Coarse Aggregate Size Effect on Non-linear and Uncertainty Mechanical Behaviors for Concrete

Abstract

A series of uniaxial compression tests and simulations were conducted to evaluate the influences of single coarse aggregate (CA) size on the mechanical properties of concrete and their uncertainties. In this research, the specimens of pure mortar matrix and specimens with diameter 15 mm and 30 mm of single spherical steel aggregate were fabricated and tested by a material testing system. Based on experimental results, the mechanical parameters, including the elastic modulus, compressive strength, strain at the peak stress and absorbed strain energy were investigated. It was found that larger size of CA results in higher elastic modulus and compressive strength. Meanwhile, the strain at peak stress and absorbed strain energy of concrete are non-linear with the size of CA. And then, the mechanical properties were analyzed in the aspect of ITZ which is closely related to the size of CA. In addition, simulation results were presented to discuss the stress distribution of different size CA in specimen. In conclusion, the CA size has significant effect on the uncertainty of elastic modulus, strain at the peak stress and absorbed strain energy, but has little effect on the compressive strength. The findings from the current study will help gain the insights into the non-linear and uncertain mechanical behaviors of concrete.