Synergistic effects of SAE/CaCO3 on enhancing sulfate resistance in High-Strength cementitious composites

Abstract

Abstract The composite incorporation of polymer and calcium carbonate (CaCO3) in cementitious matrices demonstrates effective toughening effects on high-strength cementitious composites (HSCC). However, its resistance to salt ion erosion remains unverified, which is critical for construction materials in coastal environments and underground engineering. This study systematically evaluates the sulfate attack resistance of SAE/CaCO3 modified HSCC through mass variation analysis, ultrasonic monitoring, durability coefficient determination, and surface morphology characterization. Advanced microstructural investigations including MIP, XRD, DSC, and SEM were employed to elucidate the synergistic mechanisms of SAE/CaCO3 in enhancing durability of the cement matrix. Results reveal that SAE/CaCO3 modified HSCC exhibits exceptional sulfate resistance. Specifically, under sulfate attack, high-SAE dosage specimens showed lower mass fluctuation and less mechanical property degradation compared to control groups. The primary mechanism stems from SAE-induced pore structure refinement. This study elucidates critical structure-performance relationships in SAE/CaCO3 modified HSCC systems, offering dual benefits of special engineering environment durability enhancement and mechanistic insights for polymer-cement composite optimization.