Utilization of the accelerated weathering test method for evaluating the durability of sedimentary rocks

The durability and geotechnical properties of 12 sedimentary rock samples collected from the Damghan area, Iran, were investigated. The rocks were subjected to mineralogical, physical, index and mechanical laboratory tests. Ten-cycle slake-durability tests were performed on the rocks using natural water and sulfuric acid solutions. The results of the mineralogical and X-ray diffraction studies indicated a change in the amount of soluble minerals after the slake-durability test in acidic solutions. A new test method, namely the accelerated weathering test (AWT), was conducted using a new apparatus designed and made for this purpose using natural and sulfuric acid solutions in ten wetting–drying cycles. Changes in the physical and index properties were observed in all tested samples after the fifth and tenth cycles of the test. A linear decrease in the values of the mechanical properties with decreasing pH of the solution and decreasing specimen size were observed in all samples under the test conditions. We present four new classification systems by which to classify the rocks after the AWT. Based on these results, the AWT can be used as a supplementary or even suitable independent test for evaluating the durability of rocks.