Abstracto

Effect of nano-silica on the properties and form mechanism of foamed concrete

Zhang Jing, Liu Xiangdong

Foamed concrete is usually made of cement and fly ash, with H2O2 and Fecl3 as foaming agent, and calcium stearate as foam stabilizer. Nano SiO2, or nano-silica, can be used as an additive to change the properties of concrete. In this paper, the effect of nano-SiO2 on the compressive strength of foamed concrete is investigated, as well as the additive mechanism is analyzed. Experimental results show that compressive strength at 7-th days can be improved up to 15%, and at 28-th days can be improved up to 18%, respectively through adding nano SiO2. The improvement is explained as that nano-SiO2 changes the microstructure and the interactions on the surface of foam to shorten the foaming time