Flexural behavior of slabs made of lightweight foamed concrete with basalt powder

Purpose Cement can be replaced to reduce the energy consumption and the environmental impact of cement. Also, foamed concrete can be used structurally in residential buildings to reduce weight and improve thermal insulation. To achieve these two goals, this paper aims to investigate the effect of basalt powder as a partial replacement of either cement or sand. Design/methodology/approach This paper investigates the effect of basalt powder as a partial replacement of either cement or sand on the mechanical properties of foamed concrete used to cast slabs. First, mechanical properties of foamed concrete are tested with and without replacement of basalt. Then, six slabs of different thicknesses and mixes are investigated. The thicknesses considered are 150- and 200-mm slabs. The three mixes used to construct these slabs are foamed concrete with no basalt powder, foamed concrete with replacement of 20% of cement by basalt powder and foamed concrete with replacement of 20% of sand by basalt powder. The flexural behavior of these slabs is investigated. Findings All the slabs failed in the commonly intended flexural mode. The results show that the basalt powder acted as a strong filler material in the foamed concrete mix based on mechanical properties and flexural behavior. The proposed foamed concrete slabs can be used structurally in residential buildings. Originality/value A natural waste material that can be used to promote energy efficiency and reduce emission is basalt. In this paper, basalt powder is suggested to be used due to its chemical composition that is similar to cement. Also, basalt powder is low in cost as it is waste, while basalt aggregate is prepared, and it is only used as filler in paved roads. Accordingly, basalt is partially used instead of cement to reduce the emission of carbon dioxide that results from the cement manufacturing. Also, it is used as a partial alternative to sand which can be considered as a new stronger source as filling material used in the production of concrete.