The uniaxial compression tests under dry and saturated states were carried out with sandstone, concrete and uni-body bi-material model for rock-concrete,in order to study the damage characteristics of uni-body bi-material model under dry and saturated states,and reveal the damage mechanism. The results show that uni-body bi-material model for rock-concrete exhibit a mechanical property of continuity of single medium model. The strength of uni-body bi-material model for rock-concrete is between rock and concrete,and more close to the concrete samples with lower strength. The failure modes of th...