Detection of delamination in concrete using ultrasonic pulse velocity test

An experimental study was performed to evaluate the delamination in the concrete using ultrasonic pulse velocity (UPV) method. Two slab specimens of 150-mm and 300-mm thicknesses consisted of delaminations of varying sizes at quarter depths. Using indirect transmission method, the transit times of longitudinal and Rayleigh waves were measured to determine the dynamic Young’s modulus and Poisson’s ratio of the concrete. The static modulus was also measured and compared.The location and size of the delaminations in the slab were evaluated from the direct transmission method. The diffraction of the longitudinal wave at delaminations decreased the wave velocity and a qualitative correlation was established between the transit time of the UPV signal and the size of the delamination.

► UPV test was done to determine the delamination in concrete slabs.
► Indirect transmission method allowed the determination of in situ concrete properties.
► The results from indirect and direct transmission test were consistent.
► The P-wave transit time correlate qualitatively with the size of the delamination.