Flexural strengthening of RC one way slabs with high-performance fiber-reinforced cementitious composite laminates using steel and GFRP bar

This experimental study aims to evaluate the contribution of the High-Performance Fiber-Reinforced Cementitious Composite (HPFRCC) laminate with steel and GFRP bars to the flexural behavior of RC slabs. In this study, the HPFRCC material was first investigated to determine the mix proportion. HPFRCC laminates with and without longitudinal steel reinforcements were then tested. Finally, strengthened slabs were investigated by four-point flexural testing. The experimental results were suggestive of the effect of the properties of the HPFRCC laminate, including its application procedure, steel fiber volume fraction, incorporation of longitudinal reinforcement, and the type of reinforcement (steel or GFRP bars), on the increase in the load-bearing capacity of the slab. Adding longitudinal bars to the HPFRCC laminate improved the weaknesses of the crack pattern, loadcarrying capacity, ductility, and stiffness. HPFRCC-laminate strengthening enabled a 92-326% increase in the load-bearing capacity of the slabs. This experimental undertaking is the first time that the HPFRCC laminate is reinforced with GFRP, successfully, with satisfactory results. Analytical models were developed to predict the flexural capacity of the one-way slab strengthened using HPFRCC laminate and the experimental results compared to the predicted theoretical models. Analytical and experimental results showed excellent consistency with an average difference of 6% and a maximum of 18%.