Prediction of Size‐Dependent Maximum Loads of Concrete Beams

Abstract

A simple analytical model has been developed for prediction of size‐dependent maximum loads of concrete‐beam specimens subjected to mode‐I rupture. The analytical model is cast within a framework of a fictitious crack model, but incorporating the following simplifying assumptions: (1) The tension‐softening law is linear; (2) the crack‐opening profile remains linear throughout the fracture process; (3) the resultant cohesive force is acted at an approximate, yet constant, location; (4) the stress distribution in the ligament of the beam specimens is described by a quadratic function; and (5) a simplified compliance equation is adopted to relate the crack opening to the applied loads. The model requires input of four material properties: Young's modulus, Poisson’s ratio, threshold separation, and tensile strength. Model predictions were compared with experimental data as well as numerical simulations. The favorable comparisons suggest that, instead of a number of simplifying assumptions made in the formulation, the model can be used as a practical tool for analysis purposes.