ABSTRACT
In a proof load test, the applied load is representative of the factored live load, to demonstrate experimentally that the bridge fulfils the code requirements. Signs of distress must be caught with the instrumentation by defining stop criteria. In the literature, several stop criteria for flexure are available. The German guidelines describe, amongst others, a limiting crack width and strain. However, the background of these limiting values is not clear. Therefore, a theoretical approach based on flexural theory is followed. The theoretically derived values are then compared to experimental results obtained from beam experiments. The result of this research work is a limiting value of crack widths and strains that can be used during proof load testing of concrete bridges. The arbitrary stop criteria that were used in the past can now be replaced by stop criteria that are based on the theory of concrete beams in flexure.
