EXPERIMENT STUDY ON SHEAR PROPERTIES OF RC BEAMS UNDER HIGH TEMPERATURE
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摘要: 通过对8根足尺钢筋混凝土梁进行恒载-升温条件下的火灾试验,分析不同边界条件、剪跨比及箍筋间距对梁高温下抗剪性能的影响,研究梁受火过程中截面混凝土的温度场、箍筋及纵筋的温度变化,梁的竖向位移、梁端水平位移及梁的最终裂缝开展形式,对比了不同参数影响下各梁的耐火极限。结果表明:剪跨比对钢筋混凝土梁高温下的抗剪性能影响显著,剪跨比越小,梁发生剪切破坏时的耐火极限越高,但破坏时的脆性特征更加明显;火灾下,随着箍筋间距的增加,梁的耐火极限降低;与常温下不同,高温下约束梁由于发生了内力重分布,其抗剪性能优于简支梁。Abstract: Eight full-scale reinforced concrete (RC) beams were tested for fire resistance. The effect of boundary conditions, shear span to effective depth ratios, stirrup spacings on shear properties of beams at high temperature was analyzed. The thermal fields within beams, variations of temperature of reinforcing bars, vertical and horizontal displacement and crack developing modes of beams were studied. The fire resistance of RC beams with different parameters was compared. The results showed that the shear span to effective depth ratios had significant influence on shear properties of beams at high temperature, with shear span to effective depth ratios decreased, the fire resistance of beams was improved, however, the failure characteristics of beams were obviously brittle. With stirrup spacings of beams increased, fire resistance of beams was decreased in fire. Different from at room temperature, fire resistance of simply supported beams was better than that of restrained beams, due to internal force redistribution of beams at high temperature.
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王全凤, 邱毅, 徐玉野,等. HRBF50钢筋混凝土梁受火后动力性能试验和温度场数值模拟[J]. 工业建筑, 2012, 42(10):47-52. 廖艳芬, 漆雅庆, 马晓茜. 火灾下钢筋混凝土梁非线性有限元分析[J]. 工业建筑,2011, 41(7):31-37. 张威振. 足尺钢筋混凝土简支梁高温力学性能的试验研究[J]. 工业建筑, 2007, 37(4):37-41. 丁发兴, 姚飞, 李哲, 等. 高温下钢筋混凝土简支梁的的抗火性能[J]. 东北大学学报,2015, 36(10):476-1481. 吴波, 乔长江. 混凝土约束梁升降温全过程的耐火性能试验[J]. 工程力学,2011, 28(6):88-95. 袁广林, 黄方意, 吕志涛. 高温(火灾)对无黏结部分预应力混凝土梁抗弯性能的影响[J]. 建筑结构,2007, 37(1):105-108. 郑文忠, 陈伟宏, 侯晓萌. 火灾后配筋混凝土梁受力性能试验与分析[J]. 哈尔滨工业大学学报,2008, 40(12):1861-1867. 傅传国, 王玉镯, 于德帅, 等. 火灾作用下预应力型钢筋混凝土简支梁承载性能试验研究[J]. 防灾减灾工程学报, 2012, 32(1):1-6. GAO W Y, DAI J G, TENG J G, et al. Finite Element Modeling of Reinforced Concrete Beams Exposed to Fire Engineering Structures[J]. Engineering Structures, 2013, 52(7):488-501. LIN X S, ZHANG Y X. Nonlinear Finite Element Analyses of Steel/FRP-Reinforced Concrete Beams in Fire Conditions[J]. Composite Structures, 2013, 97(3):277-285. DWAIKAT M B, KODUR V K R. Response of Restrained Concrete Beams Under Design Fire Exposure[J]. Journal of Structural Engineering, 2009, 135(11):1408-1417. EAMON C D, JENSEN E. Reliability Analysis of Prestressed Concrete Beams Exposed to Fire[J]. Engineering Structures, 2012, 43(10):69-77. British Standards Institution. Design of Composite Steel and Concrete Structures:Eurocode 4[S]. London:British Standards Institution, 2006.
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