Flexural behavior of reinforced concrete beams strengthened with externally-bonded carbon fiber reinforced polymers

Title: Flexural behavior of reinforced concrete beams strengthened with externally-bonded carbon fiber reinforced polymers
Author(s): M. Reza Esfahani, M. Reza Kianoush, A. Reza Tajari
Paper category : conference
Book title: 2nd International RILEM Symposium on Advances in Concrete through Science and Engineering
Editor(s): J. Marchand, B. Bissonnette, R. Gagné, M. Jolin and F. Paradis
Print-ISBN: 2-35158-003-6
e-ISBN: 2351580028
Publisher: RILEM Publications SARL
Publication year: 2006
Nb references: 13
Language: English

Abstract: This paper investigates the flexural behavior of reinforced concrete beams strengthened by CFRP sheets. Twelve concrete beam specimens with the dimensions of 150 mm width, 200 mm height, and 2000 mm length were manufactured and tested. Reinforcing bars with three different ratios, ?? in beam sections were used as longitudinal tensile reinforcement in specimens. Nine specimens were strengthened in flexure by CFRP sheets. Other specimens were considered as control specimens. The width, length and number of layers of CFRP sheets varied in different specimens. In six specimens, the CFRP sheets were extended beyond the two supports to prevent failure due to debonding of CFRP sheets at its two ends. Therefore, the maximum effect of CFRP sheets on flexural strength can be evaluated. Similar to the previous studies, the flexural strength and stiffness of the strengthened beams increased compared to the control specimens. From the results of this study, it may be concluded that the provisions of ACI 440 Code and ISIS Canada overestimate the effect of CFRP sheets in increasing the flexural strength of beams with small reinforcing bar ratios. With increasing the reinforcing bar ratio in beams, the ratios of test load to the load calculated by ACI 440 Code and ISIS Canada, Ptest/PACI and Ptest/PISIS, increased. Therefore, the equations proposed by ACI 440 and ISIS Canada are more appropriate in beams with large reinforcing bar ratios. In the strengthened specimens with large reinforcing bar ratio, close to the maximum code value ?max, failure occurred with adequate ductility.

Keywords: flexural strengthening, FRP polymers, bar ratio, concrete beams

Online publication: 2006-08-02
Classification: 3.3 Theme 3: Monitoring, Repair and Maintenance of Concrete Structures
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2351580028.091