Creep behavior enhancement of a basalt fiber-reinforced polymer tendon

Creep behavior is a key factor controlling the long-term behavior of basalt fiber-reinforced polymer (BFRP) tendons when employed as prestressing members. This paper studies the creep behavior of pretension-treated BFRP tendons and evaluates its potentials in prestressing applications. Based on an effective enhancement by pretension, the evaluation of the creep behavior of pretension-treated BFRP tendons was conducted. The parameters comprise the creep strain-time relationship, creep strain rates, residual strength and elastic modulus after creep and the prediction of the creep rupture stress based on a reliability analysis. In addition, the creep behavior of pretension-treated BFRP was also compared with the results of original untreated BFRP tendons. The results show that pretension-treated BFRP tendons can sustain a stress level of 0.7 fu without fracture within 1000 h, 17% higher than the untreated BFRP tendons (0.6 fu). The creep strain rates of BFRP tendons after pretension exhibit a substantially low level in comparison to those without the pretension process, demonstrating the effectiveness of the pretension on creep strain rate control. The one million-hour creep rupture stress of BFRP tendons is effectively enhanced from the original 0.59 fu to 0.63 fu based on experimental fitting and from 0.52 fu to 0.54 fu according to a reliability analysis.