中文摘要：

进行7个火灾后型钢混凝土梁力学性能试验,考察剪跨比、受火时间对构件破坏形态、截面应变分布、变形性能、剩余承载能力的影响。试验结果表明,火灾后型钢混凝土梁在荷载作用下的破坏形态与常温下基本相同,但是经历火灾高温作用后,型钢混凝土梁出现腹剪斜裂缝的时间提前。火灾作用后发生弯曲破坏的梁,加载初期沿截面高度的应变满足直线分布,应变分布符合平截面假定;大约80%极限荷载后,受到受压区混凝土开裂和型钢受压翼缘与混凝土之间相对滑移的影响,截面受压边缘混凝土的应变增长减缓,截面应变分布偏离直线,平截面假定不完全成立。火灾后型钢混凝土梁的荷载-跨中挠度曲线在试件屈服后都有一段不小的水平段,表明型钢混凝土梁在经历火灾作用后仍具有良好的后期变形能力;同时随着剪跨比的增大,后期变形能力增强。型钢混凝土梁经历火灾高温以后,其承载能力均有不同程度降低,试验结果和我国JGJ 138—2001《型钢混凝土组合结构技术规程》计算结果的对比表明,在本次试验中,梁斜截面抗剪承载力的降低程度在10%～21%之间,正截面抗弯承载力降低程度在16%～19%之间。

英文摘要：

Seven groups of test data are provided pertaining to the mechanical properties of steel reinforced concrete（SRC） beams after exposure to fire.Shear span ratio and time in fire are taken into consideration as the major parameters.The failure patterns and strain distribution along the height of specimen cross-section as well as the load vs.deflection curves and residual load bearing capacity of the specimens are obtained.Test results indicate that the failure mode of SRC beam after exposure to fire under load is similar to that in room temperature,but the web-shear cracks of SRC beam appear earlier.In the stage of initial loading,the stain along the section height of the beams with bending-damage is linearly distributed.But under about eighty percent of ultimate load,with the effect of concrete cracking at the compression area and relative slip between steel compressed flange and concrete,the stain of concrete at the compression edge of the section increases more slowly,and the section stain distribution is far from linear.The load vs.mid-span deflection curve of all specimens have a long horizontal section after yielding,which show that SRC beam after fire have good deformation capacity after the ultimate load.According to the experimental data and calculation results by JGJ specification,the diagonal shear strength of the specimens after fire reduce from 10% to 21%,and bending capacity of cross section from 16% to 19%,comparing with that in room temperature.