Shear behavior of RC beams strengthened with high-strength steel strand mesh reinforced ECC: Shear capacity, cracking and deformation

An experimental and theoretical study on the shear behavior of reinforced concrete (RC) beams strengthened with high-strength steel strand mesh reinforced engineered cementitious composites (HSSM-ECC) was reported in this paper. Four-point bending test was performed on a total of ten strengthened beams and three referential beams, considering the test variables of the shear-span ratio, the reinforcement ratio and diameter of HSSM, the water-binder ratio and thickness of ECC layer, and strengthening configuration. Test results showed that the shear performance of the strengthened beams was significantly enhanced, and the multi-cracking pattern was observed in the strengthened beams, which effectively reduced the crack width and the brittleness of RC beams in shear. In addition, the effect mechanism of test variables on the shear behavior of strengthened beams was discussed in detail. Finally, considering the effects of dowel action of longitudinal rebars and flexural-shear combination, a comprehensive analysis model for predicting shear capacity, shear deformation, and maximum shear crack width based on modified compression field theory was proposed, which was found to be acceptable for more accurate prediction of shear capacity, shear deformation, and maximum shear crack width of strengthened beams by comparing with the test results and other existing models.