Reinforced concrete steps: GOST and features of different designs

Staircase made of prefabricated reinforced concrete steps How we want our house to be beautiful not only in the design sketch. At the building design stage, the architect allocates space for stairs to each subsequent floor. If you have decided to install reinforced concrete steps in your home, your architect-designer will design the stairs in full compliance with building codes. It also doesn’t hurt you to be savvy in this matter. What does it mean to have a reinforced concrete staircase designed and installed according to all standards? What regulatory documents determine the requirements for reinforced concrete (RC) stairs? What does this ladder consist of and how is it installed? What do you need to know to supervise the work of the installation team? We will try to answer all these questions. First of all, you should decide whether your transition to the upper floor will consist of monolithic flights or stacked steps. The first option is used mainly in the construction of multi-storey residential, administrative or commercial buildings. In private construction, the installation of individual reinforced concrete steps on load-bearing inclined foundations is more often used.

Support base for reinforced concrete stairs

They are installed between floors or platforms for turning/turning while moving. The load-bearing foundations for reinforced concrete steps are called stringers. Stringer is the general name for a load-bearing inclined support located under the steps.

Metal stringer

Since reinforced concrete structures are quite heavy, stringers must be made of reinforced concrete or metal. Only these two structural materials can withstand the load of a concrete staircase. I-beams or channels are used as metal stringers. Platforms and stringers are assembled by welding or bolting. The supporting horizontal beams of the platforms rest either on the wall or on their own supporting frame.

Important! The length of the future march should be approximately one and a half to two times the height between the platforms/floors. Only with such an inclination of the stringers will it be possible to install reinforced concrete steps.

1. Length of flight of stairs;
2. Landing Why is it so important to maintain the angle of inclination of the stringers? If the ratio of the span height to its length is 1/2 or 1/1.5, steps made in accordance with GOST can be assembled. According to it, the production of reinforced concrete steps is possible in two types - with a riser height of 145 mm and 168 mm. Prefabricated stairs made from individual reinforced concrete steps can be installed indoors and outdoors. Only if the angle of inclination of the load-bearing stringers is observed is it possible to lay standard reinforced concrete steps.

Reinforced concrete steps according to standard

Reinforced concrete steps must be reliable, comfortable when walking and have high performance properties. Their production is carried out in strict accordance with the requirements of GOST 8717.0-84. It was developed by the USSR State Committee for Construction and came into force on January 1, 1986. Failure to comply with its requirements is fraught with the risk of human life and is punishable by law. This standard is still used for concrete and reinforced concrete steps installed on a continuous inclined base.

When installing stairs, you should use only those steps that meet the requirements of GOST

According to the standard, stacked stairs are assembled indoors and outdoors, with and without heating. Their installation is provided in areas with the lowest temperature of -40°C and maximum seismic activity of up to 9 points on the Richter scale. For installation in worse conditions, as well as in places where aggressive chemicals are present, such ladders must be manufactured to special order. Adhering to the rules of the standard, set-up steps made of reinforced concrete of the highest and first degree of quality are made from light, heavy and silicate concrete mixtures.

How to buy reinforced concrete products of type LS?

Operating in the Moscow region, the ZHBI-4 plant offers the purchase of reinforced concrete products for stairs to clients from a variety of regions, regardless of the specific parameters of the stairs that will be built at their sites.

The proposed reinforced concrete steps are manufactured in accordance with current construction standards, which must be taken into account when drawing up design and estimate documentation. So, by indicating to the company manager by phone or in an online application the markings of the required concrete products, you can make a preliminary calculation and receive an invoice for payment without coming to us. After the funds have been transferred in full, the concrete products indicated in the invoice are reserved in the warehouse.

When collaborating with the ZhBI-4 plant, you can always count on timely and uninterrupted delivery of orders directly to the site and the ability to complete all the necessary concrete products for the project in one place.

Shapes and sizes

The shape of reinforced concrete steps depends on the position on the flight of stairs. A step intended for the middle of a flight cannot begin or end a flight of stairs. Depending on the purpose, there are five types of forms of reinforced concrete steps:

• LS is the main type of stair steps. It is used when filling the main part of the span. If you look at the section, its triangular shape has grooves for connecting the steps to each other.
• LSP – platform liner. He does not participate in the formation of the flight of stairs;
• LSN – lower frieze step. Installed at the base of the march. It is made in the form of a hook, which hooks onto the base of the platform when viewed in section. It takes on the load of the entire staircase and distributes it evenly between the supporting structure and the platform. The surface of the LSN tread must coincide with the front surface of the lower platform.

1. LS – main stage; 2. LSP – platform liner; 3. LSN – lower frieze stage

• LSV – upper frieze step. Designed to be installed as the last one on top. The surface of its tread must coincide with the front surface of the upper platform.

Upper frieze stage (LSV)

• LSS is a flat step for constructing flights without risers, the so-called through flights. It has a thickening in the center for attachment to the central stringer.

Flat steps (LSS)
The appearance of the finished staircase tells us about the similarity of the shapes of all steps. In fact, each type of reinforced concrete step shape has its own function and shape. Production of reinforced concrete steps LS, LSV, LSN https://www.youtube.com/watch?v=8ZSwVrNx-7M

Standard Requirements

GOST 8717.0-84 provides for the production of drugs without the use of reinforcing mesh to increase the strength of the product, if its length does not exceed 1500 mm. Concrete grade B15 is allowed for internal stairs, and not lower than B25 for external stairs. A standard step must withstand a load of 600 kgf/cm2. When calculating the load, its own weight is not considered. The main load is evenly redistributed to the stringers. Flights of stairs cannot be without guardrails. During the process of pouring reinforced concrete step forms, they must be equipped with steel inserts or sockets. These places will be used to attach fences. Depending on the left- or right-hand location of the mortgages, reinforced concrete steps are considered “left” and “right”.

Mortgages for stair railings

The lightest reinforced concrete step LSN 9.14-S weighs 41 kg, and the heaviest step LS 23-1 weighs 243 kg. Their transportation, unloading and installation requires special equipment. In order to facilitate work, GOST 8717.1-84 provides for the presence of loops that are located on the bottom or wrong side of the step. If you tie them with slings, you can damage the front surface and the step can be rejected.

To avoid damage to the steps during transportation, you need to use hinges

List of standards

Let's start with regulatory documents.

Useful: GOST 9818-85 contains a technical description of not only flights and stairs, but also separately produced concrete treads for them.

Standard requirements for the front surface

Reinforced concrete steps are resistant to abrasion of the tread surface. In accordance with GOST requirements, products made of lightweight concrete must be covered with a layer of heavy concrete with a thickness of at least 15 mm. The surface layer can also be made of synthetic concrete fillers. The main task of the front surface layer is to serve for decades. Therefore, the most stringent requirements are placed on finishing. In appearance, the front surface can be smooth, decorative or mosaic. A simple smooth surface is obtained using conventional cement grades.

Sanded reinforced concrete steps

The use of white cement or marble chips is considered a decorative design for the top layer.

Concrete steps lined with marble chips

Sanding reinforced concrete steps made of white or colored cement emphasizes the mosaic structure of the product. The same effect is obtained when grinding steps with marble chips.

Reinforced concrete steps made of white cement

or colored, they look quite original and unusual

Staircases made of reinforced concrete steps have, according to GOST, a riser surface inclined inward. The vertical difference between the rounded edge of the tread and the junction of the riser with the lower tread is 30 mm. This ensures convenience and comfort when moving. Steps made of concrete or reinforced concrete type LS and LSS have a tread depth of 330 mm. They are the main ones in the formation of a flight of stairs. LSN type steps have a depth of 290 mm. The type of steps LSV and LSP are limited by the depth of the tread or the width of the reinforced concrete product of 260 mm.

Tread depth

GOST 8717.0-84 Reinforced concrete and concrete steps. Specifications

STATE STANDARD OF THE USSR UNION

REINFORCED CONCRETE AND CONCRETE STEPS

GOST 8717.0-84

USSR STATE COMMITTEE FOR CONSTRUCTION

Moscow

STATE STANDARD OF THE USSR UNION

By Decree of the USSR State Committee for Construction Affairs dated April 23, 1984 No. 58, the introduction date was established

from 01.01.86

Failure to comply with the standard is punishable by law

This standard applies to reinforced concrete and concrete steps made from heavy concrete, lightweight concrete and dense silicate concrete and intended for the installation of internal and external stairs of buildings and structures.

Concrete steps are designed for constructing stairs on a solid base.

The steps are used:

for heated buildings and structures;

for unheated buildings and structures and outdoors at the design temperature of the outside air (the average air temperature of the coldest five-day period in the construction area according to SNiP 2.01.01-82) up to minus 40 °C inclusive;

with a non-aggressive degree of environmental influence on reinforced concrete structures.

It is allowed to use steps in buildings and structures with a design seismicity of up to 9 points inclusive, in unheated buildings and structures and in the open air at a design outdoor temperature below minus 40 ° C, as well as under conditions of exposure to an aggressive environment, subject to additional requirements established by the design documentation in accordance with the requirements of SNiP II-7-81, SNiP 2.03.01-84, SNiP 2.03.11-85 and SN 165-76 and specified in the order for the manufacture of steps.

The technical level indicators established by this standard are provided for the levels of the highest and first quality categories.

(Changed edition, Amendment No. 1).

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:

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

2. 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).

3. 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. 1 should be modified accordingly.

4 . 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.

5 . It is allowed to manufacture steps with dimensions different from those indicated in the table. 1, 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, steps type LS 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

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.

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.

4.1. Load testing of steps to determine their strength and crack resistance should be carried out when the concrete reaches a strength corresponding to the class of concrete in terms of compressive strength.

The strength and crack resistance of steps should be controlled according to GOST 8829-85.

4.1.1. Schemes for supporting and loading steps when testing them by loading are given:

types LS, LSV, LSP and LSN - to hell. 3;

standard sizes LSS12 and LSS15 - on the devil. 4;

standard size LSS24 - damn. 5.

The main parameters of support and loading of steps and the values ​​of control loads when checking strength and crack resistance are given in Table. 3 and 4.

4.2. The compressive strength of concrete should be determined according to GOST 10180-78 on a series of samples made from a concrete mixture of the working composition.

It is allowed to determine the actual tempering strength of concrete using the ultrasonic method in accordance with GOST 17624-78 or other methods provided for by the standards for concrete testing methods.

4.3. Frost resistance of concrete should be determined according to GOST 10060-87.

4.4. The water resistance of concrete should be determined on a series of samples made from a concrete mixture of the working composition, in accordance with GOST 12730.0-78 and GOST 12730.5-84.

4.5. The average density of concrete should be determined according to GOST 12730.0-78 and GOST 12730.1-78 on a series of samples made from a concrete mixture of the working composition.

4.6. The abrasion of concrete steps should be determined according to GOST 13087-81.

1

- movable support;
2
- fixed support;
3
– stage

Notes:

1 . Install the supports indicated on the support and loading diagram under the “bed” of the steps.

2. Support the “tail” of the platform liner and the steps of the upper and lower frieze over the entire surface.

Crap. 3

Crap. 4

Crap. 5

4.7. Methods of control and testing of welded reinforcement and embedded products - according to GOST 10922-75 and GOST 23858-79.

4.8. The dimensions of the steps, the deviation from the straightness of their front surfaces, the position of the reinforcement and embedded products, the thickness of the protective layer of concrete before the reinforcement, as well as the quality of concrete surfaces, the width of the opening of shrinkage cracks and the appearance of the steps should be checked by the methods established by GOST 13015 -75.

Table 3

Table 4

Notes to the table 3 and 4:

1 . The control load values ​​are indicated without taking into account the weight of the step.

2. C value

accepted depending on the possible nature of destruction of the stage in accordance with GOST 8829-85.

3. The load value when the first crack appears, at which steps of types LS, LSV, LSP and LSN are considered suitable, must be greater than or equal to the control one minus the weight of the step.

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.

Information

Interfloor and floor areas

Upper platform

1

— lower frieze stage (LSN);
2
— upper frieze stage (LSV);
3
— main stage (LS);
4
— platform liner (LSP)

CONTENT

Types of concrete for reinforced concrete steps

Concrete itself is a very versatile building material. Various fillers and binders are used for its production. These two ingredients determine the type of concrete. For the production of steps, the current standard provides for the use of three types of concrete. All three types meet the requirements for moisture impermeability, strength, loads, and thermal insulation properties.

Lightweight concrete

The first type is lightweight concrete. It got its name thanks to its light and porous fillers. This is porous limestone of volcanic origin, dolomite, crushed pumice stone, limestone shell rock, porous slag metallurgy waste and other fillers. Based on filler material, lightweight concrete is divided into types. But in this case we are not interested in the types of lightweight concrete, but in their properties.

Due to its porosity, lightweight concrete is almost half lighter than other types of concrete

First of all, this is its high level of porosity, reaching forty percent. The average density of lightweight concrete reaches 1800 kg/m3. With such indicators, concrete and reinforced concrete products comply with the requirements of GOST 8717. 0–84. Steps made from such concrete have good thermal conductivity and frost resistance up to F100. Products made from this type of concrete have much less weight, which reduces the cost of their transportation and installation.

Heavy concrete

The second type is heavy concrete. Fillers - crushed stone, granite and marble chips increase the density of such concrete to 2500 kg/m 3. Filler fractions up to 70 mm in size affect the ability of the product to deform during shrinkage over several years. But this in no way affects the strength properties of reinforced concrete products. Frost resistance, water resistance and thermal conductivity of heavy concrete meet the requirements of standard 8717. 0–84 for the production of reinforced concrete steps.

Heavy concrete is the strongest of the common types of concrete

Silicate concrete grades

This is the third type of concrete allowed for the production of steps. The composition of silicate concrete includes: sand, crushed and burnt lime, gypsum, water and binders. Its qualities are accepted by GOST for the production of steps and staircases. Its degree of water resistance is from B2 to B10, and its average density is up to 2400 kg/m3. Metal reinforcement and reinforcing mesh are located inside a homogeneous, high-strength artificial stone. It is formed as a result of hardening of the mixture and firing in an autoclave at temperatures up to 200°C.

Silicate concrete blocks

All three types of concrete fit perfectly within the framework of the applicable GOST. The production of steps from each type of concrete has its own characteristics. They are mainly manifested in the standard requirements for working surfaces.

Labeling secrets

In the GOST text you can find digital and alphabetic coding of reinforced concrete steps. The first group of markings is the letter designation of the shape of the step. The second marking from 9 to 23 indicates the width of the reinforced concrete product. Moreover, the width value is rounded up to a whole number. For example, a width of 1050 mm is indicated by the number “11”, and the marking “23” indicates a step width of 2250 mm. As we have already said, the height of reinforced concrete steps according to GOST can be 145 mm and 168 mm. The height of the LSS is always 100 mm, and we do not take it into account. If the product has a height of 145 mm, then this parameter is not displayed in the marking. But if there is a dot after the width of the product and parameter 17 is indicated, this means that the height of the step is 168 mm.

1. Step width; 2. Step height

The second group of letter codes is hyphenated and indicates the type of concrete:

• B – concrete, not reinforced concrete;
• L – lightweight concrete;
• C – silicate concrete;

Heavy concrete mixtures do not have a letter designation.

Encoded Properties

The third group of letter codes is also hyphenated. This group codes the option for processing the front surface:

• The letter “L” is placed only if the reinforced concrete step is located to the left of the embeds for fences. The mirror version of the product does not have additional markings.
• The smooth surface of the product using white or colored cement is marked with the letter “G”.
• The letter “Ш” denotes only the polished mosaic front surface.
• The letters “M” (frost-resistant) and “P” (high density) are placed if reinforced concrete products are made to special order for use in areas with winter temperatures below -40°C and for use in aggressive environments.

For clarity, let's give an example:

• LS9.17–LB – main step 900 mm wide and 168 mm high, tread depth 330 mm, left-hand version of concrete steps without reinforcement mesh.

Example of step markings

• LSP11–S–Sh – platform liner 1050 mm wide, 145 mm high, made of silicate concrete, polished mosaic surface.

The requirements of GOST 8717.0-84 correspond to safety and comfort standards. Knowing the specifics of marking and laying steps made of concrete or reinforced concrete, you will be able to independently control the installation of a staircase made from prefabricated steps in your home.

Contents of the standards

What do the documents we mentioned say?

GOST 8717.0.-84

We have already mentioned the area of ​​application of reinforced concrete steps - inside and outside buildings. GOST gives a more detailed definition: it is permissible to use them outside heated buildings in climatic zones with the coldest five-day period of the season, with an average temperature of -40 degrees. Contact of concrete with aggressive media is allowed, which allows the products to be used in production (including in the chemical industry).

The steps are divided into the following categories:

• LS is the main one.
• LSV - upper frieze (adjacent to the site).
• LSP - platform liner.
• LSN - lower frieze.
• LSS - flat for through marches.

LS type feet.

The main material for the products is reinforced concrete; however, the main steps of the LS up to 1.5 meters long can be produced without reinforcement.

The maximum short-term load for reinforced concrete products is 6 kPa, or 600 kgf/cm2.

A caveat: the calculated load does not take into account the own weight of the step. However, on a solid base it should be completely transferred to this very base, without loading the step.

The standard stipulates that reinforced concrete stair steps are produced with steel embedded parts for fastening railings. By agreement with the customer, however, mortgages can be replaced with sockets.

Flat steps LSS, in addition, are equipped with mortgages for fastening to stringers (supporting beams of the march) with a width of 155-180 mm; Additional embedded elements can be installed for a specific project.

If necessary, products are made left and right - depending on the direction in which the stairs rise. As a rule, this parameter only affects the location of the embeds or sockets for mounting the fence.

Depending on the project and in agreement with the customer, steps can be supplied with or without mounting loops. In the second case, the use of loading equipment with special grips is implied: the concrete products themselves cannot be rigged.

Massive reinforced concrete products are usually produced with mounting loops.

Steps made of lightweight concrete must have at least a 15 mm layer of heavy concrete or an abrasion-resistant coating of synthetic materials on the front surface.

The top surface finish may vary within the standard.

What options are possible?

1. Smooth concrete with regular cement.
2. Decorative concrete - on white, colored cement or marble crushed stone.
3. Mosaic concrete , obtained by grinding concrete on crushed marble and/or white and colored cement.

What are the dimensions of reinforced concrete stair steps?

• The width varies from 900 to 2380 millimeters.
• Height ranges from 100 to 168 mm.
• Tread depth - from 260 to 330 mm.

Several standard sizes of products.

Reinforced concrete steps weigh from 45 to 187 kilograms. If you are not an experienced strength athlete, obviously, you should not take on the task of moving and installing these products with your own hands, without loading equipment.

Design options for steps are described by a related regulatory document - GOST 8717.1-84.

Marking

It consists of alphanumeric groups and hyphens between them.

1. The first group indicates the type of step and its overall dimensions, rounded to whole numbers. However, the height of 145 mm is not displayed.
2. The second group contains the letters B - for concrete main steps, L - for products made of lightweight concrete and C - for silicate. Reinforced concrete prefabricated steps made of dense concrete, belonging to types other than LS, are not marked with the second alphanumeric group.
3. The third group contains:

• Numbers 1, 2, 3, etc., indicating the presence of mortgages or nests for fences. Number 1 corresponds to the design provided for by GOST 8717.1-84; other numbers refer to the design documentation.
• The letter L indicates the left design of the step (for stairs with a guardrail on the right side).
• The letter G means a smooth concrete surface on white or colored cement, the letter W means a polished mosaic surface. Smooth concrete based on ordinary cement is not indicated separately in the markings.

Concrete with marble crushed stone.

• M means increased frost resistance (can be used at -40C and below). P - increased density, allowing the use of products in constant contact with aggressive environments.

Marking samples

Let's give a couple of examples and look at them.

Technical requirements

GOST for prefabricated stairs and steps for them imposes certain requirements on the materials used and, of course, on the quality of the finished product.

• The compressive strength of concrete for external stairs should not be lower than grade B25. For internal stairs, the use of concrete grade B15 is allowed.
• The average density of lightweight and silicate concrete should not be lower than 1800 kg/m3.
• For products intended for use outdoors, in unheated rooms or at constant relative humidity above 60%, the fittings are protected from corrosion. The method is specified in the design documentation.

Useful: traditionally paints and varnishes are used for protection. However, it is now easy to find a more effective product on sale - a phosphating rust converter, which creates a durable film of chemically transformed iron oxides on the surface of corrosion-resistant steel. The price of the material starts from 200 rubles/kg.

Rust converter.

GOST 9818-85

The standard specifies the production of the following types of products:

The photo shows marches with half platforms.

The calculated loads without taking into account their own weight are:

• 360 kgf/cm2 for residential buildings.
• 480 kgf/cm2 for public buildings and industrial construction.

All elements can be produced in left and right versions.

The surface options are slightly different from those discussed above, within the framework of the previous standard:

1. Smooth concrete surface using regular cement.
2. Polished concrete surface on white cement, colored cement or marble crushed stone.

Let us clarify: this type of finishing is allowed only for landings and overhead treads.

1. In addition, the platforms can be finished with ceramic tiles, providing maximum wear resistance of the surface.

Marking

Here, too, it consists of several groups separated by hyphens (see also the article “Cinder concrete - everything you need to know about this type of material”).

The first group indicates the type of element and its dimensions. In general, the length and width are indicated in decimeters; for flights of stairs, their height (projection onto the vertical plane) is additionally indicated.

The markings indicate dimensions A, B and H.

Nuance: for a LMP march with one upper half-platform, the length is indicated equal to the length of a march with two half-platforms, belonging to the same type.

The letter B in the first group means that in front of us is the final platform or overhead tread for the upper final step.

The second group contains:

• For platforms and marches - the design load (number 4 corresponds to a load of 360 kgf/cm2, number 5 - 480 kgf/cm2).
• For overhead treads - left-hand design and type of surface finish (Ш - polished mosaic; the absence of letters indicates a smooth concrete surface).

The third group may include:

• The letter L, denoting the left execution of a march or platform.
• The letter K for the site means the presence of support consoles. The letter M is a technological hole for a garbage chute. The letter U is a reinforcement for supporting the march.
• In the case of the LMP march, number 1 indicates an elongated upper half-platform, 2 - an elongated lower half-platform, 3 - the absence of a lower half-platform.
• Ш - again a polished mosaic surface, K - facing with ceramic tiles.

Smooth concrete surfaces do not appear in the markings.

• The letter C indicates increased seismic resistance of the staircase structural element. Such products are used in the construction of buildings designed for 7-9 points on the Richter scale.

Marking samples

Technical requirements

They relate to the type of reinforcement used, surface abrasion, quality of concrete and maximum permissible deviations in linear dimensions.