刘桥, 韩重庆, 许清风. 高强钢筋混凝土连续T形梁受火后抗弯性能试验研究与数值分析[J]. 工程力学, 2015, 32(12): 179-187. DOI: 10.6052/j.issn.1000-4750.2014.04.0298
引用本文: 刘桥, 韩重庆, 许清风. 高强钢筋混凝土连续T形梁受火后抗弯性能试验研究与数值分析[J]. 工程力学, 2015, 32(12): 179-187. DOI: 10.6052/j.issn.1000-4750.2014.04.0298
LIU Qiao, HAN Chong-qing, XU Qing-feng. EXPERIMENTAL RESEARCH AND NUMERICAL ANALYSIS OF THE FLEXURAL BEHAVIOR OF RC CONTINUOUS T-BEAM WITH HIGH-STRENGTH BAR AFTER FIRE[J]. Engineering Mechanics, 2015, 32(12): 179-187. DOI: 10.6052/j.issn.1000-4750.2014.04.0298
Citation: LIU Qiao, HAN Chong-qing, XU Qing-feng. EXPERIMENTAL RESEARCH AND NUMERICAL ANALYSIS OF THE FLEXURAL BEHAVIOR OF RC CONTINUOUS T-BEAM WITH HIGH-STRENGTH BAR AFTER FIRE[J]. Engineering Mechanics, 2015, 32(12): 179-187. DOI: 10.6052/j.issn.1000-4750.2014.04.0298

高强钢筋混凝土连续T形梁受火后抗弯性能试验研究与数值分析

EXPERIMENTAL RESEARCH AND NUMERICAL ANALYSIS OF THE FLEXURAL BEHAVIOR OF RC CONTINUOUS T-BEAM WITH HIGH-STRENGTH BAR AFTER FIRE

  • 摘要: 进行了高强钢筋混凝土连续T形梁常温下和受火后的抗弯性能对比试验研究。2根对比试件进行常温下静载试验,3试件分别按照ISO 834升温曲线受火30 min、60 min和90 min,并自然冷却至室温后再进行静载试验。研究了升降温过程中截面温度场变化规律和试验梁的破坏形态,得出了受火后高强钢筋混凝土连续梁的弯曲刚度、延性系数、屈服荷载和极限荷载的劣化规律,并与常温对比试件的试验结果进行了对比分析。研究表明:在升温段,连续梁截面温度场呈现外部温度高内部温度低的层状分布规律;在降温段,温度场呈现外部温度低内部温度高的圈状分布规律。随着受火时间增加,受火后连续梁的屈服荷载和极限荷载均呈抛物线型下降;火灾后连续梁弯曲刚度显著降低,其下降程度明显大于屈服荷载和极限荷载的下降程度;受火后连续梁的延性系数也明显降低。有限元模拟分析得到的升降温截面温度场和火灾后抗弯性能结果均与试验结果吻合较好,可用于火灾后高强钢筋混凝土连续梁的鉴定评估。

     

    Abstract: An experimental study on the flexural behavior of reinforced concrete continuous T-beams with high strength bar at room temperature and after fire was conducted. The static loading test was accomplished for two control specimens. Three continuous beams were tested under fire with 30 min, 60 min and 90 min respectively according to ISO 834, and then the static loading test was accomplished after the beams were cooled to room temperature naturally. The temperature distribution of cross-section was measured during heating and cooling. The damage of beams after fire, and the deformation and failure mode of beams in the static loading test were also observed. The deteriorating laws of the flexural stiffness, ductility index, yield load and ultimate load of specimens after fire were studied and compared with the control specimens. For the temperature field of cross-section, the external temperature was high and the internal temperature was low during heating, but the external temperature was low and the internal temperature was high during cooling. When the exposed time was extended, the yield load and the ultimate load of beams had an parabolic decrease. The decrease of flexural stiffness was greater than that of the yield load and the ultimate load. The ductility index also had an obvious decrease. The numerical analysis results of temperature field and the flexural behavior after fire of RC continuous T-beam with high-strength bar agree well with the test results, which is expected to provide advice to appraisal and evaluation of RC structure after fire.

     

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