Experimental evaluation of flexural behavior of HPFRCC beams reinforced with hybrid steel and GFRP bars

In this paper, seven beams were reinforced with the steel and Glass Fiber Reinforced Polymer (GFRP) bars in a hybrid system and the experimental behavior of beams was investigated. Three groups of beams were reinforced, including only-GFRP, only-steel, and hybrid steel-GFRP rebar subjected to four-point bending tests, respectively. To enhance the ductility of beams, conventional concrete was substituted with the High Performance Fiber Reinforced Cementitious Composites (HPFRCC). The beams of the first and second group were separately constructed by conventional concrete and HPFRCC; however, the third group was only consisted of HPFRCC. Moreover, the beams were reinforced in proportion to the percentages of the balanced ratio of longitudinal rebar. The results indicated that HPFRCC concrete positively influenced on the strength, ductility, and energy absorption of reinforced beams using composite and hybrid bars. The flexural capacity of hybrid reinforced concrete beams was between 86 and 115% of only-GFRPs and between 47 and 63% of only-steel beams and their ductility was between 88 and 235% compared to only-steel fiber reinforced concrete beams. Energy absorption in only-GFRP and only-steel samples were 50 and 34% compared to the hybrid beams. In hybrid beams, the higher ratios of effective (Psf ,f) was, the greater energy absorption was observed.

Automated summary

In this study, the experimental behavior of beams reinforced with a hybrid system of steel and GFRP bars was investigated. Results showed that HPFRCC concrete positively influenced the strength, ductility, and energy absorption of the reinforced beams using composite and hybrid bars.