Abstract: Alkali activated slag cement was used to prepare a foamed concrete, with compressed air foaming process.The pore structures of the foamed concretes were investigated by image process software(Image-Pro plus, IPP).The effects of foam content on the dry density, compressive strength and thermal conductivity of foamed slag-based geopolymers were studied.The results show that porosity, average pore diameter and roundness increase, when foam content increase from 4.45%-10.70%.A good negative exponent relationship between foam content and the main properties of the foamed slag-based geopolymers was observed.The dry density, compressive strength and thermal conductivity were in the range of 389-1325 kg/m3, 1.12-17.81 MPa, 0.0813-0.2211 W/(m·K), respectively, when foam content increased from 4.45%-12.00%.In comparison to Portland cement foam concrete,foamed slag-based geopolymers presented a lower thermal conductivity and a higher compressive strength.

Key words: slag-based geopolymer;foam content;pore structure;compressive strength;thermal conductivity