Numerical Method for Predicting Young’s Modulus of Concrete with Aggregate Shape Effect

Abstract

Owing to its importance to the structural analysis and design of cement-based materials, it is essential to determine Young’s modulus of concrete. This paper presents a numerical method for predicting Young’s modulus of concrete with aggregate shape effect. In the numerical method, aggregate particles are assumed to be elliptical and distributed within a rectangular concrete element with periodic boundary conditions by introducing an overlap criterion for two elliptical aggregate particles. The method modifies the lattice model to take account of the mechanical properties of each phase constituent of concrete in the analysis of stress. After the validity of the developed numerical method is verified with three independent sets of experimental results, the effects of the maximum aggregate diameter, aggregate gradation, interfacial transition zone (ITZ) thickness, and aggregate shape on Young’s modulus of concrete are evaluated in a quantitative manner. It is found that Young’s modulus of concrete increases with the increase of the maximum aggregate diameter and aggregate aspect ratio but decreases by increasing the ITZ thickness. It is also found that the aggregate gradation has a significant influence on Young’s modulus of concrete. The paper concludes that the numerical method developed in the paper can predict Young’s modulus of concrete with an average relative error smaller than 7%.