Structural response of reinforced LECA aggregate concrete slabs subjected to high temperatures

Abstract

This work reports tests conducted on nine one-way reinforced concrete slabs using lightweight expanded clay aggregate (LECA) as a slab weight reduction technique. Every slab had the same dimensions, steel reinforcement, and the same composition of concrete. The slabs were heated from their bottom faces through a fire chamber and subjected to a sustained line load. The specimens’ fire resistance performance and mechanical characteristics were evaluated after they had undergone the same testing conditions. The study parameters were the replacement of coarse aggregate with different percentages of LECA (20%, 40%), and different temperatures (400 ℃ and 700 ℃). Compared to the reinforced normal-weight concrete slab, the reinforced LECA aggregate concrete slabs’ fire resistance and flexural strength decreased by LECA. The slabs’ deflection rose as the LECA increased. The largest increase in slab deflection was 37.2%, while the most notable decrease in ultimate load capacity was roughly 35.1%. The stiffness depreciation was substantial, though, at roughly 50%. The results for LECA-reinforced aggregate slabs not exposed to high temperatures support this conclusion. Reinforced LECA aggregate slabs maintained structural integrity after fire testing.