The Influence of Hydroxyethylmethyl Cellulose on the Heat Released during the Hydration of Modified Gypsum Materials

Abstract

This article presents the results of experimental research of modified gypsum materials. The primary aim of the research was to assess the influence of the hydroxyethylmethyl cellulose (HEMC) polymer on the heat of hydration of gypsum. In the study, the polymer was used as an additive in weight ranges from 1% to 3% in relation to pure gypsum. The water to gypsum ratio was at the level of 0.75. The heat of hydration of building materials is crucial, because it is one of many aspects that directly affects the binding time, therefore defining the potential applications of gypsum in the construction industry. It was shown that the addition of the polymer influences the value of the heat of hydration, and also extends the crystallization process. Based on the Avrami equation, two areas of the early and late stage crystallization of gypsum were observed. The obtained values of the kinetic parameter n of this equation indicate a different mechanism of crystal growth. With an increased content of the polymer, there was a decrease in the K parameter, which confirms that HEMC interferes with gypsum nucleation and crystallization.