A Comparative Study between the Effect of Steel Fiber on Ultrasonic Pulse Velocity (UPV) in Light and Normal Weight Self-Compacting Concretes

Abstract

This research presents a comparative study to highlight the differences between the effect of using various contents of steel fibers on the ultrasonic pulse velocity (UPV) in two types of self-compacting concretes (SCC) which are identical in their constituent materials, the only difference between them is the coarse aggregate type (normal in one and light in the other) with various specimen lengths (200mm cylinders and 100mm cubes). In this work, six types of mixes were casted, the first three (Mix1, Mix2 and Mix3) are of normal-weight SCC having steel fiber content (Vf) : 0.0%, 0.4% and 0.8% respectively, and the other three (Mix4, Mix5 and Mix6) are of light-weight SCC with the same aforementioned steel fiber contents respectively. It turns out that, the ultrasonic pulse velocity is smaller in light-weight SCC than in normal-weight SCC, and the percentage of this reduction is higher in cylindrical samples than in cubic samples, and this percentage of reduction is reduced with the increasing in steel fiber contents. It also turns out that, the ultrasonic pulse velocity is increased with the increase in steel fiber contents, and this percentage of increase is higher in light-weight SCC than in normal-weight SCC, and it is also larger in cylindrical samples than in cubic samples. Moreover, when the specimen length has been focused on, it was found that, the ultrasonic pulse velocity is larger in (100mm) cubic specimens than in (100×200mm) cylindrical ones, and the percentage of this rise is also larger in light-weight SCC than in normal-weight SCC, and it is reduced with increasing steel fibers contents.