An Experimental Study on Tensile Characteristic for CFRP Cable without Surface Treatments

Abstract

CFRP (Carbon Fiber Reinforced Polymer) cable can be advantageously used to overcome the problem of corrosion encountered in conventional PS steel strands. Since CFRP cable presents weakness against lateral pressure and stress concentration, the application of the anchorage system adopted for conventional PS steel strand is likely to fail in providing reliable resistance because of premature failure. Therefore, appropriate anchorage device needs to be developed for the anchoring of CFRP cable. The typical types of anchoring device for CFRP cable are wedge-type, bond-type and grip-type anchorages. Most of anchors are bond-type to measure the tensile property of CFRP cables. Generally CFRP materials like reinforcements, tendons, and cables have surface treatments to improve bond strength as sand coating, deformed shapes, fabricated covers and so on. In case of CFRP cable without surface treatment, its bond strength is much lower than CFRP cable with surface treatments. Accordingly, bond-type anchor may be long and tensile property of CFRP cable may be misestimated. In this study, tests for tensile property of CFRP cable without surface treatment have been performed. To improve the bond strength of CFRP cable, the end of the cable was split in order to widen bond area. The test results revealed that widening the end of CFRP improved the anchoring performance up to the ultimate strength of CFRP.