Concrete blocks for the foundation
Laying the foundation is a crucial issue. Indeed, the strength of the building depends on the strength of the foundation. This is the basis of the building, it carries the greatest load. Provides stability, rigidity. To lay the foundation, it is necessary to use durable materials resistant to frost, moisture, and the destructive action of microorganisms. Concrete blocks for the foundation – just such a material.
- What are the blocks under the foundation
- Three types of foundation blocks
- Structural varieties of blocks for the construction of foundations
What are the blocks under the foundation
Foundation blocks – concrete products of medium and high strength, they are intended for the construction of strip and column foundations. This universal design can also be used for the construction of basement walls, basement and technical rooms, garages. Concrete blocks for the foundation must be resistant to temperature changes, strong, durable. For the manufacture of blocks most often used concrete is class M-150, M-100, M-200. Depending on the class of concrete, on the presence of a reinforcing cage, as well as on the production technology used, the foundation blocks of different degrees of resistance to mechanical stress and negative environmental effects are distinguished.
There are many characteristics by which concrete blocks are distinguished: compressive strength, frost resistance, water resistance, water absorption.
The choice of the best option depends on climatic conditions, on shrinkage, on moisture and soil density. One of the main criteria for choosing a foundation block is the boundary load that will fall on the foundation.
Three types of foundation blocks
- FBS – solid foundation blocks;
- FBV – continuous fundamental blocks with a cutout for laying jumpers and conducting communications;
- FBP – hollow (“P-shaped”) foundation blocks.
Solid foundation blocks are the most common, made of heavy concrete or high-density silicate concrete. They are the main element of strip and column foundations. Such a block is strong enough and has a high density, which is why FBS blocks are used as a basis in supporting structures; such blocks are used in the construction of skyscrapers and for the construction of private low-rise buildings. In addition to being used as a foundation, it is possible to use for the construction of walls in the basement of buildings.
Hollow concrete blocks are used as fixed formwork. During the construction process, the voids in the blocks are filled with concrete. The blocks are designed so that the horizontal joints are reinforced. Before filling, reinforcing rods are inserted into the voids, which provides additional structural strength. The fundamental walls erected from hollow blocks, with the filling of voids with concrete, have increased compressive strength, and reinforced with vertical reinforcement also have increased strength under lateral loads.
Hollow blocks are of various sizes, the most common are 51:40:25, 51:20:25 and 51:25:25.
To facilitate communication, use the fundamental blocks with special technological cutouts for communications. Classical (heavy) concrete blocks are used or lightweight – expanded clay concrete.
Concrete blocks under the foundation are made of expanded clay concrete, reinforced concrete, and also high-density silicate concrete.
Expanded clay blocks have good thermal insulation properties, but also high water absorption – a thorough waterproofing of the foundation is extremely important. The foundation of expanded clay concrete blocks can be built only in the absence of high-level groundwater. Expanded clay blocks are lighter and cheaper. They are ideal for garage foundation or a bath.
It is advisable to build a house with heavy walls (brick, stone, from cinder block) on a strip foundation of FBS blocks. The foundation of concrete blocks of columnar type is ideal for a wooden building.
Concrete blocks are used for laying the foundations of buildings of any purpose and all types.
Structural varieties of blocks for the construction of foundations
- F – reinforced concrete (reinforced), as well as concrete from heavy concrete;
- FBS – solid, unreinforced;
- FL – reinforced concrete (reinforced), used for strip foundations;
- BF – reinforced concrete, from heavy concrete;
- FBP – hollow;
- FR – reinforced concrete, from heavy concrete, for three-hinged frames.
The dimensions, shape and weight of concrete blocks are different. For high-rise buildings, large blocks are needed, for low-rise buildings, much smaller.
Wall blocks in cross section form a quadrangle, some blocks are made with additional cutouts. Such blocks are used for the underground and aboveground parts of the foundation. Pillow blocks – trapezoidal shape (to increase the supporting area), are used for laying the first row of the foundation.
Reinforced concrete blocks for the foundation are factory-made products, which means guaranteed quality and identity of the characteristics of all reinforced concrete blocks of the same brand. The use of foundation blocks can significantly reduce the volume of concrete and cement works, which means significantly reduce construction costs.