Use of Foundry Green Sand Waste in Development of Foamed Concrete

Abstract

The main aim of this work was to evaluate the substitution of the natural sand by the foundry green sand waste in the production of foamed concrete. The experimental design consisted two factors with different levels: proportion of green foundry sand waste at five levels (0%, 25%, 50%, 75%, 100% in relation to total mass) and foam content at four levels (5%, 10%, 15%, 20%). The substitution of natural sand was made in relation to the mass of material. The influences of each factor on compressive strength, density (dry and saturated), air voids and water absorption were evaluated. From the results, it can be seen that all factors had a significant influence on the response variables, i. e., increasing the foam content, the compressive strength, the dry density and the saturated density decreased by an average of 32.9%, 21.0% and 14.5%, respectively. Already the air voids and water absorption increased, on average, by 44.1% and 76.9%, respectively, with the increase in the foam content. It was also observed that increasing the percentage of substitution of the waste in relation to the amount of natural sand, the dry density increased, on average, 23.7% and the saturated density increased, on average, 14.1%. Compressive strength, air void and water absorption decreased, 29.1%, 31.0% and 43.5%, respectively, with the increase in the percentage of substitution. According to the results, it is possible to verify that the foundry green sand waste has the potential to be used in the foamed concrete blocks manufacture, however studies evaluating the durability and environmental effects must be carried out, as well as in previous studies that use this waste, for example, in conventional concrete and mortars and also on pavement.