The Effect of Additives Regulating the Setting Time on the Resistance of Chloromagnesial Composites to Cracking During Prolonged Water Saturation

The resistance of chloromagnesial composites to prolonged water saturation is determined by the softening coefficient and the tendency to cracking. Technological methods for preventing the cracking of a magnesia binder stone in contact with water have a number of disadvantages, in particular, related to their difficult reproducibility in production conditions. This study is devoted to the search for additives that make it possible to regulate the processes of structure formation of chloro-magnesial composites in order to form predominantly stable phases evenly distributed in volume during prolonged saturation with water. In the course of the work, standard methods were used to study the properties of dough and astringent stone, as well as microcalorimetry. As a result, it was found that the addition of sodium tripolyphosphate significantly slows down the setting time of the chloromagnesial composition, but eliminates the tendency of the artificial stone obtained from it to crack during prolonged water saturation.