CFRP吊索钢管混凝土拱桥长期受力性能试验研究

Test Study on the Long-Term Mechanical Behaviors of Concrete-Filled Steel Tube Arch Bridge with CFRP Suspended Cables

碳纤维（CFRD）筋具有优良的物理力学性能,可作为钢管混凝土系杆拱桥中的吊索。制作CFRP吊索钢管混凝土系杆拱桥模型,对其长期受力性能进行试验研究。试验结果表明：素混凝土的徐变系数较钢管混凝土大1.14倍,加膨胀剂混凝土的徐变系数较未加膨胀剂混凝土大10%;拱桥模型在273 d持续荷载作用下,系梁的预应力损失平均值为2.4%,CFRP吊索的拉力较初始值增加29.6%-48.5%,钢管拱的表面压应变较初始值增加203%-536%;长期挠曲变形与短期变形之比分别是钢管拱2.30-2.47,系梁1.96-1.40,桥面板1.81-1.50。

Carbon Fiber Reinforced Polymer （CFRP） tendons have excellent physical and mechanical performances, which can be used as suspended cables for concrete-filled steel tubular tied arch bridge. A concrete-filled steel tubular tied arch bridge model with CFRP suspended cables was made to study its longterm mechanical behaviors. Test results indicted that the creep coefficient of plain concrete is bigger than that of concrete-filled steel tube by 114%, the creep coefficient of concrete mixed with concrete expansion agent is bigger than that of concrete without concrete expansion agent by 10%. Shrinkage and creep effect of arch bridge under sustained load were tested for 273 days. Tested results indicate that the prestressing loss of tie-beam is 2.4%, the tension of CFRP suspended cables will increase 48. 5%-29.6% compared with initial value, and the surface pressure strain of steel-tube arch will increase 203%-536 % compared with initial value. The ratio of long-term deflection to short-term deflection is respectively 2. 30-2.47, 1.96-1.40, and 1.81-1.50 for steel-tube arch, tie-beam and the bridge deck.