Concrete overlays on bridge decks are thought to be more durable when comparing with the more common solution with asphalt. Of interest is to evaluate the concrete overlay regarding traffic and shrinkage/temperature induced stresses. In a pilot study nondestructive test systems were evaluated with focus on detecting hidden defects, (e.g. debonding), that may have induced identified surface cracks. Furthermore, calibration of material parameters for a similar composite slab was done using finite element technique and compared with experimental studies in laboratory. Good agreement was found between numerical and experimental results. This will serve as an input for future bridge FE-models.

Concrete overlays on bridge decks are thought to be more durable when comparing with the more common solution with asphalt. Of interest is to evaluate the concrete overlay regarding traffic and shrinkage/temperature induced stresses. In a pilot study nondestructive test systems were evaluated with focus on detecting hidden defects, (e.g. debonding), that may have induced identified surface cracks. Furthermore, calibration of material parameters for a similar composite slab was done using finite element technique and compared with experimental studies in laboratory. Good agreement was found between numerical and experimental results. This will serve as an input for future bridge FE-models.

Concrete overlays on bridge decks are expected to be more durable as compared with the more common asphalt solution. Besides stresses due to traffic load and temperature variations at service, the overlays are exposed to stresses due to long term shrinkage. Of interest is to evaluate the concrete overlay due to the shrinkage induced stresses at the composite interface. Three strategies have been employed to gain knowledge on the stresses; 1) use of non-destructive test systems via field observations, 2) a numerical study on a concrete composite slab tested in laboratory, 3) recordings of realistic shrinkage and climate data on a reference bridge using vibrating strain gauges and humidity probes in the newly cast concrete overlay. The data were used as input data for a linear elastic finite element model. This article demonstrates this last phase of the work.