Potential use of soil in lightweight foamed concrete

This research investigates the application of soil in foamed concrete as a sand replacement. Foamed concrete with dry densities ranging between 800 and 1500 kg/m3 and cube strength from 5 to 25 MPa tested. The potential improvement of soil-based foamed concrete regarding thermal insulation compared with sand-based foamed concrete was also investigated. Silica fume was also used to improve the properties of soil-based foamed concrete. Dry density, 28-day compressive strength, and thermal conductivity and pore structure tests, were conducted to investigate the effects of silica fume on the properties of foamed concrete. Results show that the replacement of sand with soil can significantly decrease the dry density of foamed concrete. Also, the compressive strength and thermal insulation improved by the addition of silica fume. In the end, a soil-based foamed concrete with a density of 800 kg/m3, compressive strength of 7.5 MPa and thermal conductivity of 0.16 W/mK was produced.