Effect of structural modification of polycarboxylate-based grinding aids on hydration kinetics and rheological properties of cementitious systems

Studies have examined the effects of polycarboxylate ether-based admixtures (PCEs) on clinker grinding, cement properties, and overall system performance; however, the influence of variations in chain structure and charge distribution on cement interactions remains insufficiently understood. To address this gap, the present study evaluates the effects of PCEs with controlled modifications in main chain length, side chain length, and anionic/non-ionic charge ratio on cement particle size distribution, fresh-state properties, hydration kinetics, and compressive strength. Seven distinct PCE-type grinding aids (GAs) were synthesized, and 22 cement samples were produced at three GA dosages, including a GA-free control. The mechanism of PCE-based GA action was investigated through analyses of particle size distribution, hydration kinetics, water-reducing admixture adsorption, rheological properties, setting time, and compressive strength. These findings provide new insight into the mechanisms governing the performance of PCE-based GAs. The results indicate that cements produced with PCEs featuring medium main and side chain lengths or a medium chain combined with a high anionic/nonionic ratio exhibit improved hydration kinetics and rheological properties. Overall, the study demonstrates that PCEs with an optimal chain length and a high anionic/non-ionic ratio deliver superior performance across the evaluated properties.