Development of fiber compound foaming agent and experimental study on application performance of foamed lightweight soil

In order to prepare high-performance foaming agent for field-cast foamed lightweight soil, the fiber compound foaming agent was prepared by the combination of anionic surfactant sodium dodecyl sulfate (SDS) and nonionic surfactant alkyl polyglucoside (APG), supplemented by hydrolyzed polyacryamide (HPAM) as the foam stabilizer. The effects of the mass ratio of surfactant and the content of foam stabilizer on the properties of fiber compound foaming agent were compared and analyzed by testing the surface tension, viscosity, foam volume, and foam half-life. Based on the analysis of foam volume and foam stability of foaming agent, the optimal mass ratio of surfactant and the optimal content of foam stabilizer were optimized. In addition, based on the optimized fiber compound foaming agent to prepare foamed lightweight soil, the influence of different foaming agent concentrations on the application performance of foamed lightweight soil was studied, and the appropriate concentration of fiber compound foaming agent solution was further optimized. Thus, the optimum reaction conditions for preparing SDS-APG compound foaming agent containing foam stabilizer HPAM were proposed as follows: mass ratio of SDS to APG was 2:1, concentration of HPAM was 3.75 wt‰, and concentration of foaming agent was 9.21 wt%.