Enhanced contact model for shear friction of normal and high-strength concrete

The aim of this paper is to suggest a rational, yet simple, methodology for obtaining shear friction capacity of both normal and high-strength concrete (HSC). The approach considers the following factors: interface morphology (roughness), concrete strength, amount of reinforcement crossing the interface, and normal stress applied to the interface. The interface roughness is probabilistically idealized according to the contact density model developed by Li and Maekawa.¹ The relation between interface roughness and concrete strength is established based on a fracture energy approach. Finally, the suggested methodology is compared with ACI 318-95,² Mau and Hsu,³ and the Canadian Code.⁴.