Performance of alkali activated slag and pumice mortars against chloride ions penetration in the Persian Gulf

Considering the successful usage of alkali activated mortars in several countries and limited research on the durability of these materials, in this paper, permeability and durability of alkali activated slag and pumice mortar in chloride environments have been studied. In order to investigate the mechanical properties and permeability of alkali activated slag and pumice mortars tests such as workability, compressive strength, capillary water absorption, water absorption, chloride ion penetration in the Persian Gulf environment and mercury intrusion porosimetry have been conducted.The results show that the compressive strength of alkali activated slag mortar containing potassium hydroxide was slightly higher than the compressive strength of samples containing sodium hydroxide. In addition, the use of 10% pumice instead of slag has increased the compressive strength of alkali activated slag mortar. Also, the 91-day compressive strength of alkali activated mortars cured in the water was 48.4% higher than those cured in the air. In general, the diffusion coefficient of chloride ions in alkali activated slag mortars was lower than the diffusion coefficient of chloride ions in Portland cement mortar, which was due to less porosity in alkali activated slag mortars and the denser structure. Also, alkali activated mortars containing 90% of slag and 10% of pumice had the lowest diffusion coefficient of chloride ions and Portland cement mortar showed the highest one, which was well matched with the result of capillary water absorption coefficient.