Evaluation of the ultrasound test for estimating the depth of cracks in concrete

Abstract

The objective of this study is to evaluate the ultrasound test to estimate the depth of cracks in concrete, using a mathematical model published in the literature, and to verify this depth with more accurate results. Four concrete test specimens were molded for each proposed crack depth (5 cm, 10 cm, and 15 cm), simulated using zinc plates, placed during molding and removed before concrete hardening. The results show that the test is sensitive enough to detect the presence of the cracks in the concrete. The mathematical model used allowed for an estimation of the depths of most cracks, but the results are scattered and have a high margin of error for the depths of 5 cm and 15 cm. The cracks of 10-cm depth produced better results.

About the Possible Limitations in the Usage of the Non-Destructive Ultrasonic Pulse Velocity Method for Assessment of Cracks in Reinforced Concrete Structures, Subjected to Direct Environmental Exposure

“…The mechanical properties, the deformation characteristics, and the concrete parameters such as compressive strength and modulus of elasticity [3,6,7] can be determined from the velocity or transmitting time of the ultrasonic signal. The NDUPVM is used in order to verify the concrete homogeneity, to detect internal imperfections (presence of caverns, internal defects and cracks), to evaluate the depth of imperfections, to estimate the modulus of elasticity and the compressive strength of the concrete, and to monitor the characteristics variations of concrete throughout time [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][31][32][33][34][35][36][37][38][39][40][41].…”