【摘要】 为研究火灾高温后组合梁桥的基本材料力学性能与特征,共制作3片具有代表性的缩尺梁模型:简支T形梁、简支箱形梁及连续箱形梁,利用火灾试验炉进行局部三面受火试验,并给出详细的试验方案。通过受火后取样试件与未受火试件的材性试验结果对比,可以发现受火(最高温度在700~900℃)对钢板材料的屈服强度及极限强度均有一定程度的降低,降低幅度为10%~20%;而钢板材料弹性模量随温度升高略有变化,但变化值不大。火灾对混凝土强度材性的影响可以忽略不计,但对其冷却后的材料强度有一定影响,相对于常温混凝土其强度会降低5%左右。更多还原

【Abstract】 In order to investigate the basic mechanical performances of the composite girder under the fire loads,three typical experimental models including simple-support T-section girder,simple-support box-section girder,and continuous box-section girder,were built.After establishing a detailed experimental plan,a fire experiment loaded on three sides was conducted in a laboratory fire furnace.The comparative study on the material characteristics of steel between the models before and after the fire loads showed that the yield and limit strengths decreased by10%~20%after fire loads with the 700~900 ℃.The elastic modulus of the steel girder only slightly changed with the increase of temperature.The influence on the concrete material during the fire could be almost ignored;however,5%decrease of the concrete material strength could be found after cooling off.The results provided good experimental and theoretical foundation for determining the basic material characteristics in the anti-fire design of the composite girders.更多还原