Chemical stability of basalt fiber in alkaline solution

The chemical stability of basalt fiber in alkaline solution is investigated by the means of weight retention and tensile strength retention. It has been observed that the basalt fiber immersed in weak alkaline solution is very stable whereas the basalt fiber immersed in strong alkaline solution shows poor weight retention due to the high dissociation constant. On the other hand, the tensile strength of basalt fiber in alkaline solutions is drastically decreased regardless of alkaline solution concentrations. Also basalt fiber in saturated Ca(OH)2 solution, which is similar to the alkaline environment of cement hydration, shows very low weight loss and high stability even after 3 months of immersion compared to glass fiber in the same condition.