Abstract: Concrete cracks are commonly found in the aqueduct construction projects due to various adverse factors, such as, difference in loading conditions, temperature change, shrinkage of materials, rusty of steel reinforcement bars, swell induced by frozen and poor construction quality, etc. For cracks occurred at the concrete surface, the conventional mitigation methods are: applying an organic paint cover, patching at surface or grouting at the cracks. The ultrasonic level testing is usually used to compare the sonic velocity changes before and after the treatment. The accurate measurement of the sonic velocity changes before and after concrete surface treatment is important for the effectiveness of the cracking mitigation work. The common ultrasonic testing are: level testing, side testing and borehole sonic testing. This paper presents a case history of ultrasonic level testing application in the concrete cracking checking in an aqueduct construction project.

Key words: concrete structures, cracking in concrete, level testing, cracking treatment, aqueduct projects