For environmental conservation, resource saving and sustainable development, discarded concrete sources are introduced and current situation of its application is summarized. Then, the facing problems and solutions on concrete-recycling use are analyzed, and recycled application methods of discarded concrete are proposed.

To study the experimental method of axial compressive test of concrete columns in service strengthened with bonding FRP(fiber reinforced plastic), the post-tensioned pre-stressing method was employed to exert initial stress to the specimens before bonding FRP, Then FRP was bonded. Axial loading method of the specimens was that one main jack exerted axial force and two jacks provided stiffness for the specimens. In this way the complete stress-strain curves of specimens was obtained. The results indicated the technical target of axial compressive test of in service concrete columns strengthened with FRP was greatly achieved by using this experimental method.