Experimental Study of the Shear Performance of Combined Concrete-ECC Beams without Web Reinforcement.

BACKGROUND: Shear damage of beams is typically brittle damage that is significantly more detrimental than flexural damage. PURPOSE: Based on the super-high toughness and good crack control ability of engineered cementitious composites (ECC), the shear performance of concrete-ECC beams was investigated by replacing a portion of the concrete in the tensile zone of reinforced concrete beams with ECC and employing high-strength reinforcing bars to design concrete-ECC beams. The purpose of this investigation is to elucidate and clarify the shear performance of concrete-ECC beams. METHODOLOGY/APPROACH: Experimental and FE analyses were conducted on the shear performance of 36 webless reinforced concrete-ECC composite beams with varied concrete strengths, shear-to-span ratios, ECC thicknesses, and interfacial treatments between the layers. RESULTS: The results indicate that the effect of the shear-to-span ratio is greater, the effect of the form of interface treatment is smaller, the effect is weakened after the ECC thickness is greater than 70 mm (i.e., the ratio of the replacement height to section height is approximately 0.35), the shear resistance is reduced when the hoop rate is greater, and the best shear resistance is obtained when the ECC 70 mm thickness and the hoop rate of 0.29% are used together. CONCLUSIONS: This study can serve as a technical reference for enhancing the problems of low durability and inadequate fracture control performance of RC beams in shear and as a guide for structural design research.