Load testing has considerable possibilities in bridges as regards their safety assessment. This paper presents a comparison study on the diagnostic and the proof load test supported by acoustic emission. Diagnostic load testing is based on the comparison of real bridge behaviour with analytical calculation. Proof load testing is based on incremental loading until the bridge materials approach their elastic limit, but never going beyond this point, to prevent the bridge from being damaged. Tests are compared in the case of a three-span concrete bridge, made of prestressed precast beams. In a diagnostic load, reaching accurate diagnosis was made possible by the calibration of the calculation model based on deflection measurements and by the definition of concrete (performance) parameters, mainly concrete tensile strength. In proof load testing, accurate assessment of the actual capacity was possible, thanks to the support of acoustic emission measurements.

Peer Reviewed