火灾下CFRP加固RC梁高温抗弯承载力简化计算方法

复合材料科学与工程 ›› 2020, Vol. 0 ›› Issue (6): 10-17.

火灾下CFRP加固RC梁高温抗弯承载力简化计算方法

郝建文¹, 董坤^1*, 蒋济同¹, 胡克旭²

1.中国海洋大学工程学院,青岛266100;
2.同济大学土木工程学院,上海200092

收稿日期:2019-09-23 出版日期:2020-06-28 发布日期:2020-06-28
通讯作者: 董坤(1987-),男,讲师,博士,主要从事FRP加固结构及结构抗火方面的研究,dongkun2012@163.com。
作者简介:郝建文(1995-),男,硕士研究生,主要从事复合材料加固结构性能方面的研究。
基金资助:
中国博士后科学基金资助项目(2019M652477);中央高校基本科研业务费专项(841813023);青岛市博士后研究人员应用研究项目(861905042002)

SIMPLIFIED CALCULATION METHOD FOR HIGH TEMPERATURE FLEXURAL BEARING CAPACITY OF RC BEAMS STRENGTHENED WITH CFRP UNDER FIRE

HAO Jian-wen¹, DONG Kun^1*, JIANG Ji-tong¹, HU Ke-xu²

1. College of Engineering, Ocean University of Technology, Qingdao 266100, China;
2. College of Civil Engineering, Tongji University, Shanghai 200092, China

Received:2019-09-23 Online:2020-06-28 Published:2020-06-28

摘要/Abstract

摘要： 火灾下粘贴碳纤维复材(CFRP)加固构件的承载力计算是对其进行抗火设计的关键。采用数值模拟手段进行了标准火灾下单面和三面受火的CFRP加固钢筋混凝土(RC)梁温度场分析,考虑温度场的主要影响因素(保护材料厚度和导热系数),提出了加固构件表面及内部温度简化计算公式,并与试验数据对比验证了简化公式的准确性。结合混凝土梁截面承载力极限状态分析方法、材料及界面性能高温退化模型,建立了在ISO 834标准火灾情况下不同时刻CFRP加固RC梁高温抗弯承载力简化计算方法,并与荷载效应进行对比,即可进行防火保护材料厚度的合理选择。该研究成果可用于建立CFRP加固钢筋混凝土梁的火灾保护设计方法,或判断已有保护措施的CFRP加固梁是否能达到要求的耐火极限,能够为CFRP加固构件的抗火设计和安全鉴定提供理论手段和方法。

关键词: 混凝土结构, 纤维加固, 承载力, 火灾, 计算方法, 复合材料

Abstract: The calculation of bearing capacity of CFRP reinforced members under fire condition is the key to the fire resistance design. The temperature field of one-surface and three-surface exposed to fire of insulated CFRP reinforced RC beams under standard fire was analyzed by the finite element numerical simulation. Considering the influence of main factors (thickness and thermal conductivity of fireproof coating), a simplified formula for calculating the surface and internal temperatures of strengthened members is proposed. The accuracy of the simplified formula was well verified by comparing with the experimental data. By combining the analysis method of ultimate state of concrete beams section and the high temperature degradation model of material and interface properties, a simplified calculation method was established to calculate the high temperature bearing capacity of CFRP reinforced RC beams at different times under ISO 834 standard fire conditions. Compared the load capacity with the load effect, the reasonable thickness of fire protection materials could be determined. The research results can be helpful to establish the fire protection design method of CFRP reinforced RC beams, or to judge whether the existing CFRP reinforced beams can meet the requirement of fire resistance. The theoretical means and methods for fire resistance design and safety appraisal of CFRP reinforced structures were proposed.

Key words: concrete structure, FRP strengthening, loading capacity, fire, calculation method, composites

中图分类号:

TB332

郝建文, 董坤, 蒋济同, 胡克旭. 火灾下CFRP加固RC梁高温抗弯承载力简化计算方法[J]. 复合材料科学与工程, 2020, 0(6): 10-17.

HAO Jian-wen, DONG Kun, JIANG Ji-tong, HU Ke-xu. SIMPLIFIED CALCULATION METHOD FOR HIGH TEMPERATURE FLEXURAL BEARING CAPACITY OF RC BEAMS STRENGTHENED WITH CFRP UNDER FIRE[J]. Composites Science and Engineering, 2020, 0(6): 10-17.

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