Bond Behavior between Rebars and Hybrid Fiber Engineered Cementitious Composites

Abstract To investigate the bonding property between steel-polyethylene (PE) hybrid fiber engineered cementitious composites (HECCs) and rebar, 33 specimens were subjected to center pullout tests by using the fiber volume fraction, compressive strength, rebar diameter, and anchorage length as the controlling parameters to examine the stressing process and failure mode of the specimens. The results reveal that the addition of PE fibers negatively impacts the bond behavior between the matrix without fibers and the rebar, whereas the ultimate bond strength increases gradually with the increase of steel fiber content. In addition, the ultimate bond strength was positively correlated with the compressive strength of HECC. In this study, the ultimate bond strength did not change significantly with increasing rebar diameter. In addition, the uneven distribution of bond stresses along the anchorage length results in a smaller ultimate bond strength for larger anchorage lengths. To simplify the engineering application of HECC, the equations for calculating the ultimate bond strength of HECC are proposed based on the test results; the calculated values of the critical anchorage length and ultimate anchorage length of HECC are also provided.