Shear Strength of Ultra-High-Performance Concrete Beams with Small Shear Span-Depth Ratios

Ultra-high-performance concrete (UHPC) has been gradually used in structural engineering due to its excellent mechanical performance; however, predicting the shear strength of UHPC beams is still a challenge, especially for beams with small shear span-depth ratios. To address this issue, this paper is devoted to developing a rational model to predict the shear capacity of UHPC beams with stirrups. The shear-resisting mechanism of UHPC beams has been revealed and the contributions of compression zone and dowel action on shear strength have been presented. Combined with the for shear capacity assessment has been presented. Twelve UHPC beams were designed and tested to validate the proposed model. The proposed method has been verified and can be used to predict the shear capacity and average diagonal crack width of UHPC beams with satisfactory accuracy, while the current design codes, including SETRA-AFGC and SIA, give conservative shear strength for UHPC beams when the shear to span is less than 2.5. Moreover, the contributions of compression zone and dowel action are found to be 32 and 17% for UHPC beams with small shear span-depth ratios.