What are the raw materials of foam concrete? Let's take a look together.
1. Cementing material
The cementing material, which is one of the most important raw materials for foam concrete, plays a role of bonding. According to the use of cementing materials, calcium silicate materials, magnesite materials and gypsum materials can be selected. Silicate cement is the most commonly used cementitious material for foam concrete. The setting strength and setting time of various grades of cement are different. Even if the composition of the same grade of cement is also different, because it is produced by different manufacturers. Therefore, for the same cementing material, large-scale construction only can be carried out on the basis of small-scale test in principle.
2. Foaming agent
Foaming agent is the general name of foaming agent, foam stabilizing agent and binding agent (composite foaming agent includes the above-mentioned additives). Foaming agent is a kind of material which can produce gas by chemical reaction. Foam stabilizer is a kind of surfactant, such as sodium dodecyl benzene sulfonate, hydrolyzed protein. Water binding agent and other additives refer to those substances that can interact with the hydrophilic end of surfactant through hydrogen bond, and strongly adsorb water molecules and bubble surface, such as polyacrylamide, Alain gum.
According to the use and resources, fly ash, slag powder, sand, stone powder, ceramsite, pumice and expanded perlite can be selected (or not added) as aggregate. Among them, fly ash and slag powder belong to waste recycling, which is in line with the national industrial energy saving policy and has the most application and development value.
The additives, such as water-reducing additive, stabilizer, coagulant, early strength agent and waterproofing agent, can be added according to the usage and construction conditions of foam concrete.
Generally, the proportion of water is 60% of cement. The amount of cement depends on the volume of foam concrete. The pure cement foam concrete is more commonly used and the bulk density comes mainly from cement. However, there are many places have begun to add some light aggregate and other auxiliary materials to improve cement performance.