Title: Use of Water Reducers to Improve Grindability and Performance of Portland Cement Clinker

Author(s): Joseph J. Assaad and Salim E. Asseily

Publication: Materials Journal

Volume: 108

Issue: 6

Appears on pages(s): 619-627

Keywords: Cement; clinker; grinding aids; water reducers.

DOI: 10.14359/51683465

Date: 11/1/2011

Abstract:
A comprehensive research project was undertaken to evaluate the effect of liquid or powder water reducers (WRs) on the grindability and clinker factor optimization during the production of portland cement. Three WRs based on lignosulfonate (LS), polynaphthalene sulfonate (PNS), and polycarboxylate (PC) were tested at various concentrations. The efficiency of WRs to preserve their waterreduction properties following the grinding energy and rise of temperature encountered in the grinding mill was quantified. Regardless of the type of WR, test results have shown that the incorporation of increased concentrations, whether in liquid or powder forms, can improve grindability of clinker while at the same time reduce water demand. All mortars prepared with the high-range water-reducing admixture cement exhibited higher compressive strengths compared to the ones made with the control cement due to a decrease in the water cement ratio (w/c) and an improvement in cement fineness. For a given dosage, cement ground with PC-based WR exhibited the highest levels of strength increase. The clinker factor and grinding energy were found to be simultaneously optimized by up to 32% and 5%, respectively, through the substitution of clinker by pozzolan with a lower Mohs hardness and incorporation of WR.