Title:
Strengthening of RC Beams with External Post-Tensioned CFRP Tendons
Author(s):
A. Elrefai, J. West, and K. Soudki
Publication:
Symposium Paper
Volume:
245
Issue:
Appears on pages(s):
123-142
Keywords:
external prestressing; flexure; FRP; overloading; post-tensioning; strengthening; tendon; unbonded
DOI:
10.14359/18766
Date:
4/1/2007
Abstract:
The monotonic flexural performance of reinforced concrete beams strengthened with external post-tensioned CFRP tendons was investigated. Variables include straight and double draped tendon profiles, and two post-tensioning conditions: at service load (50% of the yielding capacity - in-service beam) or after overloading to twice the steel reinforcement yield strain (overloaded beam). The beams were tested to failure in four-point bending. Experimental results indicated that the tendon profiles investigated did not affect the beam behavior. Overloading of the beam prior to post-tensioning had a significant effect on the deflection capacity of the beam, with a slight effect on the yield and ultimate capacities. A strain reduction approach, developed previously for unbonded steel tendons, was extended to model the beam behavior. The loading history of the beam prior to strengthening was explicitly accounted for in the model. The analytical predictions showed good agreement with the experimental values.