Durability of geopolymeric mortars based on recommended slag and kaolin percentages containing polymer

Geopolymers as a cementless concrete has attracted the attention of many researchers in recent years. In the construction of this type of concrete, instead of cement, various materials such as microsilica, metakaolin, zeolite, etc. are used. It is necessary to use chemical solutions to complete the geopolymerization process to form the adhesive. The present study examines the durability of geopolymeric mortars based on blast furnace slag (GGBFS) and replacement with percentages of kaolin in several molar amounts. In this research, GGBFS was used as a substitute for cement, and sodium hydroxide solution (SOD) with a concentration of 4 and 8 M and sodium silicate (glass water) were used as chemical solutions. The basic materials were examined individually and in combination with other components of the mixture. For this purpose, kaolin ceramic powder was mixed in 50% and 75% with the GGBFS, which a total of 12 mixing plans were made. The characteristics studied are: compressive strength, penetration of chlorine ions in concrete (RCMT), electrical resistance, water absorption percentage, loss of compressive strength and weight loss after exposure to sulfuric acid solution. From the study the following results were obtained: the use of kaolin powder and slag reduces the compressive strength in BSC4-50 (33%). However, the results of the presence of chlorine ions in concrete and the weight loss of mortar samples in sulfuric acid solution indicate that the use of kaolin powder and slag increases the durability of concrete samples under chloride attack conditions and reduces permeability in BSC8-50 (38%).