Instantaneous and long-term performance of foamed concrete slabs

Abstract

This research is part of project conducted to build energy-efficient houses. It is suggested to replace normal weight reinforced concrete slabs and the thermal insulation layer with structural foamed concrete slabs. As strength requirements were previously investigated, the long-term deflections of six foamed concrete slabs with various reinforcement schemes are studied in this paper. First, deflection under own weight was measured for 36 days. Then, a load of 3 kN/m2 was applied and the deflection was measured continuously over one year. Afterwards, part of the applied load was removed, and specimens were under own weight and 1.7 kN/m2 for another year and then tested for flexural capacity. It is concluded that foamed concrete slabs should not be reinforced with glass fiber grid due to their insufficient flexural strength although these slabs had the least deflections. Reinforcing foamed concrete slabs with steel is suitable for structural use. A modification on effective moment of inertia equation available in literature is proposed to predict deflection that can represent the experimental outcomes. It is also found that the deflection results of foamed concrete slabs satisfy the codes limitations. Moreover, it is concluded that more specimens should be tested under various geometric and reinforcement details.