engleski

Crack Repair Assessment by Ultrasonic Method

Cast in-situ concrete structures are hardly ever built under ideal conditions so defects may occur as the concrete is being cast or very soon afterwards. In most cases the cause of defects is inadequate design and poor workmanship. This paper describes the damage that occurred during the construction of a big shopping centre in Zagreb, Croatia. Very soon after the building construction was completed, large cracks appeared on the basement walls, and it was through those cracks that underground water permeated. Crack repair was done by injection of polymeric resins. During the wall repair a non-destructive quality control was done by ultrasonic method. The ultrasonic pulse velocity method is a method that involves measuring the travel time of ultrasonic pulse over the known path length. It makes it possible to take a great number of samples or make structure examinations without structure destruction. The assessment of repair successfulness is based on statistical analysis of the results of measurement results, that is to say, on Student’ s t-test. The results obtained showed that the ultrasonic method can be effectively used during the crack repair.

concrete structure; crack repair; injecting; ultrasonic testing

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