Mechanical behaviour of coarse, lightweight, recycled and natural aggregates for concrete

In this study the application of the single-particle compression test is discussed as an alternative method for the mechanical characterisation of coarse aggregates generally employed in concrete manufacturing. This leads to an estimation of the tensile strength and fracture energy of the aggregate particles. A wide range of aggregate types is considered. In particular, the mechanical responses of crushed limestone and river gravel are compared with expanded clay, recycled concrete and clay brick aggregates. In addition, physical properties are assessed experimentally and correlated to the aggregates' mechanical performance. Despite the high data scatter presented, the results demonstrate the ability of the proposed approach to accurately determine fracture energy and strength histories using single-particle compression. Overall, the porosity governs the mechanical behaviour of particles. Moreover, direct relationships between mechanical and physical properties yield consistent and expected results that validate the methodology.