Experimental Investigation on the Creep Property of Carbon Fiber Reinforced Polymer Tendons under High Stress Levels

Carbon fiber reinforced polymer (CFRP) tendons are generally used as prestressing members to take full advantage of their high strength. Their creep property is one of the key factors influencing the reliability and safety of the structures, especially under sustained high stress. In this study, using a new wedge-type anchorage system, experimental research was carried out on the creep behavior of CFRP tendons under high stress levels from 0.69 to 0.85 f(u). All the tests lasted for a duration of 1000 h. It was found that the creep coefficient tends to increase with the stress level. Compared to their static properties, the residual strength of CFRP tendons after creep tests is 4.54% lower while the after-creep elastic modulus is 6.99% higher. Through data analysis, a semi-logarithm linear relationship between the creep coefficient and time was established, and the creep coefficients at 1 million hours were extrapolated.