Ultrasonic investigation on the effectiveness of crack repair in concrete

Investigação ultrassônica da eficácia do reparo de fissuras no concreto

abstract:

The crack injection technique using epoxy systems is usually performed in the services of rehabilitation of surface cracks in concrete structures. The evaluation of the injection process can be done by the removal of cores, which is a destructive test not able to evaluate the entire structure. Alternatively, the use of nondestructive testing, specifically those based on the propagation of stress waves can provide information on the effectiveness of injection services. Even though the time-of-flight technique which provides the ultrasonic pulse velocity is the most common parameter used in concrete evaluation, the ultrasound waveform energy-related parameters can be used to indicate if crack was fully filled. The energy of the ultrasound signal depends on the propagated travel path, which differs when the crack is not filled. This paper presents the results of an experimental program with artificial surface cracks filled with epoxy in different depth fractions. Two types of epoxy were used. It was observed that the ultrasound waveform energy-parameters were able to detect repair effectiveness.

Keywords:
ultrasound; nondestructive methods; energy related parameters; crack repair