Hydration Products that Provide Water-Repellency for Portland Cement-Based Waterproofing Compositions and Their Identification by Physical and Chemical Methods

The coatings formed by water-proofing compositions of a penetrating action are characterized by high physical and mechanical properties and good adhesion to the substrates used for their deposition. The experimental investigations of the influence multicomponent chemical additive that provide waterproofness on the formation of the hydration products of Portland cement have been carried out. The colmatation of the pores and capillaries by the hydration products of Portland cement with the complex chemical additive were simulated. Such pores were simulated by the formation of the cement-perlite mortar and the capillaries were simulated by the introduction of fiberglass to the cement paste. The data of X-ray phase analysis, infrared spectroscopy, and thermal analysis show the formation of carbonate and chloride AFm-phases and possibly the formation of the nitrate AFm-phase and calcite in the cement stone with the complex chemical additive. The data of electron microscopy research also showed that the hydration of Portland cement with complex chemical additive results in the formation of crystallohydrates that according to their morphological features can be identified as carbonate-, chloride-, and nitrate AFm-phases, portlandite, and calcite that grow on silicate surfaces with a negative surface charge.