An Experimental Investigation on the Durability of Clay-Bearing Rocks in Different pH Conditions

Rocks containing clay minerals are the most important and applicable problematic weak rocks. Considering the critical role of these rocks in engineering projects, various test methods have been introduced for assessing their durability. In the current research, various tests were carried out on eight samples of clay-bearing rocks to evaluate their durability properties under different pH conditions. For this purpose, some of their mechanical and physical characteristics were measured. Next, three durability tests including the dynamic slake durability test (ID), static slaking test (Is), and jar slake test (R values) were performed. Three solutions with pH values of 3, 5, and 7 were prepared by sulfuric acid for studying the pH impact on the disintegration of the studied rocks. Eventually, the slake durability test was performed at the aforementioned pH levels for up to 10 cycles. Based on the obtained results, it was concluded that the durability index decreases upon decreasing the pH value. The rock samples used in this study exhibited a remarkable durability reduction of ~ 100% at pH of 3. Moreover, simple regression analysis results revealed a statistically significant relationship between ID, Is, and R value.