Studies of Ultrasonic Pulse Velocity Test on Concrete

Abstract

Ultrasonic Pulse Velocity Test is one of the best known techniques which is used for the measurement of concrete uniformity, its elastic modulus, layer thickness and presence of honeycombing in concrete.Three methods are adopted i.e. direct, indirect & semidirect method For Ultrasonic pulse velocity testing on concrete in present investigation. The aggregates used in concrete as a fine aggregate are river sand which is locally available. The coarse aggregates which are used in concrete making are of size 10 mm and 20 mm, respectively. Sieve analysis and specific gravity tests are performed for the aggregates. Concrete mix design is done for different concrete grades such as M20, M25, M30, and M40. Standard cube size of 150X150X150 mm has been used of concrete grade M25 and mortar 1:6. For the study of variation in age of concrete on UPV results. UPV results has been taken at the age of 7,28 and 56 days by direct and semi-direct method. Scatter plot has been plotted for UPV results of concrete and mortar cube versus age of concrete by direct and semi-direct method. Beams size 150x150x700 mm have been casted for variation in UPV results on different path length. UPV test results have been evaluated on M25 grade concrete beam at the age of 28 days by indirect method. Path length for indirect method on beam specimen is 600mm, 450mm, 300mm, and 150mm. Scatter plot has been plotted for UPV test results of concrete beam versus different probe interval by indirect method. Effect of different obstruction along path length can be evaluated by casting and testing of M25 grade concrete beams with different five obstructions. For that UPV test has been done on all five obstructions namely, hole at center of the beam, hole filled with water in beam, rubber mixed with concrete, bio-degradable material mixed with concrete, rebar placed in the beam. Indirect method is used for all m25 grade concrete at the age of 28 days. Scattered with smooth line plot has been plotted for comparisons of UPV results versus different probe interval with different obstructions at the age of 28 days. Variation in concrete grade and modulus of elasticity on UPV Results can be evaluated by casting of cylinders(300X150 mm) of M20, M30 and M40 grade concrete. UPV test has been done at the age of 7 and 28 days of casting by direct method. 300 mm path length is to be considered for direct method. Modulus of elasticity has been found by secant modulus method. Relation between UPV results and modulus of elasticity has been plotted. The aim of the investigation is to scrutinize the performance of concrete with increase in age. In indirect method, the effect of the distance between transmitting and receiving transducers are studied. Effect of different obstructions on UPV results are studied. Effect of concrete grade and modulus of elasticity on UPV results are evaluated.