New Approach towards Crack Determination in Concrete Using Upv Test

Nondestructive testing of concrete allows the inspection of larger areas of concrete members at lesser cost than coring and provides more information than visual inspection. This paper addresses a new approach for determining the positions and size of cracks in concrete members by using ultrasonic pulse velocity test. Three plain concrete beams, containing artificial cracks (30 – 60% of the beam thickness) created by placing a separator in the moulds before concrete casting, with different dimensions were prepared. Crack depth is conventionally determined by placing transducers on flat surface perpendicular to crack plane. The current approach described in this paper showed new test method that have further advantages; 1) validity to determine shape and size of inclined cracks as well, 2) feasibility of placing transducers not only on surface perpendicular to crack but also on any available surface of the structure near the crack, and 3) ability of determining cracks in structures having curved surfaces. The results showed that crack depth was identified with better accuracy compared to other conventional methods. Error in determining the crack depth by the new method was in the range of 0.16 – 6.89%.