Abstract:
The rapidly increasing use of high-strength concrete (HSC) is outpacing the development of appropriate recommendations for its application. A number of empirical formulae have been proposed for the prediction of the diagonal cracking shear capacity of HSC members. However, these incorporate no explicit consideration of fracture surface roughness or bond stiffness. This paper addresses this key qualitative knowledge on shear behaviour of reinforced high-strength concrete (RHSC) members. Currently, multi-directional fixed crack modeling is being used not only for design but also for maintenance. The diagonal cracking shear strength of RHSC beams, which are greatly affected by both fracture surface roughness and bond stiffness, was simulated using nonlinear finite element (FE) analysis. The test results were compared with predicted strengths using a two dimensional finite element method (2D-FEM). The average of the ratio of tested diagonal cracking shear strength to predicted was 1.04 with a standard deviation of 0.08. The multi-directional fixed crack approach was verified as a reliable structural concrete model in the case of HSC.
