Influence of strain-rate and confining pressure on the shear strength of concrete

Abstract

The paper presents an experimental method used to investigate the shear behaviour of concrete and rock-like materials in quasi-static and dynamic loading. This method is based on the use of Punch-Through Shear (PTS) specimen and a passive confining cell. PTS sample is a short cylinder in which two cylindrical notches are performed. The displacement of the central zone beside the peripheral zone produces a shear fracture in the ligament. Metallic (steel or aluminium) confining ring allows inducing a confining pressure in the fractured zone due to the dilating behaviour of concrete under shear deformation. The experimental configuration has been designed through a series of numerical simulations in which the Drucker-Prager plasticity model is used for modelling the concrete behaviour. Computations showed the necessity to practice radial notches in the peripheral zone of the sample for deducing the radial stress in the ligament from data of strain gages glued on the outer surface of the confining ring. Finally this experimental method was employed to analyse the strain-rate and pressure sensitivity of dry and wet concrete under shear loading.