Mechanical properties, microstructure and seawater corrosion resistance of alkali-activated slag cementitious materials: The role of polyacrylate emulsion, silicone-acrylate emulsion, styrene-acrylate emulsion

This study investigates the impact of emulsion modifications using polyacrylate (PA), silicone-acrylate (SiA), and styrene-acrylate (StA) on the properties of alkali-activated slag cementitious materials (AAS), and conducts a simulated seawater corrosion experiment. The results demonstrate that the optimal dosage of SiA emulsion is 2 %, with a 28-day compressive strength of 75.23 MPa, representing an increase of 13.82 %. The coupling effect of Cl - , SO 4 2- , and Mg 2+ ions in seawater expedites the deterioration of the material. The synergistic effect of Mg 2+ and SO 4 2- gives rise to a new corrosion product, ettringite (AFt), which accelerates the degradation of the cementitious material. After 10 dry-wet cycles, compared with the blank group, the compressive strength retention rate of the modified and enhanced samples has increased by 346.74 %. The ester groups of the acrylate emulsion can form a compact “interpenetrating” network with C-(A)-S-H gel, with Ca 2+ serving as the key cross-linking point. SiA emulsion particles possess a distinctive core-shell structure, with the shell being an acrylate polymer and the core being a silane structure. The hydrolysis of silane groups generates silanol groups that can polymerize with Si-OH and Al-OH groups in aluminosilicates, forming a stronger cross-linking structure. Consequently, SiA emulsion exhibits the best modification effect, which can augment the hydrophobicity of the system, reduce the transport of harmful ions, and suppress the formation and expansion of microcracks through intercalation and bridging actions, thereby reducing internal defects and enhancing corrosion resistance. • Comparison of the modification mechanisms of three types of acrylate emulsions. • The coupling erosion mechanism of Cl - , SO 4 2- , and Mg 2+ . • Enhanced reaction of silanol groups in silicone-acrylate emulsion. • Highly efficient anti-seawater corrosion.