Finite element modeling of the interfacial behavior at surface roughness concrete without the projecting steel

Abstract

The development of composite action between precast concrete slab and concrete toppings is important to provide a monolithic behavior of composite concrete. The current Eurocode 2 provides design expression for interface shear strength of both concrete base and concrete topping. In this paper, the finite element modeling is presented and calibrated with experimental results. The interface shear strength between precast concrete slab and cast-in place concrete topping slabs was evaluated through a set of 9 push-off experiments. Finite Element Modeling package ABAQUS 6.12 was used to model the interface bond of concrete-to-concrete layers. The push-off test specimens featured segments of precast concrete slabs sized 300 mm × 300 mm × 100 mm with a variety of surface textures including trowel finished, indented and wire-brush roughened. A cast-in place concrete was poured on top of the concrete base to form a 300 mm × 300 mm × 75 m concrete topping. Failure of the bonded interfaces was modeled with cohesive zone model (CZM) approach with zero thickess interface element. The parameters used in the analysis include interface shear strength, fracture energy and elastic shear stiffness. The study shows that the difference between the model and experimental results is relatively small and therefore shows the capability of the finite element modeling to carry out interface analysis.