Uniaxial compressive properties of ecological concrete: Experimental and three-dimensional (3D) mesoscopic investigation

Abstract

In this study, the uniaxial compressive behaviors of ecological concrete were investigated using experimental and numerical methods. The uniaxial compressive test was performed on the cubic specimens with a side length of 150 mm. The three-dimensional (3D) mesoscopic model with the consideration of random shapes and sizes of aggregates was developed. The parameters considered were the aggregate-to-cementitious material ratio (A/C), the water-to-cementitious material ratio (W/C), the aggregate size, and the void content. The results indicate that the collapse of aggregate caused by the sliding failure of bonding points among aggregates is the main failure mode of ecological concrete under uniaxial compression. The void content and compressive strength of ecological concrete are associated with the A/C and W/C, and the A/C of 6 is suggested as the optimal value. The compressive stress-strain curve consists of three parts, in which the platform period represents the yield period that is relative to the compacting process. Besides, the peak stress and the peak strains in the axial- and lateral directions are related to the void content and aggregate size, and the lateral strain is obviously larger than the axial strain. Through the comparison of numerical and test results, the developed 3D mesoscale modelling approach together with the model parameters has been approved in investigating the compressive behaviors of ecological concrete.