Application of the Non-destructive Methods to the Determination of Discontinuities Between the Bridge Steel Box Girder and Concrete

Abstract

AbstractAssessment of the condition of building structures is carried out for the purpose of maintenance planning, for old and damaged structures or for new structures assessment in case of doubt about the quality of performed works. When assessing the condition of building structures, priority must have non-destructive testing methods. So, it is necessary to apply, effective and accurate non-destructive methods for finding and characterization of different types of damages. This paper presents an innovative application of the impact-echo method to the specific problem of determining the discontinuity between the steel plate and concrete. Namely, during concrete pouring in the steel box girder of the bridge, there was a suspicion that there were discontinuities between the steel structure and the installed concrete because the concreting took too long and shrinkage of concrete was not tested. Several non - destructive methods were considered, between which ultrasonic wave reflection and impact-echo methods were selected as potential candidates. These two methods are commonly used for the determination of the thickness of structural elements and searching for delaminations, cavities, inhomogeneities, interruptions of concreting, etc., but a review of the literature did not find their application to our problem. Although the ultrasonic wave reflection method did not give good results, but by the impact-echo method, discontinuities and places of reduced adhesion of concrete to the steel structure was successfully determined.KeywordsBridge assessmentNon-destructive testingImpact-echo