Optimizing the Use of PCE-Based Grinding Aids: The Critical Role of pH on Early-Age Cement Hydration Kinetics

Abstract

Polycarboxylate ether (PCE) water-reducing admixtures have emerged as promising solutions to optimize clinker grinding and properties. The increased adsorption ability of PCE and creation of narrow particles, despite maintaining constant Blaine fineness, has sparked the interest of their use as grinding aids (GAs) in the cement industry. This study aims at synthesizing different PCEs at three distinct pH values (i.e., 4, 7, and 9), and assessing their interactions with the cement hydration kinetics and strength development at early ages. Ten cements were produced by incorporating the synthesized PCEs at three dosage rates of 0.025%, 0.05%, and 0.1%, by weight of clinker and gypsum materials. The mixtures were tested for Fourier-transform infrared spectroscopy (FTIR) spectra, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, setting time, heat calorimetry, and early-age strength. This comprehensive analysis revealed the significant pH impact on clinker comminution and sieve residues as well as the early-age hydration kinetics, formation of hydrated products, and strength development.