What Is Lightweight Concrete?

Lightweight concrete, also known as foam concrete, is used to foam the foaming agent mechanically through the foaming system of the foaming machine, mix the foam and the cement slurry uniformly, and then perform the cast-in-place construction through the pumping system of the foaming machine. Or mold molding, a new type of lightweight thermal insulation material containing a large number of closed pores formed by natural conservation. It is a bubble-like thermal insulation material, and the outstanding feature is the formation of closed foam cells inside the concrete, which makes the concrete lightweight and heat-insulating. At the same time, it is also a special species in aerated concrete. For aerated concrete, the difference between the two is only the difference between the shape of the pores and the means of aeration.

Lightweight concrete

Aerated concrete pores are generally oval, and foamed concrete is affected by capillary pores and deforms to form polyhedrons. Aerated concrete uses chemical gassing to generate pores from internal gas through chemical reactions. Lightweight concrete It is made by mechanical foaming method. The foaming agent is first made into foam, and then the foam is added to cement, magnesite, gypsum slurry to form a foam slurry, and then cured by natural curing steam.

Lightweight concrete is a member of the large concrete family. In recent years, domestic and foreign countries have attached great importance to the research and development of foamed concrete, which has made it more and more widely used in the construction field. The relevant situation is now introduced as follows:

Lightweight concrete is usually made into foam by mechanical methods. The foam is then added to a slurry consisting of siliceous materials, calcareous materials, water and various admixtures. After mixing and stirring, casting, A porous material that is cured. Because foam concrete contains a large number of closed pores, it has the following good physical and mechanical properties.

1.Lightweight

The density of lightweight concrete is small, the density grade is generally 300-1800kg / m3, the density grade of commonly used foam concrete is 300-1200 kg / m3, and in recent years, ultra-light foam concrete with a density of 160 kg / m3 is also in construction Got the application. Due to the small density of lightweight concrete, the use of such materials in the building's internal and external walls, floors, floors, columns and other building structures can generally reduce the building's own weight by about 25%, and some can reach the total weight of the structure 30% -40%. Moreover, for structural members, if foam concrete is used instead

Lightweight concrete is widely used in energy-saving wall materials due to its good characteristics, and has also been used in other aspects. Currently, light coagulation

1.The test block floats in the water without melting or sinking.

This shows that the lightweight concrete (foam concrete) has been completely hardened and the air holes are completely closed. The closed-type foam concrete air does not generate convection in the body, reduces the conduction, radiation, and diffusion of temperature, and the heat energy gradually weakens in the pores, achieving the effect of thermal insulation. And the water absorption rate is low at about 5%, and the physical properties of sound insulation, waterproof, compression resistance and flex resistance are the best.

2.If the test block sinks slowly

The water absorption rate is 30%, which exceeds the specific gravity of water. This means that the light concrete (foam concrete) pores are semi-open, and some of the pores are connected from the surface to the inside. The air will generate convection in the body. As the opening of the stomata increases, the absorption and storage rate will increase to about 50% with the stomata connection rate, and the physical properties of heat insulation, heat preservation, sound insulation, waterproof, compression resistance, and flex resistance will be greatly reduced.

3.The test block quickly sinks into the water

The water absorption rate exceeds 30% and exceeds the specific gravity of water, indicating that the pores in the material are fully open, forming a channel from the surface to the inside. The air generates convection in the channel, and the air conducts the temperature of the material in the convection through water , Radiation, diffusion, water absorption and storage rate will increase to more than 50% with the stomatal connectivity rate, the material loses the performance requirements of thermal insulation.