Influence of Concrete–Rock Bonds and Roughness on the Shear Behavior of Concrete–Rock Interfaces under Low Normal Loading, Experimental and Numerical Analysis

Direct shear tests were performed to study the influence of concrete–rock bonds and roughness on the shear behavior of concrete–rock interfaces. The results of these tests show that the shear behavior of concrete–hardrock interfaces depends on the micro-roughness driving the formation of strong concrete–rock bonds and on the macro-roughness accounting for the influence of the surfaces interlocking. Based on this outcome and recent literature, a cohesive frictional model is used to simulate direct shear tests of bonded concrete–granite interfaces with the explicit representation of naturally rough interfaces. The results of these simulations show that the model has good prediction capability compared to the experimental results, opening up the pathway to numerically based robust statistical analysis.