The effect of pH of water and mineralogical properties on the slake durability of tuff in north Qazvin

Slake durability of rock is an important engineering parameter for evaluating deterioration rock in chemical and physical agents that related to mechanical properties rock. The main purpose of this study is to assess the influence of the number of drying and wetting cycles under variable pH conditions and controls of mineralogical composition on durability. For this purpose, five different types of tuff were selected from different parts in north Qazvin city. The samples were subjected to multiple-cycle slake durability testing with different pH values solution. Also the slake durability tests in saturated condition on samples, petrographical analyses and basic physical - mechanical test were performed. In addition, to assess the influence of mineralogical composition on durability, the mineral contents of the original material and the material passing from the drum of the slake durability apparatus after fifteen cycles were also determined by XRD analyses. It was concluded that the slake durability of tuff is independent of the pH in acidic solution circumstances. Mineralogical composition, fabric and weathering rate are considered to have a greater influence on the slake durability of tuff. A strong relationship between the point load strength and the fifteenth-cycle slake durability index is found in the rock types studied.