Analysis of deformation failure characteristics of concrete wrapped sandstone composite structures

It is an effective remediation to use concrete package for unstable pillar in mining works. There have been few researches about rock's composite structure wrapped by concrete at home and abroad. Its deformation failure characteristic is analyzed by uniaxial compressive strength test of concrete wrapping sandstone composite structure. It is shown that on the condition of uniaxial loading, the composite structure's failure mode is mainly "X" progressive type and its cracks are mainly "X" type throughout inclusions. The ultimate load and residual strength of the sandstone wrapped by concrete are improved significantly. Under the condition of uniaxial loading, the mechanical behavior of concrete wrapping sandstone composite structure is studied from the aspect of energy. During the deformation failure progress of concrete wrapping sandstone without concrete wrapping sandstone, the relation between energy absorption and ultimate load is analyzed. It is illustrated that it has great contribution to the improvement of pillar's ultimate load by using concrete wrapping from the aspect of energy.