钢绞线腐蚀后的部分预应力混凝土梁抗弯疲劳性能试验研究

对不同钢绞线腐蚀率下的部分预应力混凝土梁进行了静力和疲劳试验,通过分析开裂弯矩、跨中挠度、受拉区钢筋应变以及梁裂缝的发展规律,研究了钢绞线腐蚀率对部分预应力混凝土梁疲劳性能的影响。研究表明:钢绞线腐蚀会显著降低梁的疲劳寿命,是影响梁疲劳破坏形态的主要因素;腐蚀梁的挠度、应变和裂缝发展同样遵循无腐蚀梁的"三阶段"规律;在相同疲劳次数下,腐蚀率越大,受拉区非预应力钢筋的应变和梁的裂缝宽度越大,但梁跨中挠度受腐蚀率影响不显著。

Experimental research on fatigue behavior of prestressed concrete beams with corroded steel strands

The cracking-moment,midspan deflection,strain of steel in the tension region and the law of crack development were analyzed from the experiment of partly prestressed concrete beams,with different corrosion rates and under static and fatigue loads.On this basis,the effects,which corrosion rates of the steel strands have on the fatigue behavior,were studied.The results indicate that corrosion of steel strands,as a major factor to effect the failure mode of testing beams,can remarkably reduce the fatigue life of the beams.The deflection,strain and crack development of testing beams with corrosion,likewise,follow the regulation of "3-step" in the beams with non-corrosion.More the corrosion rate is,more the strain of normal steel in the tension region and the crack width of the beams are,with the same corrosion cycle,but the corrosion rate has a little influence on the midspan deflection.