Detection of Concrete Surface Crack Depth Using Ultrasonic Pulse Velocity (UPV) Methods

Abstract

AbstractSurface cracks are one of the most commonly observed distresses in concrete structures. Even though the crack depth is an important parameter to evaluate the depth of degradation and section capacity, only crack length and width are commonly documented. The typical ultrasonic pulse velocity (UPV)-based test setup available for crack depth measurement uses compression waves and two transducers, as a transmitter and a receiver. Since the crack depth measurement uses an indirect mode of transmission and requires a good coupling with the concrete surface, the implementation of this system is challenging. In this study, the feasibility of using a commercially available ultrasonic tomography equipment with an array of dry-point-contact shear wave transducers to estimate the depth of concrete surface opening cracks was evaluated under laboratory conditions. UPV data was collected on three concrete slab specimens with known notch depths using different transducer arrangements. The data was processed to identify the impact of notch depth and the transducer combinations on the notch depth calculation. Later, the depth of longitudinal cracks in two prestressed concrete girders was evaluated using the same ultrasonic tomography equipment. The results are promising and require further studies to develop guidelines to effectively use this technique for assessing crack depth in various components.KeywordsCrack depthLongitudinal wavesMulti-array transducersShear wavesTomographyUltrasonic pulse velocity