Innovative approaches to deflection analysis in strengthened reinforced concrete Slabs: Combining experiments and theoretical research

Abstract

Structures often experience high-stress conditions, leading to premature deterioration and costly replacements before their intended design life ends. To address this issue, strengthening techniques are employed to mitigate the degradation of reinforced concrete (RC) slabs. This study focuses on investigating the flexural strengthening of RC slabs. Specifically, it examines the impact of different externally bonded plates and slab thickness on the deflection of RC slabs during the pre-crack elastic stage. Additionally, the study seeks to predict measured displacement values using approximate methods like the Classical Laminated Plate Theory (CLPT) and the First-order Shear Deformation Theory (FSDT). The experiment utilized six square slabs measuring 1100 mm by 1100 mm, with thicknesses of 60 mm and 90 mm. For the slabs with a thickness of 60 mm, two-way flexural reinforcing bars, each with a 10 mm diameter, were placed at 150 mm intervals, while the slabs with a thickness of 90 mm had reinforcing bars spaced at 100 mm intervals. Two of the RC slabs were strengthened with carbon plates, two with steel plates, and the remaining two served as control samples. The results indicated that steel plate strengthening improved RC slabs by 47 %, while carbon plates achieved a 43 % enhancement. Furthermore, increasing the slab thickness significantly reduced the deflection of RC slabs. A good agreement was noted when the deflection capacities predicted by the analytical model were compared to the experimental findings.