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 testing

technique, has certain limitations and may yield different results due to factors related to

the internal structure of concrete. In this study, strength measurements were carried out

using the UPV method on concrete mixtures produced by considering several parameters

that are frequently varied in practice. For this purpose, concretes of different strength

classes 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, and

moisture). The maximum aggregate particle size (8 mm, 16 mm, and 22.4 mm) was also

defined 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 specimens

with dimensions of 15×15×15 cm³ at the age of 28 days. The results obtained from the

experiments indicated that the behavior of fresh concrete varied depending on the

concrete 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 class

increased, UPV values also increased. Likewise, as the maximum aggregate particle size

in the mixtures increased, UPV values were observed to increase depending on the

concrete strength class. For all three concrete strength classes, the highest UPV values

were obtained from specimens cured in water.