Residual strength capacity of reinforced reactive powder concrete twoway slabs subjected to drop weight

Abstract

This paper presents an experimental investigation of the effect of impact force on the residual strength capacity of simply supported reactive powder slabs. Eight specimens of reinforced reactive powder concrete slabs were examined in the research. These slabs had dimensions of 500 x 500 mm and 70 mm in four categories. The influence of slab compressive strength (conventional concrete and reactive powder concrete), steel fiber proportion (1, 1.5, and 2%), percentage of reinforcement in the tension zone (ρ1=0.007, ρ2=0.011, ρ3=0.0179), and the number of impacts (two impacts, four impacts, and six impacts) were investigated in this research. Investigations were carried out to ascertain each slab's residual response, including the first cracking load, residual failure load, residual steel reinforcement strain, maximum central deflection, and crack pattern. The results showed that using reactive powder concrete instead of normal concrete increased the mechanical properties of the concrete and resulted in a significant increase in the failure load. This also led to an increase in deflection and strain. Furthermore, increasing the reinforcement ratio increased the failure load while simultaneously decreasing the deflection due to the improvement in slab moment resistance. Furthermore, it was discovered through the experiments that the addition of steel fiber to the mixture enhanced the slab’s post-cracking reactivity. The presence of steel fiber raised the slab's strength resistance by 21.63% as the steel fiber ratio increased from 1% to 2%, which is due to the addition of steel fiber increasing the slab's tension resistance.