Utilizing high volumes quarry wastes in the production of lightweight foamed concrete

Quarry dust, a by-product of stone grinding, cutting, sieving and crushing, is abundantly available and can create many on-site and off-site environmental problems. This paper investigates the feasible utilization of quarry dust as an alternative to river sand in the production of lightweight foamed concrete (LFC). LFC with a density of 1300 ± 50 kg/m3 and fixed cement/filler ratio of 1:1 were adopted in this study. Quarry dust was used to replace sand at ratios of 75% and 100%, and four different water-to-cement ratios (w/c) of 0.52, 0.54, 0.56 and 0.58 were studied and compared. For a given w/c ratio, it was found that the use of high volume quarry dust could reduce the fluidity and increase the compressive strength and the thermal conductivity of LFC. However, no significant decrease of compressive strength was observed with the increase of w/c ratio, probably due to the reduction of foam volume requirement in the system. Life cycle assessment results indicated that the LFC containing quarry dust possessed less environmental impact in terms of lower energy consumption and lesser amount of greenhouse gases emission.