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为研究折线配筋先张预应力混凝土梁在疲劳荷载下的性能,设计制作2根跨度为7.5 m的折线先张梁,对其在不同上限和下限弯矩作用下进行疲劳受力性能和疲劳试验后的终静载试验。试验结果表明:整个试验过程中,混凝土应变仍基本符合平截面假定,剩余承载力不受加载历史影响,承载力和裂缝宽度仍可按GB 50010—2010《混凝土结构设计规范》推荐的算式计算,抗疲劳性能良好。对梁顶混凝土压应变、钢绞线、非预应力钢筋疲劳应力幅和疲劳应力比随荷载循环次数变化规律的算式进行拟合。
In order to study the performance of pre-stressed pre-stressed concrete beam with pre-tensioned prestressed concrete under fatigue load, two pre-tensioned prefabricated beams with a span of 7.5 m were designed and manufactured, and their fatigue behavior and fatigue under different upper and lower bending moments Final static load test after the test. The test results show that: during the whole experiment, the strain of concrete is still basically in line with the assumption of flat section and the remaining bearing capacity is unaffected by the loading history. The bearing capacity and the crack width can still be calculated according to the formula recommended in Code for Design of Concrete Structures of GB 50010-2010, Anti-fatigue performance is good. The fitting formulas of compressive strain of concrete beam, steel strand, fatigue stress amplitude of non-prestressed steel bar and fatigue stress ratio with the changing rule of load cycles were fitted.