Preparation and Properties of Foamed Concrete with Iron Tailings Sand

Iron tailings sand was used as fine aggregate, and different dosages of iron tailings sand were used to replace natural sand to prepare foam concrete specimens with a target density of 900 kg/m³, and the effects of iron tailings sand dosage on the specimens’ properties such as drying shrinkage, water absorption, thermal conductivity, compressive strength and splitting tensile strength were analyzed; and scanning electron microscope and graphic analyzing software were also used to analyze the microscopic morphology of the specimens. The results show that the iron tailings sand mixing (mass fraction) in the range of 0–40%, with the increase of iron tailings sand mixing, the drying shrinkage and water absorption of foam concrete decreases, the thermal conductivity increases slightly. The foam concrete compressive strength and splitting tensile strength show a trend of increasing first and then decreasing, and the highest compressive and splitting tensile strength is observed when iron tail sand mixing is 20%. The pore structure of foam concrete can be improved by adding appropriate amount of iron tailings sand, and the internal pore size tends to be uniform, and the microstructure of foam concrete deteriorates when the mass fraction of iron tailings sand is more than 20%, which is also the reason why its mechanical properties begin to decline.