Effects of concrete-stirrup interaction on shear behavior of RC beams under varying shear span-depth ratio scenarios

The shear failure of steel-reinforced concrete (RC) beams poses a critical threat to structural integrity and human safety, given its inherently brittle nature and lack of premonitory signs. Consequently, comprehending the intricate concrete-stirrup interaction mechanism holds substantial importance. Such understanding facilitates the advancement of robust structural systems, optimization of construction design, and identification of potential failure modes. In pursuit of this objective, this study proposes a simple and cost-effective approach to analyze the interplay between cementing force, friction resistance, and mechanical interaction at the concrete-stirrup interface, considering a diverse range of shear span-depth ratios. Experimental results indicate that the favorite concrete-stirrup interaction can facilitate the load transfer between concrete and intersected stirrups, resulting in a notable reduction in concrete crack width (by 9.1%−57.1%) and a considerable shear contribution of concrete (by 0.3%−4.7%) and stirrups (by 0.3%−3.1%), as well as a substantial enhancement in structural shear capacity (by 0.3%−39.9%). The outcomes of this study yield useful information for engineers on the crucial role of favorable concrete-stirrup interaction in the advanced shear performance of RC beams. © 2024 Institution of Structural Engineers