their strength and crack resistance, frost resistance, water resistance and abrasion of concrete should be carried out based on the results of periodic tests.

3.3. Acceptance of steps in terms of strength (class of compressive strength, tempering strength) and average density of concrete, compliance of reinforcement and embedded products with the requirements of GOST 8717.1-84, strength of welded joints, accuracy of geometric parameters, thickness of the protective layer of concrete to the reinforcement, opening width of shrinkage cracks , categories of concrete surfaces should be made based on the results of acceptance tests and inspections.

3.3.1. In cases where the inspection determines that the actual tempering strength of the concrete is lower than the required tempering strength, the steps should be delivered to the consumer after the concrete reaches a strength corresponding to the class of concrete in terms of compressive strength.

3.3.2. When accepting steps based on the accuracy of geometric parameters, the opening width of shrinkage cracks, and the category of concrete surface, selective single-stage control should be used.

Why choose concrete for the installation of stairs?

Installation of stairs is a very important task, given the importance of stepped structures designed to ensure safe movement on inclined surfaces. This is especially important when arranging the entrance area, where the reliability of the structure and the safety of people depend on the correct installation of the porch. Various options are considered as source material:

• tree;
• rolled metal;
• brick and other piece materials;
• artificial and natural stone;
• reinforced concrete.

Each of the listed materials is good in its own way, especially if its installation was carried out in compliance with the requirements of GOST and SP, where the Code of Rules SP 59.13330.2016 “Accessibility of buildings and structures for people with limited mobility” deserves special attention. This document addresses, among other things, the safety requirements for stairs intended for the movement of disabled people. However, they also have their shortcomings. So, wood is not the best solution for the street, metal stairs are noisy, and granite and marble are expensive.

The ideal solution seems to be the installation of concrete stairs. It is durable, water- and frost-resistant, and also plastic, which is important from a design point of view. The reliability of the structure depends on the composition of the reinforced concrete and the skill of the installers, and the safety of people on the accuracy of the calculations and the correct choice of the size of the steps. That is why we decided to consider the provisions of GOST 8717.1-84.

LABELING, TRANSPORTATION AND STORAGE

5.1. Marking of steps - according to GOST 13015.2-81. Markings and signs should be applied to the non-facing surfaces of steps.

It is allowed, by agreement between the manufacturer and the consumer and the design organization - the author of the project for a specific building or structure, instead of marks, to apply their abbreviated symbols adopted in the design documentation to the steps.

5.2. Requirements for the document on the quality of steps supplied to the consumer are in accordance with GOST 13015.3-81.

5.3. The steps should be transported and stored in accordance with the requirements of GOST 13015.4-84 of this standard.

5.3.1. Steps should be transported and stored in containers or bags.

It is allowed to store steps and transport them without the use of containers. In this case, the steps should be stacked close to one another. Pads under the bottom row of steps and spacers between the rows must be laid at a distance of 200 mm from the ends or in the locations of the mounting loops. The number of rows of steps in a stack should not exceed five.

5.3.2. When transporting, steps should be laid in correct rows with the longitudinal axis in the direction of vehicle movement.

5.3.3. Load slings and other load-handling devices used for loading, unloading and storing steps must have a soft coating in the places where they come into contact with the steps.