Study on the mechanical strength and durability of polymer-based underwater non-dispersible cement pastes

This study conducted detailed research and analysis on the setting time, compressive strength, bond strength, and bond splitting tensile strength of anti-washout cement with polyacrylamide (PAM) content. The results indicate that the initial and final setting times of the paste show a linear increasing trend with PAM addition. The early compressive strength exhibits a significant reduction, while the growth rate of compressive strength from 7 d to 28 d markedly accelerates after overcoming the hydration barrier. Compared to land-cast specimens, underwater-cast calcium sulfoaluminate cement and ordinary Portland cement show limited reductions in compressive strength and splitting tensile strength. However, due to the effects of adsorbed water films and alkali metal leaching, their bond splitting tensile strengths decrease by 40.30 % and 70.42 %, respectively. The chloride penetration depth and non-steady-state chloride migration coefficient (DRCM) are reduced by approximately 34 % and 42 %, which correlates with PAM-induced reductions in hydration porosity and structural connectivity of the specimens.