Predicting the Compressive Strength of Concrete By Ultrasonic Pulse Velocity

The key resolution of non-destructive methods applied to concrete structures is to offer a suitable estimate of the quality of the material. One of the modern methods used in the test of concrete strength is the non-destructive testing applying the ultrasonic pulse velocity (UPV). In this study, the ultrasonic pulse velocity technique as non-destructive testing of concrete was used to distinguish concrete mixture design and show the predictive relationship between compressive strength and UPV. The effect of various grades of concrete (M15, M20, M25, M30, and M35) with water to cement ratio (w/c) of 0.45 and 0.5 were examined. It was observed that grade M15 cubes had the lowest transit time (37.6 – 41.2 µs) and grade M35 cubes had the highest transit time (48.7 – 49.9 µs) showing that the concrete with short transit time generates the highest pulse velocity than that with low transit time. Grade M15 cubes had the highest pulse velocity (3.6 – 4.0 km/s) and grade M35 cubes had the lowest pulse velocity (3.0 – 3.1 km/s). M15 cubes had the lowest actual compressive strength (18.1 – 19.3 N/mm2) and grade M35 cubes have the highest actual compressive strength (34.6 – 36.0 N/mm2). There was a good correlation between compressive strength and UPV. The study furthermore revealed that UPV can be used to accurately predict the compressive strength of concrete. For all concrete grades, the percentage variation did not exceed ± 2.5%.