Influences of Cellulose Ether on Separation of Latex Modified Cement Paste by Still Standing Test

Cellulose Ether (CE) is often used in conjunction with latexes to modify the properties of cement based materials. In view of the lack of research on the properties of the fresh latex modified cement paste (LMCP) with CE, the influence of CE on the separation of LMCP was studied in this paper to understand better the application of these two kinds of polymer. The cement slurry was stratified by still standing test, appropriate amount of separated supernatant was dried to calculate the ratio of separated latex of LMCP. The results show that the ratio of latex separated from LMCP is not much affected when the dosage of CE is less than 0.3%; in principle, the ratio of separated latex decreases with the dosage of CE increasing; when keeping the polymer/cement ratio (P/C) constant and varying the W/C, the ratio of separated latex increases with the W/C increasing; when the dosage of CE is more than 0.3%, the W/C has a little effect on the ratio of separated latex of LMCP; when keeping the W/C constant, varying the P/C, the ratio of separated latex increases with the P/C increasing, the presence of 0.1% CE has not much effect on the ratio of separated latex, while the latex particles are almost completely remained in the cement paste when the dosage of CE is 0.5% no matter what the P/C is.