| Title |
Flexural Strengthening of Full-scaled RC Beams with Externally Post-Tensioned CFRP(Carbon Fiber Reinforced Polymer) Strips |
| Authors |
You Young-Chan ; Choi Ki-Sun ; Kim Kueng-Hwan |
| Keywords |
CFRP Strip ; Externally Post-Tensioning ; Debonding Failure ; Rupture Strength |
| Abstract |
A full-scaled model test has been performed in order to investigate the behavior of RC beams strengthened with externally post-tensioned CFRP(Carbon Fiber Reinforced Polymer) system. At the same time, flexural strengthening test results obtained from a series of small-scaled RC beam with respect to many parameter in the previous studies were verified. A total of 4 specimens have been manufactured including unstrengthened control beam. The specimens strengthened with post-tensioned CFRP strips consist of bonded and unbonded systems with 2 different types of mechanical anchorages. The post-tensioning force of 50% of CFRP tensile strength which is considered optimum in the previous studies was applied. From the test results, it was found that all the specimens strengthened with post-tensioned CFRP strips finally failed by the rupture of CFRP strips regardless of post-tensioning system because the anchorage can clamps the CFRP strips up to its rupture strength. On the contrary, specimens strengthened with simply bonded CFRP strips showed debonding failure below 50% of CFRP tensile strength due to premature debonding. Also Increase in cracking load, yielding load and nominal strength were observed at the specimen strengthened with post-tensioned CFRP strips, resulting in improved strengthening performance. Therefore, the full strength of CFRP strips can be utilized in strengthening by introducing post-tensioning of 50% of its tensile strength. |