Effects of foam and activator contents on the properties of alkali-activated slag foamed concrete and a prediction model

The influence of foam content and activator content on the properties of alkali-activated slag foamed concrete (AASFC) was studied. It was found that, when the foam content was increased from 3% to 12%, the effective foam ratio (EFR) and the water absorption of the AASFC increased, while the compressive strength and dry density decreased. For the same foam content, when the activator content was increased from 4% to 6%, the EFR and water absorption decreased, while the dry density increased. The AASFC showed good performance with an activator content of 5%. When the foam content was increased, the amount of large pores and interconnected pores increased. However, the foam content had little effect on the average pore size and pore roundness. For the same foam content, when the activator content was increased from 4% to 6%, the porosity and amount of interconnected pores decreased. With an increase in foam content from 9% to 12%, the porosity increased significantly and the thermal conductivity was significantly decreased. A property prediction model was established that may provide the foundation for AASFC mix design.