Relationship between Ultrasonic Pulse Velocity Test Result and Concrete Cube Strength

This paper presents the findings of a study on the relationship between Ultrasonic Pulse Velocity (UPV) and Concrete Cube Strength; in three distinct stages. First, a preliminary investigation of the various properties of the materials used for the production of concrete was undertaken. This was followed by trial mix using a nominal mix of 1:2:4, water – cement, W/C, ratios of 0.4, 0.5 and 0.6; along with two different consolidation methods – manual and machine vibrated. Based on the result of trial mix, W/C ratio of 0.5 was used to prepare and cure 150mm x 150mm x 150mm concrete cubes. The third stage subjected the samples to UPV and destructive tests at the end of the following curing days: 1, 3, 7, 14, 21, 28, 56 and 90 days. Ultrasonic Pulse Velocity test result showed an inverse relationship (of -0.935) with the crushed concrete compressive strength. Correlation test, multiple regression analysis, graphs and visual inspection were used to analyze the results. The conclusion drawn is that there exists a relationship between UPV test results and compressive strength. It is expressed as follows: y = 151- 3.2x1; where y and x1 are compressive strength and UPV test results respectively. Hence it is recommended that the above formula can be used in converting the UPV test results to compressive strength