Engineered cementitious composites (ECC) possesses prominent mechanical properties and low density, which is expected to be applied in high-performance lightweight structures. Unfortunately, ECC owns high preparation cost owing to the utilization of a large amount of fibers and binder materials. To realize light weight and lower cost, steel reinforced ECC hollow beams without web reinforcement were proposed in the current research. The shear responses of ECC hollow beams were experimentally studied. A total of twelve beams with various hollow ratios (i.e., 0%, 3.14% and 12.56%) and matrix materials (i.e., 0.22, 0.27 and 0.32 in the water-to-binder ratio of ECC or mortar) were tested by three-point bending. Digital image correlation (DIC) system was applied for recording crack development during the shear test. The results demonstrated that some ECC hollow beams possessed larger shear capacity and better ductility in comparison with ECC solid beams. The prediction model for the shear capacity of ECC hollow beams was put forward through considering the role of fibers, and the predicted results were well matched to the experimental results. The failure mechanism and hollow shape effect (i.e., square, triangle and circle hollow) of ECC hollow beams were analyzed through finite element software. At the same hollow ratio, ECC beams with circle hollow possessed larger shear capacity when compared with ECC beams with square or triangle hollow. Furthermore, the economic efficiency and composite performance of these beams were evaluated. The proposed composite index considering bearing capacity, cost and weight indicated that compared with ECC solid beams and mortar hollow beams, ECC hollow beams held superior comprehensive performance. This study laid the cornerstone for the engineering utilization of steel reinforced ECC hollow beams without web reinforcement.
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