Standard dimensions of slabs

The structures for the device of overlap between the floors of the building under construction are reinforced concrete products. They are made with admixtures of concrete from a number of heavy grades, light type of structural concrete with a dense structure, and also of reinforced silicate concrete. The main application of the slab plate is the erection of the bearing part of the horizontal planes of large-panel buildings. The effective load on the products should not exceed the prescribed 6 kPa, while the weight of the structure is not taken into account. Laying of hollow core slabs should be made on the base (wall) for a distance of at least 150-200 mm, with the obligatory condition that the support will be stronger than the product itself.

Among the main types of structures for the formation of overlap are the following:

• PPP - threaded reinforced concrete slabs;
• Ribbed or with a trough profile;
• Hollow (hollow-core);
• Monolithic.

Marking of hollow plates means the following:

• 1П - concrete single-layer structures with a height of 120 mm;
• 2P - the same plate, but of a greater thickness (160 mm);
• 1PK - hollow-core (220 mm), inside which there are round voids with a diameter of 159 mm;
• 2PK - the same plate, the diameter of the cavities - 140 mm;
• PB - hollow with a height of 220 mm, the method of formation - without the use of formwork.

Plates overlapping hollow, the sizes which are within the limits of standard, remain one of the most convenient building details. They are not ignited, do not rot, are extremely durable and reliable, and are resistant to moisture.

The dimensions of the overlapping plates consist of parallelepiped parameters, inside of which there are voids in the form of cylindrical pipes. The presence of these containers gives the structure the rigidity property of bending, which makes it possible to withstand significant loads. Moreover, the emptiness greatly facilitates the process of laying in them all possible communications during the erection of the building.

The standard overall dimensions of slabs is a firm guarantee of an adequate cost of reinforced concrete products. However, designs with dimensions outside of the usual can be created by individual drawings. Although it is better for an economical builder to use the standard sizes because of the higher cost of manufacturing non-standard slabs as a result of additional costs.

Typical sizes of floor slabs with voids are along the length in the range from 2.4 to 6.6 m, which depends on the catalog with the series for a typical product. The usual width can be 0,6 - 2,4 m at intervals with different steps. The height (thickness) of the plates is adopted at the level of 220 mm, and the total weight of the whole product is up to 2.5 tons.

The dimensions of the hollow-core type overlapping plates are encrypted in the marking of each product, and they should be understood in this way, for example, PC 72.15-8:

• The PC means the following: a hollow core plate with round cavities with a diameter of 159 mm, a maximum height of 220 mm, both sides are intended to be supports;
• 72 - the length of the product in decimeters (that is, in millimeters - 7180);
• 15 - width in decimeters (or calculated 1500 mm);
• 8 - the load that the plate can withstand, in kPa.