The Effect of Alkaline Solution-to-Slag Ratio on Permeability of Alkali Activated Slag Concrete

This study investigated the effect of alkaline solution-to-slag ratio on permeability of Alkali-Activated Slag Concrete (AASC). Concrete, as the most widely used building material, has an undeniably important role in development of economic and civic infrastructure. Alkali activated slag cement is an environmentally friendly alternative to Portland cement, which can be produced by using an alkaline solution to activate the binding effect of the blast furnace slag. Permeability of concrete has a direct impact on its durability, so in this study a series of tests were arranged to examine the effect of alkaline solution-to-slag ratio on water impermeability, chloride permeability, short-term and total water absorption and compressive strength of AASC specimens. In experimental study four concrete mixes with alkaline solution-to-slag ratios of 0.4, 0.45, 0.50, and 0.55 were considered. One mix made by ordinary Portland cement were also considered for comparison of results. In addition, The images taken from samples AASC and Ordinary Portland Cement Concrete (OPCC) by means of scanning electron microscopy (SEM) were used to study the comparison of microstructure. The results showed that the alkaline solution/slag ratios of 0.45 and 0.50 are the optimum values for AASC production from the durability and permeability point of view.