Predictions for the Multiscale Elastic Performance of Solid Waste Aggregate Concrete

To investigate the elastic properties of bulk solid waste aggregates and their impact on the elastic performance of mixed concrete, mechanical tests were conducted on 32 types of natural and solid waste aggregates, along with their corresponding mixed concretes and internal mortars. These tests were complemented with X-ray diffraction (XRD), scanning electron microscope (SEM), mercury intrusion porosimetry (MIP) analyses, microhardness assessments, and a discrete-element simulation. The results show that the elastic modulus of coarse aggregates significantly influences the overall elastic modulus of concrete, more so than that of the mortar and interfacial transition zones. The secant modulus, derived from the standard aggregate crushing value test, substantially reflects the actual elastic properties of the bulk aggregates within concrete, thus enabling rapid predictions of multiscale elastic performance of concrete. Furthermore, incorporating a water influence coefficient into the predictive model not only enhances prediction accuracy but also aids in identifying aggregates prone to softening within the concrete.