Effect of existing cracks in shear strengthening of concrete girders with external post-tensioning

Whittaker, Todd (2005) Effect of existing cracks in shear strengthening of concrete girders with external post-tensioning. [USQ Project]


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There is a need to strengthen bridges structures due to increased traffic loading and aging of bridges. Full bridge replacement poses the problems of high cost and disruption to traffic, so a suitable method or repair and strengthening are required.

External post-tensioning is considered as one of the effective methods of to strengthen bridge structures. A common deterioration of bridges is shear cracking. Existing shear cracks can limit the effectiveness of external post-tensioning.

Epoxy injection is a method of structurally repairing cracks. The injection of epoxy resin could possibly repair the shear cracks. This paper is utilizes the rehabilitation technique of strengthening with external post-tension and crack repair with epoxy injection.

The effect of the existing shear crack in an externally post tensioned reinforced concrete beam is a complex function depends on a number of parameters including the nature of the crack, concrete strength, prestressing force and amount of shear reinforcement. The amount of shear reinforcement could significantly affect the amount of stress transfer across an existing shear crack.

The repair strength achieved for reinforce concrete beams was shown to be influenced by the condition of the major diagonal crack after initial damage. This conclusion was
supported by surface-strain measurements, load deflection data and crack measurements.

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Item Type: USQ Project
Refereed: No
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Engineering and Surveying - Department of Agricultural, Civil and Environmental Engineering (Up to 30 Jun 2013)
Date Deposited: 27 Jun 2008 04:40
Last Modified: 02 Jul 2013 23:04
Uncontrolled Keywords: bridges, bridge structure, cracks, epoxy injection, external post-tensioning, flexural strengthening, rehabilitation, repair, shear strengthening
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090506 Structural Engineering
Fields of Research (2020): 40 ENGINEERING > 4005 Civil engineering > 400510 Structural engineering
URI: https://sear.unisq.edu.au/id/eprint/4242

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