Three same size assembly precast beam with cast-in-place groove and one general integral beam were designed and made to test the shearing capacity of the groove.We investigated the mechanical parameters

such as bearing and deformation ability

and found the change law of local stiffness for the groove.The results show cast-in-place groove has little effect on bearing capacity of assembly precast beam and the deformation ability meets the design specification requirements.The position of maximum bending moment is bad for junction.The local stiffness of castin-place groove decreased fast at the beginning of loading.The integral rigidity was degraded into1/3finally.