Cyclic behavior of GFRP-reinforced concrete one-way slabs with synthetic fibers

This paper investigates the cyclic behavior of one-way glass fiber-reinforced polymer (GFRP)-reinforced concrete (GFRP-RC) slabs incorporating synthetic fibers. The study aims at improving the performance of GFRP-RC slabs both at serviceability (SLS) and ultimate limit states (ULS). A total of 8 slabs were tested under cyclic bending and the effect of fiber type (polypropylene (PP) and polyvinyl alcohol (PVA)), fiber dosage (0, 0.5%, and 1.0%), and the type of reinforcement (steel and GFRP) was investigated. The comparison and evaluation of the slabs’ behavior was made in terms of crack width and deflection performance, ductility, failure mode, and overall load and deflection capacity. The results showed that the effect of fibers was more pronounced in GFRP-RC slabs compared to steel-RC slabs, both at the SLS and ULS. This is due to their reduced neutral axis depth as a result of the lower elastic modulus GFRP bars. Moreover, the fibers were found to reduce crack widths and deflections and enhanced the energy absorption; however, they did not significantly enhance the ductility of the slabs. The addition of fibers also resulted in an elastic response with most of the total applied deflection recovered at the end of each cycle of loading. Compared with steel-RC members, the cost of repair of GFRP-RC members seems to be relatively lower because of the reduced permanent deflection of the slab.