Lightweight Concrete Additives

Lightweight concrete additives can be used to replace dense natural aggregates in structural concrete. These additives can reduce the costs of materials and handling. They can also increase the thermal insulation of the concrete and improve its fire resistance.

Foamed concrete is one of the most commonly used lightweight concretes. It is produced through a pre-forming process. The foaming agent introduces randomly distributed air bubbles into the mixture. This results in lower density.

The main components of a foamed concrete are the foaming agent and stabilizer. The stabilizing agent is usually added in the slurry of the foamed concrete batch.

Aside from reducing the cost of the material, these additives can improve the structure and the performance of the lightweight concrete. Using these additives can help in reducing the steel requirements for the project.

Several studies have been conducted to investigate the compressive strength of various types of lightweight concrete. It has been observed that the densities of concrete in the range of 350 to 50 kg/m3 are acceptable.

However, the densities were slightly lower than those in the case of normal weight concrete. Some of the studies investigated the influence of nanosilica on the densities of foamed concrete.

Another study investigated the influence of supplementary cementitious materials on the performance of ultra-lightweight foamed concrete. The authors found that the inclusion of these ingredients reduced the shrinkage rate of the concrete.

Furthermore, the use of nanosilica improved the strength of the concrete by refining the pore structure. In addition, the density of the concrete increased with the incorporation of nanosilica.