Impact of PCE-based grinding aids on hydration kinetics in fly ash substituted systems: Influence of pH and dosage

Abstract

While the use of grinding aids (GAs) is commonly favored for their cost and energy efficiency benefits, these additives can also present challenges, such as incompatibility with water-reducing admixtures. This has led to interest in polycarboxylate-based water-reducing admixtures (PCEs) as potential grinding aid (GA). However, there is a significant gap in the literature concerning the interaction between these PCE-based GA properties and cementitious systems' morphological characteristics and hydration kinetics. This study investigated the effects of PCE-based GAs with varying pH levels on hydration kinetics, flowability, and compressive strength in cementitious systems containing fly ash. PCE-based GAs were synthesized at three different pH levels (4, 7, 9), while other parameters were held constant. Using these GAs, a total of 10 Portland cements, including one control, were produced at three different dosages. Additionally, two different fly ash substitution levels were used to prepare paste and mortar mixtures with these cements. This approach has enabled the investigation of fly ash substitution systems in the presence of PCE-based GAs and the assessment of environmental impact through life cycle analysis. The study aimed to contribute to the existing literature and offer an alternative approach to sustainable production. The findings revealed that the PCE-based GA with a low pH value (4) was the most optimal in terms of the evaluated properties.