Experimental investigation on the fatigue performance of multi-tendon basalt fiber reinforced polymer cable

Abstract

The fatigue performance of fourteen basalt fiber reinforced polymer (BFRP) cables, each containing 37 tendons with a diameter of 4 mm, was investigated. Four testing schemes were employed to examine the failure mechanism and factors affecting fatigue behavior, including manufacturing technology, tendon surface shape, and anchoring method. The findings suggested that the fatigue life of the cable was controlled by the tendon surface shape, and subsequently affected by both anchoring method and manufacturing technology. The pretension method can eliminate the wedge action of the load transfer component (LTC). The splitting failure of ribbed tendons usually initiated from transverse cracking of resin matrix and eventually leaded to continuous interface debonding. Interlayer splitting in tendons can be avoided by adjusting the outer fiber from bending to flattening, which improves the tensile stiffness of the cable with round tendons under cycle load. The cable can achieve 2 million cycles while maintaining a stable deformation state, which is achieved by using round tendons in combination with a variable-stiffness LTC composed of epoxy resin and glass microfibers. The variable-stiffness LTC effectively alleviated stress concentration at the loading-end cable. The static anchoring efficiency of the cable with round tendons reached 110% after undergoing 2 million cycles.