Estimation of compressive strength of self-compacted concrete with fibers consisting nano-SiO2 using ultrasonic pulse velocity

In this research the performance of ultrasonic pulse velocity in concrete is examined as a nondestructive experiment, in order to estimate compressive strength of fiber-reinforced self-compacted concrete with nano particles. For this purpose there were 40 mix plans including four groups of A, B, C and D in which cement was replaced with 0, 2, 4 and 6 vol.% of nano-SiO2 respectively. In this experiment a comparison was made between the four groups which included three types of fibers (steel: 0.2, 0.3 and 0.5 vol.%, polypropylene: 0.1, 0.15 and 0.2 vol.% and glass: 0.15, 0.2 and 0.3 vol.%). Cube specimens were tested in order to determine ultrasonic velocity. The compressive strength was also tested. According to the results, relations were established between ultrasonic velocity in the specimens and the compressive strength at different ages and so the range of the velocity of the waves was also determined for this kind of concrete.