Abstract: Now there is a 10 mm diameter monolithic CFRP tendon anchor without sleeve and it′s conical degree is 1∶10 in research group, the failure mode of the anchorage is the inner CFRP tendon cut off. This paper improved and redesigned the clamp anchorage for diameter 10 mm and 12 mm CFRP tendon. The improved anchorage set three conical degree and we cancel the cone angle difference between the anchor ring and the clip. The clip has two pieces, and the redesigned gap makes the clamp looked on the transverse section from the big diameter end to the small diameter end are six, eight and four pieces respectively. The influences of anchorage conical degree, pretightening force and thickness of aluminum sleeve on anchorage are analyzed through experiments. The results show that when the conic degree is 1∶15, the anchorage achieves the ideal failure of the external rupture on CFRP tendon, and the reduction of the conical degree can reduce the stress concentration on the inner CFRP tendon. The inner wall of the clamp handled as tooth pattern and the experiments adopt patterned aluminum sleeve can reduce the slippage of the anchorage. The experiment results show that large diameter anchorage is suitable for large thickness aluminum sleeve, and the smaller thickness sleeve is suitable for small diameter anchorage. The increase of pretightening force will reduce the slippage of each component of the anchorage, but it will not affect the ultimate tensile force of the anchorage.

Key words: CFRP tendon, clip anchorage, prestress, improved design, anchorage performance