This paper investigates the flexural performance of engineered cementitious composite (ECC) concrete
beams reinforced with innovative hybrid bars. Hybrid bars combine the advantages of both FRP and steel
bars in enhancing the ultimate strength, ductility, and corrosion resistance compared with pure FRP or
steel bars. Twelve half-scale ECC-concrete beams were tested to study the flexure behaviour under
four-points loading test using polyvinyl alcohol (PVA) ECC fibers. Polyvinyl alcohol (PVA) fibers were used
in the ECC mix for this purpose. The experimental variables are the hybrid reinforcement ratios (0.85%,
1.26%, and 1.7%), PVA fiber ratio (0.0%, 0.75%, and 1.5%) and hybrid schemes (hybrid and GFRP bars).
The test results showed significant enhancement in the capacity of ECC concrete beams reinforced with
hybrid bars or hybrid schemes. The achieved enhancements are 12% and 27% for PVA ratio of 0.75% and
1.5% respectively. In the presence of PVA fibers, the ultimate strain of the bars is higher than that registered
in the absence of PVA fibers. Non-linear finite element analysis (NLFEA) was carried out to validate
the experimental results. The NLFEA is adequately simulating the experimental results. Nominal flexural
strength and flexural rigidity were assessed with the experimental test results and validated with 77
available ECC-concrete beams from the literature. The validation proved that the assessments of the nominal
flexural strength and flexural rigidity are performed well in the prediction. Finally, a comprehensive
sensitivity study is conducted to illustrate the effect of PVA-ECC on the flexural rigidity of the beams. The
experimental evidence presented in the current study demonstrates the feasibility and plausible future of
the novel hybrid bars and PVA fibers especially for marine and waterfront concrete structures. |
