AbstractThis paper presents the results of an experimental study carried out to evaluate the structural behavior of precast concrete culverts reinforced with glass fiber–reinforced polymer (GFRP) bars. Five full-scale GFRP reinforced large culverts having a clear span of 1,530 and 960 mm high were tested under different combinations of lateral and vertical loads. The general behavior of the culverts including crack pattern, force-displacement behavior, ultimate capacity, and failure mode were evaluated and analyzed. The behavior of the culverts at the serviceability limit state were also monitored in terms of crack width and deflection. Punching shear failure at the top slab was found to be the typical mode of failure in all of the culverts tested. Failure was characterized by crushing of concrete with no rupturing of the longitudinal GFRP-reinforcement. The results indicated that GFRP-reinforced concrete culverts have an acceptable load-carrying performance with a small residual deflection and crack width. The presence of the lateral load, simulating the effect of soil, resulted in upward deflection (hogging) of the culverts and increased the load-carrying capacity of the culverts. Maximum deflections were observed when two walls of the culverts were unrestrained. The experimental study presented here indicated that serviceability limit state (deflection and crack width) rather than the strength governs the design of GFRP-reinforced concrete culverts. This study showed that GFRP can be a suitable alternative to steel for precast concrete culvert application, especially in aggressive environments where steel bars are vulnerable to corrosion.