Aiming at acknowledging the slaking of expansive red sandstones in Hongshanyao hydrojunction project

by using the scanning electron microscope

X-ray diffractometer and rock mechanics rigidity electroplating servo testing system(RMTS815.03) in the tests

three different weathering degree swelling sandstones with properties of slight swelling

softening and easily weathering are observed in the process of slaking and mechanics of slaking are analyzed. Finally the slaking of red sandstone is different from swelling and fissuring essentially. Experimental results indicate that: (1)The compressive strength of the moderate weathering red sandstone

when dried

is 5.85MPa

whereas is 0.2MPa when saturated. The rock self strength is decreased with the increasing of water content

which is in possession of the serious softening effect; (2)The slaking of the expansive rock is strengthened with the decreasing of cementation coefficient

which is irrelevant to the weathering degrees of red sandstone (the depth of embedding); (3)These studies are provided the theory guiding to settle the slope topsoil slip of Hongshanyao hydrojunction project and also could be used in other related domain.