Bearing capacity of seawater sea sand recycled aggregate concrete beams reinforced with glass fiber reinforced polymer bars

In this study, seawater, sea sand and recycled coarse aggregate (RCA) are combined to prepare seawater sea sand recycled aggregate concrete (SSRAC) for use in beams. Nine beams are reinforced with glass fiber reinforced polymer (GFRP) bars, while 2 more beams are reinforced with steel bars for comparison. Unlike reinforced concrete (RC) beams that contain steel bars, SSRAC beams reinforced with GFRP bars (GFRP-SSRAC) are less stiff and ductile. For GFRP-SSRAC beams with a certain shell particle content in this study, the use of seawater and sea sand in concrete decreases the cracking load. The ultimate load is smaller overall for GFRP-SSRAC beams than RC beams with the same reinforcement ratio. The predictions of flexural capacities made using the ACI code are all lower than the test results. When the replacement ratio of RCA is 100%, the predictions for RAC/SSRAC beams using the Chinese code are lower than the measured values. Finally, the measured stress-strain curves of SSRAC and GFRP bars are used to obtain the moment-curvature relationships according to reinforcement-based and concrete-based calculation methods. These calculations and results are discussed in this paper.