On-site assessment of bridges supported by acoustic emission

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 ReviewedPostprint (author's final draft

Some relevant experiences from proof load testing of concrete bridges

The paper presents the results and experiences derived from a series of proof load test on concrete bridge structures. There are three main parts of the paper. The first part is a theoretical part related to the assessment of the target values of the proof load tests. The load level in the test necessary to guarantee a predefined safety level under real traffic conditions can be obtained in a reliability-based methodology with two different approaches depending on if data is available or not for the bridge under evaluation. The second part is an evaluation of the measurements results during static loading. The important element is the correct and accurate estimation of the elastic and permanent values of measured quantities taking into account their speed of stabilization. The third part is connected with an incremental loading and is about estimation of the time when the bridge materials approach their elastic limit during incremental loading and therefore, the test should stop.Postprint (published version

On-site assessment of bridges supported by acoustic emission

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 Reviewe

Some relevant experiences from proof load testing of concrete bridges

The paper presents the results and experiences derived from a series of proof load test on concrete bridge structures. There are three main parts of the paper. The first part is a theoretical part related to the assessment of the target values of the proof load tests. The load level in the test necessary to guarantee a predefined safety level under real traffic conditions can be obtained in a reliability-based methodology with two different approaches depending on if data is available or not for the bridge under evaluation. The second part is an evaluation of the measurements results during static loading. The important element is the correct and accurate estimation of the elastic and permanent values of measured quantities taking into account their speed of stabilization. The third part is connected with an incremental loading and is about estimation of the time when the bridge materials approach their elastic limit during incremental loading and therefore, the test should stop