Advantages and Disadvantages of Foam Concrete

Foam concrete is a typical inorganic wall thermal insulation material. It is used in the construction of flat roofs, cold storage, retaining and abutment walls, as non-load bearing or load bearing walls in RCC/Steel framed buildings, infill to arch bridges, in tunnels, subways and wells.

Advantages of foam concrete include its light weight, good environmental protection performance, excellent thermal insulation properties, high scope for industrialisation, and convenient construction [6,7]. On the other hand, it has some disadvantages, including its poor strength and dry bulk density.

Lack of rigidity

A key component that affects the performance of foam concrete is the foaming agent and the foam stabiliser. These substances influence the air content, fluidity, and volume stability of the fresh slurry and eventually determine the dry bulk density and strength of the hardened body.

Excessive fly ash can cause the development of bubbles, which may lead to segregation. This can also reduce the complete volume and increase the risk of collapse of the foam structure.

The optimum porosity of foam concrete should be achieved by optimizing the interporous partitions and pore space in the volume. This is possible through the use of supplementary cementitious materials such as ground granulated blast furnace slag (GGBFS), fly ash, and silica fume.

In addition, the amount of fly ash used in the foaming process can have a significant effect on the final quality of the product. The dry bulk density of foam concrete with 0-20% fly ash decreases, and it increases when the blending ratio of fly ash is 10-40%.