Investigation the relationship between the variation in the zeta potential of portland cement depending on time and its setting behavior

In this work, the ZP measurements of portland cement in the presence of tap water, pure water, 5x10-3 M NaCl and 5x10-3 M CaCl2, as separately, as a function of time and the vicat tests of the portland cement pastes which were prepared at the same conditions were carried out. Consequently, the relationship between the setting behavior (especially the beginning of the setting) of the cement and its ZP variation depending on time were investigated. In addition, in each medium the ions released from the cement into the solution given above depending on time were analyzed and SEM and XRD analysis were performed on the samples which were obtained after the vicat tests. The most important result obtained from this study is that; the comments stated by Nagele and co-workers (Nagele, 1986; Nagele and Schneider 1989) is not operate always that is sudden changes in the ZP curve of cement depending on time indicates the first or end of setting of cement.