PSI - Issue 64

Alexander Shuvalov et al. / Procedia Structural Integrity 64 (2024) 445–455 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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The investigated columns are of square cross-section with dimensions of 1000×1000 mm and height of 7.5 meters. The main longitudinal reinforcement consists of 32 steel bars of reinforcement Ø32 mm of class A500C with a bar spacing of 100 mm. The transverse reinforcement is also made of smooth profile Ø10 mm steel bars of grade A240 with a spacing of 100 mm and 200 mm. The concrete cover thickness is 64 mm according to the design documentation. Before the start of the survey work, a programme of works was developed and agreed upon by several authorities. According to the developed programme of works, the points were located between the longitudinal and transverse reinforcement bars. Ultrasonic tests were performed on mutually perpendicular planes on pre-distributed sections of the structure. On each section the tests were performed on 15 points, distributed evenly throughout the investigated section. As a result, the total number of measurements amounted to approximately two thousand. The location of longitudinal and transverse reinforcement was marked prior to the investigations to eliminate the influence of steel elements within the concrete on the results of the investigations. The scheme of through ultrasonic sounding of columns is shown on Figure 4. Site visualizations and field photos are presented in Figure 5. A lot of preparatory work was done before the start of ultrasonic through sounding. • scaffolding was assembled with access to the surveyed columns on several levels; • the marking of points on the surface of the columns along the entire height was performed. The points were selected in the areas of absence of longitudinal and transverse reinforcement; • The leveling of the sounding points on opposite planes of the structure was performed; • To speed up the work, lubricant was applied to the sounding points in advance; • Areas with loose concrete were additionally grinded.

Fig. 6. Schematic of test locations