Bond behaviours of deformed steel rebars in engineered cementitious composites (ECC) and concrete

Abstract This paper presents the bond behaviors of deformed steel rebars in engineered cementitious composite (ECC) and concrete under direct pullout condition. A total of 12 specimens were casted and tested, it was found that the deformed steel rebar has a much higher bond strength in ECC than in concrete due to the superior tensile ductility of ECC material. A new finite element analysis (FEA) model, which considered the influences of steel ribs, was proposed and verified with the experimental results. Based on the proposed FEA model, the failure mechanisms and bond deterioration processes for both ECC and concrete specimens were analyzed and compared. It was found that the plastic area ratio for ECC specimen was as high as 32.2%, which is 3.3 times higher than that for concrete specimen. Also, the ultimate damage zone for ECC specimen is 36% lower than that for concrete specimen. It was concluded that ECC specimen has more compatible deformability with steel rebar as more ECC elements could participate in the transfer of tensile load.