Finite element analysis of reinforced concrete and steel fiber reinforced concrete slabs in punching shear

Abstract

Punching shear capacity of reinforced concrete slabs is influenced by the following material properties: concrete compressive strength, flexural reinforcement ratio, inclusion of steel fibers in the concrete mix, and the reinforcing steel yield strength. A review of current finite element analysis models reveals that a unified approach to include all of these variables into one coherent model does not exist. This thesis presents a finite element model capable of making accurate predictions on the ultimate punching shear load and load – deflection response of a reinforced concrete slab. The model simulates the nonlinear constitutive properties of reinforced concrete by proposing a robust model to represent the behavior through the Concrete Damaged Plasticity (CDP) constitutive model. The thesis defines the parameters for the CDP model in a finite element analysis and develops an expression to mitigate mesh size dependency. A tension – stiffening model is proposed using an exponential decay expression with variables to account for varying concrete compressive strength, flexural reinforcement ratio, inclusion of steel fibers in the concrete mix, and the reinforcing steel yield strength. The model is calibrated using a series of experimental data from the literature and validated by successfully replicating the punching shear behavior of experimental specimens data from the literature.