Paper Title
Laboratory Simulation of Erosion Process for Three Thai Sandstones

Abstract
This study aims at simulating rock erosion by slake durability testing under wet and dry conditions. Phra Wihan sandstone and conglomeratic and bedded sandstones from Phu Phan formation are used as rock specimens. The test parameters are modified from the standard to accelerate the erosion process, where 2,000 drum revolutions are used for up to 80 test cycles. Results indicate that fragment roundness and sphericity increase with test cycles. Bedding planes reduce the roundness of bedded sandstone as the fragments become smaller. Phra Wihan sandstone is physically insensitive to water. Scrubbing and colliding processes mainly reduce the fragment sizes, under dry condition. Under submerging condition, even though fragment weight is decreased by its buoyancy force, intergranular bonding of the two Phu Phan sandstones is weakened by water penetration, leading to higher percentage of passing materials. Keywords - Slake Durability, Roundness, Sphericity, Intergranular Bonding