A multi-scale investigation on recycled ceramic and rubber composite cement-based materials: Acoustic emission, NMR, molecular dynamics simulation

Abstract

Utilizing construction waste has become a promising way to reduce carbon emissions and energy consumption. This study systematically investigated the application potential of ceramics waste aggregate (CWA) in rubber cement-based materials from the macro-micro-nano scale. The results show that CWA and rubber particles can synergistically enhance the mechanical strength and ductility of mortar. The 28-day compressive and flexural strength of composite mortar increased by 42.9% and 33.3%, respectively. The active pozzolanic components (SiO2, Al2O3) of CWA induce the secondary hydration reaction, and the cement hydration degree could be increased by 33.8% at 28 days. Furthermore, the "charge non-conservation phenomenon" driven by Si4+ and Al3+ promotes the polymerization of the three-dimensional gel network, increasing the proportion of Q3 and Q4 species. The penetration of H2O, Ca2+, and silicon chains into the CWA crystals strengthens the mechanical coupling between the slurry and the aggregate at the nano-scale. Nevertheless, the deterioration of workability and the bonding slip of ceramic glaze increase the brittleness of mortar.