Damage detection in concrete members of berthing jetties is difficult to due difficulty to access the remote locations on the structure.  Using vibration based damage parameters for in-line structural health monitoring can not only save cost on inspection surveys but also help to provide warnings on structural degradation, accidents and overloads.  Damage plasticity model approach is used in this paper to develop non-linear damage model of reinforced cement concrete beams and test the sensitivity of natural frequency, mode shapes and modal curvature  to damages on concrete beams. Structural deterioration due to cracking tension, crushing in compression and the lowering of stiffness of the material has been included in a single model to analyze the damage detection capabilities of vibration based damage parameters. The paper describes how mode shape curvature can be used to identify location of damages with high accuracy.