It is difficult to imagine a modern urban landscape without many multi-storey buildings, which, in turn, can not do without flights of stairs, so necessary for industrial and residential buildings.
In mass construction, the most widespread are reinforced concrete staircases. Despite their unsightly appearance, they have many useful characteristics.
Advantages
Such products are distinguished by the absence of cost in use, ease of decoration, low cost and high strength. Their mass production is carried out in accordance with GOST, which regulates dimensions and properties. They also have a long period of use, low susceptibility to wear and fire-resistant characteristics achieved through the use of material not subject to fire.
Prefabricated reinforced concrete flight of stairs is made of heavy-duty waterproof concrete with high frost resistance, reinforced with special metal rods and reinforcing wire.
Thanks to the basis of high-quality raw materials, these building structures can be used in regions with seismic hazard and changing climatic conditions to create panel-frame buildings for industrial, residential and public purposes, not only inside houses, but also from the outside. It is possible to use as basement, basement and interfloor structures.
Types
In large buildings, the staircase is divided into marches, the number of which depends on the number of floors. Marches are steps that are mounted on load-bearing beams. The device of the flight of stairs is to connect the staircases with two marches.
There are two types of such stairs - prefabricated and monolithic. The latter are a classic design in the form of reinforced concrete solid block, which has gained the greatest distribution in typical houses.
Prefabricated reinforced concrete products are based on kosoura or bowstrings, they are more convenient when creating elements with non-standard dimensions. Reinforced concrete staircases with platforms are divided according to structural design into rotary, circular, multi- and single-march. There are also modifications for moving left or right.
Ribbed concrete goods with frieze steps are installed on beams with reinforced reinforcement; there is a frieze for attaching to platforms. Flat versions are marked LM and are based on a reinforced flat plate. The designation LMP is used for flights of a ribbed appearance with an integrated platform. Despite the possibility of use only subject to preliminary calculations or in typical houses, they are convenient and reduce the construction period.
Stair march: dimensions
Reinforced concrete structures, the main dimensions of which are represented by the width, projection height and length, are available in standard size. Due to this, it is possible not to make preliminary calculations when using monolithic options. In prefabricated bases, beams and steps are made in standard dimensions with differences for stairs of any purpose. The march can have a length of up to 6900 mm with a set width of 650 to 1700 mm. The minimum step height is 150 mm.
Change settings
Due to the existence of many models of reinforced concrete products, it is easy to install finished structural elements in houses with rooms not exceeding a certain height. But sometimes there are some inconsistencies.
If the reinforced concrete staircases are too high, the excess is eliminated with the help of the frieze bottom element, drowning in the base. At the same time, an increase in the mounting height for the lower stage is not allowed, as this can lead to injury, most often occurring in low light.
To solve the problem, a change in the level of the lower element by several degrees is used. The tilt compensates for the excess height and will not be noticeable during movement. The shape of the upper plate changes with a lack of length of the march, while the protrusion of the upper element becomes the protrusion of the lower edge of the plate.
Ready-made designs
With a lack of free space, which often occurs during individual low-rise construction, precast concrete products are made to order, in accordance with the initial parameters. The height of the step in this case is the main guideline size.
Ready flights of stairs (reinforced concrete) gained their wide distribution due to quality characteristics and versatility of use. They reduce construction costs and speed up its implementation. The unsightly appearance can be completely transformed by decorative finishes, the options for which depend on financial capabilities and the overall style. Actively used painting, decoration with artificial stone, tile or tile.
Reinforcement
Strengthening marches is necessary in places where there is no high-quality support under the middle part of the structure. Due to the reinforcement cage, breaks and cracks in concrete are prevented, thus reinforced concrete staircases become more durable.
Steel rods are laid along the supporting base with subsequent connection with high-quality transverse bonds. A metal corner is used to close the edge of the steps to avoid crumbling. Reliable bonding of concrete and corner is ensured by welding of steel wire elements.
Before pouring the concrete mass into the formwork, mortgage plates made of metal or wood corks are mounted; subsequently, a railing is fixed to them.
Given that the concrete mass should not have layers, each degree is poured in one step. The planes of the created marches, steps and platforms upon completion of pouring the mortar are leveled with special tools. After the final solidification of the mass, reinforced concrete staircases are ready for use.