Effect of Concrete Strength Class, Maximum Aggregate Particle Size, and Curing Type on Ultrasonic Pulse Velocity

The Ultrasonic Pulse Velocity (UPV) method, although being a non-destructive testingtechnique, has certain limitations and may yield different results due to factors related tothe internal structure of concrete. In this study, strength measurements were carried outusing the UPV method on concrete mixtures produced by considering several parametersthat are frequently varied in practice. For this purpose, concretes of different strengthclasses were produced by varying the water/cement ratio (W/C) and cement content (C),and these concretes were cured under different curing conditions (water, air, andmoisture). The maximum aggregate particle size (8 mm, 16 mm, and 22.4 mm) was alsodefined as a parameter in the study. Fresh concrete tests included air content, unit weight,and slump tests. Hardened concrete tests were conducted on a total of 54 cube specimenswith dimensions of 15×15×15 cm³ at the age of 28 days. The results obtained from theexperiments indicated that the behavior of fresh concrete varied depending on theconcrete strength class achieved by changing the water/cement ratio and cement dosage,as well as on the maximum aggregate particle size. As the concrete strength classincreased, UPV values also increased. Likewise, as the maximum aggregate particle sizein the mixtures increased, UPV values were observed to increase depending on theconcrete strength class. For all three concrete strength classes, the highest UPV valueswere obtained from specimens cured in water.