Foam Concrete Blocks
During the execution of construction works usual bricks are more often replaced with foam concrete blocks. The material proved itself as light, strong; it has good heat insulation properties, comes cheap.
Classification of Foam Concrete Blocks
There is a classification by the material density, which main characteristics of items depend on, such as specific gravity, bearing load, heat conductivity, sound-insulation value.
Heat insulation (D150-D400). The frost resistance and strength of this type of foam concrete blocks are not defined. The strength is В0,75. The heat conductivity is low. As to the design, they are heat-insulating (D500, D600, D700, D800). They have in comparison with the previous type increased strength. The load is to 30 kg/cm3. Building blocks are D1000, D1100, and D1200 grades. Increased density is peculiar therefor. The strength grade is В12,5 (maximum). As to the design, they are aerated (grades from D1300 to D1600). There are no symbols in DSTU, they are manufactured in small lots.
Technological characteristics of manufacturing divide foam concrete blocks into the following groups:
- reinforced: during the manufacture polypropylene fiber is added for the increase of the item strength.
- formed: it is manufactured using forms, equipped with partitions.
- cut: using steel wire finished crude mixture is cut.
- Autoclaved slag blocks are dried under high temperatures. Non-autoclaved blocks are got hard in steam curing chambers or under the natural conditions.
Methods of Application
Foam concrete blocks are used at various stages of construction. Specifications of the material influence the peculiarities of its use.
Heat insulation blocks may be used for warmth-keeping of floor slabs, carrying walls, and roof void. They are used to fill up the cast-in-situ frame.
Heat insulation and building blocks because of their increased strength may be used for partitions, carrying walls of law constructions.
The structural type of foam concrete blocks is bought for the installation of carrying walls. It should be noted that you will need additional heat insulation.
Foam concrete blocks may be used for (stay-in-place) formwork pouring. It isn’t appropriate for the foundation since it has a cellular structure.
Portland cement (М400). Binding agent. Sand or expanded clay aggregate. Filler. Foaming agents. Concentrate prepared based on glue, gelatine, colophonium. Water. Requirements are as follows: cement ratio is 1:2:5, the temperature is 22 – 25 °С.
There are only two main manufacturing technologies:
- All components are mixed (in the mixer). The air is drawn into the resulting solution due to the rapid mixing. Pluses are as follows: method accessibility and Minuses lie in the fact that foam received because of the movable solution, a necessity to use chemical additives.
- The ready-made solution is added foam, obtained in the foam generator. The technology allows controlling the process at each stage, but it is required to use expensive equipment.
Qualitative raw materials, no errors in the content, and meeting the requirements of the manufacturing technology guarantee, that the resulting material will have the required excellent properties.