Development of a Non-Destructive Testing Technique for Identification of Prestress Force in Concrete Beams

• Main Authors: Hsing-Chih Wei, 魏星池
• Other Authors: 張國鎮
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/6k349e

碩士 === 國立臺灣大學 === 土木工程學研究所 === 105 === Facing the aged problem of bridges, it is necessary to administrate the full lifecycle of bridges. Prestressed bridges are widely applied in highway and railway. However, prestressed bridges encounter a variety of deteriorating reasons and affect the safety, like creep of concrete, relaxation of tendon…etc. This study uses magnification factor method to develop a non-destructive testing method to identify the prestress force in the concrete beams. Using the deflections to get the axial force. In this study, verifying the method by the experiments of 7m and 15m prestressed beams. The results show that the identifications are well under the II-order effect is significant. The results also show the applied concentrated force couldn’t be larger than one tenth of prestress. According the results of this study, it suggests the applied concentrated force shouldn’t be too large and the measured position is better at the position occurs the maximum deflection. For the prestressed beams with the straight tendon, it could get accuracy identifications under above conditions. For parabolic shape tendon case, it may be affected by some unknown reasons and need detail study in the future.