Research on the Coupled Deterioration Mechanism of Ship Lock Concrete Under Surface Wearing and Carbonation

Ship lock concrete is simultaneously subjected to surface wearing and carbonation under service, yet the coupled deterioration mechanism has not been systematically clarified. In this study, an equivalent cycling test is established to elucidate the synergistic effect of surface wearing and carbonation on carbonation kinetics, pore structure development and mechanical performance. By employing micro-hardness profiling, the thermogravimetric analysis (TGA), mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM), the coupled mechanism is revealed and a carbonation model of ship lock concrete under the influence of surface wearing was established. Results show that surface wearing significantly promotes ship lock carbonation, which is confirmed by the increasing carbonation depth and surface densification. Meanwhile, the changes in concrete porosity and carbonation products further emphasize the promoting effect of surface wear on carbonation. Accordingly, the carbonation showed a persistently accelerated deterioration pattern. By revealing the coupled deterioration mechanism of surface wearing and carbonation, this study systematically provides theoretical insights into the durability of ship lock concrete.