Various nondestructive testing (NDT) techniques are available to evaluate the condition of existing concrete structures. These NDT techniques can help to determine in-situ load carrying capabilities and in turn be used to help develop a cost effective rehabilitation solution. In this project, the four pier caps of Denver Colorado’s Quebec Street Bridge over Air Lawn Road were inspected using several different NDT techniques. These tests included: carpenter hammer sounding, Schmidt hammer, and ultrasonic pulse velocity (UPV) testing including tomography. In addition visual testing was used to identify crack patterns and spalling conditions. Contour plotting of the NDT data was completed on individual and combined NDT techniques to better determine the condition of the piers. Equal weighted percentages were assumed in combining the hammer sounding, Schmidt, and direct ultrasonic transmission data. Although hammer sounding and Schmidt rebound techniques were used to determine the condition of the exterior layers of the piers, ultrasound and tomography were used to determine the condition of the interior. Various tomographic slices were completed between adjacent sides and from face to face. After the NDT tests were completed, the data were analyzed, interpreted and recommendations were given to further destructively examine local areas of the piers. Destructive tests included compressive strength, chloride, and petrographic testing. The specific detail of all testing methodologies used in this study will be discussed further along with the specific results for the northwest pier cap.
展开▼
