Resistance of reinforced concrete members with hollow circular cross-section under combined bending and shear - Part II: New calculation model

Part II analyses the applicability of current shear design models for RC members with a hollow circular cross-section on the basis of experimental results introduced in Part I of this paper. A new calculation model is proposed which assigns the contribution of the concrete zone in compression to shear resistance. The proposed model takes into account how the flexural and shear reinforcement, the load-to-support distance and the shape of the cross-section affect the shear resistance.
The model is based on the analysis of potential failure sections subjected to bending and shear, and applies a compatibility criterion that considers how the member carries the load. The analogy between the failure of the concrete compression zone and the failure of the soil along a sliding surface are presented as well as the conditions for the development of the failure section.