PSI - Issue 52

Sairam Neridu et al. / Procedia Structural Integrity 52 (2024) 267–279 Sairam Neridu/ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 3. (a) Cracks in Pier wall; (b) Crack at 1/4 of height (c) Crack at mid-height; (d) Crack at 3/4 of height.

5. Experimental and Numerical Study 5.1. Non-Destructive Test (NDT)

The observation of vertical cracks in the pier wall of the bridge raises significant concerns over its structural integrity. In response, several site NDT tests were proposed to determine the extent and severity of the damage. The proposed tests include the Ultrasonic Pulse Velocity (UPV) test, as per IS:516 part 5 to measure the integrity of concrete and the depth of the cracks, the Rebound Hammer test, as per IS: 13311 part 2, to measure the surface hardness and predict the compressive strength of concrete, and semi-NDT test has been performed to know the exact compressive strength from extracted cores. The expected results of these tests provide a comprehensive assessment of the pier wall's structural integrity and inform a remedial plan to address identified issues. The UPV test is a non-destructive technique that uses ultrasonic waves to evaluate the concrete's quality and integrity. The velocity of the waves is influenced by the concrete's density and uniformity, and the results inform the concrete's quality for each pier member. Table 2 presents the results of the UPV test conducted on the pier wall, providing the corrected pulse velocity value for each member's concrete quality evaluation. The UPV test results indicate that the concrete quality of members 1, 2, and 3 is poor or doubtful, while members 4 and 5 have good concrete quality. The reasons for the poor quality of concrete due to improper mixing of the concrete can result in