Rebound hammer tests are generally preferred as a non-destructive testing method as compared to destructive testing methods such as compression tests. In this study, a general series of rebound hammer tests and destructive tests were carried on in a heavy concrete laboratory. A set of concrete cubes measuring 100 x 100 x 100 mm were cast and subjected to water curing for 7, 14 and 28 days to obtain the cube strength and rebound number. Three grades of concrete, namely M20, M25 and M30 were used in this experiment. At 28 days, the minimum target strength should be 30 MPa. The rebound hammer tests were conducted before the compression tests. The data obtained for each test was evaluated and tabulated in the findings of this study. It was found that the variation between predicted strength and experimental strength for the rebound hammer test was 0.18%. This indicates that the rebound hammer test is able to predict strength with acceptable accuracy.

No abstract

Ultrasonic pulse velocity methods is one of the non-destructive testing methods. Commonly the compression test was used to determine the compression strength of concrete. Laboratory works had been carried out at heavy concrete laboratory to obtain the result for both non-destructive and destructive test. By using concrete cubes of sizes 100 x 100 x 100 mm and subjected to water curing for 7, 14, 21 and 28 days to obtained desire result for Ultrasonic Pulse Velocity and Compression test. Ultrasonic Pulse Velocity were initially done before the Compression test. The data obtained from each test has been evaluated and tabulated in this report. From this research, the variation between predicted strength and experimental strength for Ultrasonic Pulse Velocity testing was identified; the higher the pulse velocity, the higher the predicted strength and lower times passes by pulse velocity, the higher the predicted strength.