The Effects of High-Performance Concrete on Shear Strength of Reinforced Concrete Beams without Transverse Reinforcement

The use of high-performance concrete (HPC) with a compressive strength higher than ۵۰ MPa has increased significantly in recent decades. Compared to normal strength concrete (NSC), HPC has improved properties. However, the higher strength of the concrete leads to increased member brittleness and smoother shear failure surfaces. If a beam is not well designed, under further loading, shear failure can occur in a brittle and sudden manner without warning. Correct prediction of the shear behavior is essential to prevent the brittle and sudden collapse of the building.Current design codes are based on tests conducted on models with a concrete compressive strength lower than ۴۰ MPa. HPC beams behave differently from NSC beams. Therefore, the use of NSC design relationships for HPC beams, can lead to non-conservative designs. The purpose of this paper is to investigate the effects of using HPC in shear design relationships and to find the most appropriate formula for predicting the shear capacity. The design formula used in this research includes the ACI ۳۱۸ code, Australian Standard and ۱۴ proposed formulas by other researchers for HPC beams. To verify the validity of these design methods, ۱۱۵ test results from the literature were selected to compare with formulas.

Keywords:

beams without stirrups , high performance concrete , high strength concrete , shear strength , shear strength relationships.