Influence of cyclic wetting and drying using acid solution on mechanical properties of rock slope weathered sandstone / Muhammad Faris Qusyairi Hamat

A geotechnical structure need to consider the strength of rock mass structure to ensure its stability is adequate for sustainable structures. There are many type of strength parameters of rock mass structures that need to be justified before construction of tunnels, rock slope and underground subways. In tropical climates, mechanical properties of rock such as sandstone are influenced by the degree of weathering which affect overall strength capability of rock mass structures. Cyclic of wetting drying as a part of weathering process and this paper is devoted to the laboratory study of effect wetting drying cycles to the mechanical behavior of sandstone. Meanwhile, the Schmidt Rebound Hammer test is introduced to classify the weathering grade of the host rock sample. The sandstone samples were immersed in acid solutions with different cycles after 7, 14 and 28 days to undergo chemical reaction. The percentage of porosity was determined by the saturation and caliper techniques with the same specimen. Uniaxial Compressive strength test is a standard test used to evaluate the compression strength parameters. Other rock properties were obtained such P-wave velocity from Portable Ultrasonic Non-Destructive Test (PUNDIT) and density for the rock sample. In conclusion, as the degree of weathering and cyclic of wetting drying increases the porosity of the sandstone increases, p-wave velocity decreases. It was found that strength of sandstone decreases as the weathering degree and cycles increases since contact forces acting on the particle skeleton increases as the porosity increases