A Fundamental Study on Anchor Performance of CFRP Tendons with Compressed Anchor Sleeve

Abstract

The anchoring of CFRP tendon can be performed by wedging, bonding or compressing. The wedge type anchor, used for PS steel tendon, is inappropriate for direct application to the CFRP tendon due to its low lateral stiffness. Since the bond performance of the CFRP tendon depends on the anchor performance, the bond type anchor presents the problem of requiring long steel sleeve in case of low bond performance or high tensile performance. Compared to the bond type anchor, the compressing type anchor offers better applicability but necessitates the development of a sleeve fitted to the dimensions of each CFRP tendon. This study intends to examine the anchoring characteristics of the compressed sleeve for the temporary anchorage of a CFRP tendon with diameter of 10 mm. To that goal, the properties of the 10 mm-diameter CFRP tendon were assessed using the bond type anchor and the corresponding anchor performance is compared to that of the compressed anchor. The test results revealed that the use of spacers in the compressed anchor provided lower anchor performance due to the characteristics of the spacers. For the specimen without spacer, the micro-deformations formed inside the sleeve were seen to compress the CFRP tendon by gearing directly the tendon and to provide anchor performance reaching about 72% of the tensile strength of the CFRP tendon. Further study shall develop a sleeve with increased compress force on the CFRP tendon so as to improve the anchor performance of the compressed sleeve. Moreover, solution shall also be provided to introduce a uniform compress force.