Concrete bridge deck delamination detection by integrated ultrasonic methods

Accurate assessment of the quality of concrete bridge decks and identification of corrosion induced delamination leads to economic management of bridge decks. Ultrasonic methods implemented in various forms of integrated ultrasonic seismic devices, such as the Portable Seismic Pavement Analyzer (PSPA), can be successfully used for such purposes. Of special interest are three techniques: ultrasonic body-wave (UBW), ultrasonic surface-wave (USW) and impact echo (IE). While the first two are used in concrete characterisation, the IE method is the primary tool in delamination detection. The primary advantage the IE method has over the current practice of chain dragging is that it allows detection of delamination zones at various stages of deterioration: from initial to progressed and developed. This is also demonstrated by finite element simulations of two probable scenarios of delamination progression. Supported by advanced three-dimensional visualisation techniques, the PSPA can be described as a bridge deck sonar device.