Abstract:

This study investigates the behavior of SCC hollow beams reinforced by GFRP bars, which have lighter weight, lower cost, and high corrosion resistance compared to conventional steel reinforcement. Eighteen SCC beams with dimensions of (1200×225×150) mm were divided into three groups. Each group had 5-beams according to the types of stirrups (steel, (full, 2L-, 4bar, and 4U) GFRP)) stirrups in all groups with three reference beams. The longitudinal reinforcement was 6Ø10mm steel bars, 6Ø10mm GFRP bars, and (3steel+ 3GFRP) bars for the first, second, and third groups respectively. All beams were SCC concrete with a longitudinal rectangular hollow (50×100) mm. The results showed that the ultimate load of a hollow beam was decreased by the ratio of (13%, 11%, and 8%) compared to the first, second, and third groups respectively. In the first group, the ultimate load of a hollow beam reinforced with (steel stirrups) increased by about (3%), (6%), (21%), and (11%) compared to the hollow beam reinforced with (full, 2L, 4bar, 4U-bar) GFRP stirrups respectively. In the second group, the ultimate load of a hollow beam reinforced with (steel stirrups) increased by about (4%), (9%), (49%), and (14%) compared to the hollow beam reinforced with (full, 2L, 4bar, 4U-bar) GFRP stirrups respectively. In the third group, the ultimate load of a hollow beam reinforced with (steel stirrups) increased by about (3%), (6%), (23%), and (14%) compared to the hollow beam reinforced with (full, 2L, 4bar, 4Ubar) GFRP stirrups respectively. The best case, according to the ultimate load among the stirrups, was steel stirrups, which gave the highest shear strength compared to the other stirrups because of the low elasticity of the GFRP stirrups. While compared to the other GFRP stirrups, GFRP full stirrups had the highest shear strength because there is one connection point compared to two or four connecting points for other types.

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