TY - JOUR T1 - Interaction of Polycarboxylate-Based Water-Reducing Admixture Molecular Structure with Fly Ash Substituted Cementitious Systems: Marsh-Funnel and Mini-Slump Performance AU - Kobya, Veysel AU - Mardanı, Ali PY - 2023 DA - December DO - 10.55549/epstem.1412488 JF - The Eurasia Proceedings of Science Technology Engineering and Mathematics JO - EPSTEM PB - ISRES Publishing WT - DergiPark SN - 2602-3199 SP - 693 EP - 699 VL - 26 LA - en AB - Polycarboxylate ether-based high-range water-reducing admixtures (PCE) play a crucial role in enhancing the workability of fly ash-substituted cementitious systems. Alterations to the chemical structures of both the main and side chains can particularly enhance the electrostatic repulsion and steric hindrance effects of PCEs. As a consequence, this results in improved performance within cementitious systems containing fly ash substitutions. This study investigated the compatibility of the altered molecular structure of polycarboxylate ether (PCE) with cementitious systems containing fly ash substitutions. To achieve this, five polymers were synthesized, varying the side chain length, molecular weight, main chain length, and main chain lengths of PCEs while maintaining other properties constant. Cement pastes were then prepared using the synthesized PCEs with fly ash replacements at three different rates. Marsh-funnel flow time and mini-slump values were measured in the prepared mixtures. The study revealed that in mixtures without fly ash, PCEs with a long main chain (40k) and short side chain length (1000 g/mole) exhibited the lowest Marsh-funnel flow and mini-slump performance among PCEs with diverse molecular structures. For the other PCEs in these mixtures, the change in molecular structure did not significantly affect their performance. However, as the fly ash replacement rate increased, PCE having a medium main chain (21k) and side chain (2400 g/mole) length outperformed other PCEs in terms of Marsh-funnel flow and mini-slump performance. KW - Fly ash replacement rate KW - Polycarboxylate-based water-reducing admixture (PCE) KW - change in PCE side chain length KW - change in PCE main and side chain length CR - Altun, M. G., Ozen, S., & Mardani-Aghabaglou, A. (2021). Effect of side chain length change of polycarboxylate-ether–based high-range water–reducing admixture on properties of cementitious systems containing fly ash. Journal of Materials in Civil Engineering, 33(4), 04021015. CR - Altun, M. G., Ozen, S., Karakuzu, K., Mardani, A., & Ramyar, K. (2023). Single and multi-effects of polycarboxylate main and side chain lengths on setting time, viscosity, and yield stress of cementitious mixtures containing fly ash. Journal of Materials in Civil Engineering, 35(7). 04023204. CR - Kantro, D. L. (1980). Influence of water-reducing admixtures on properties of cement paste—a miniature slump test. Cement, Concrete, and Aggregates, 2(2), 95-102. UR - https://doi.org/10.55549/epstem.1412488 L1 - https://dergipark.org.tr/en/download/article-file/3631024 ER -