Foaming agent is a type of additive that increases the density, porosity, stability and fluidity of foam concrete. It is a water soluble protein hydrolysate that is added to the concrete slurry during mixing to form a foam. It can be produced from glue resins, detergents, resin soap, saponin or hydrolyzed proteins [2,3,57].
Effect of foaming agent on the properties of foam concrete: – Density and Thermal Conductivity
The density of foam concrete depends on the amount of foaming agent added into the samples. The increase in foaming agent content results in a larger sample volume. Moreover, the density of foam concrete is affected by the pore size of the coarse aggregate used.
– Water Absorption
The water-to-cement ratio (w/c) of the concrete slurry is an important factor in determining the pore structure and permeability of foam concrete. The larger the w/c ratio, the higher the pore diameter and the greater the number of pores. The pore diameter and distribution also contribute to the absorption of water in the concrete.
The workability of foam concrete is affected by the type of aggregate used, the fineness of the aggregate and the presence of superplasticizers. The use of inert dust as the fine aggregate reduces the workability because it has a smaller diameter than natural sand.
– Friction and Cracking
The hydration temperature of foam concrete also affects the cracking and fracture behavior. The lower the hydration temperature, the better the cracking and fracture behavior of foam concrete.