Nonlinear Characteristics of Damaged Concrete Structures under Vehicular Load

This paper investigates the possibility of using changes in the nonlinear characteristics of the reinforced concrete structures under vehicular loads to detect damage. An experimental study is carried out on a Tee-section reinforced concrete beam subject to the action of a moving model vehicle. Vertical accelerations and displacements are measured while the vehicle crosses the bridge. Nonlinearities are detected by examining the changes in the instantaneous frequency when the vehicular loads are at different locations along the beam. Results demonstrated that the large changes in the vibration behavior due to the damage could be amplified by the presence of vehicular load on top of the beam. A damage index, based on the flexural rigidity of the beam, is proposed which can be an indicator for the assessment of reinforced concrete bridge deck under vehicular load.