CFRP加固钢筋混凝土梁耐火性能试验研究  

Fire resistance experiments of insulated CFRP strengthened reinforced concrete beams

作　　者：高皖扬[1] 胡克旭[1] 陆洲导[1] 

机构地区：[1]同济大学,上海200092

出　　处：《土木工程学报》2010年第3期15-23,共9页China Civil Engineering Journal

基　　金：国家自然科学基金资助项目(50578126)

摘　　要：采用厚型防火涂料和硅酸钙防火板对3根CFRP加固钢筋混凝土梁进行了不同方法的防火保护,在ISO834标准升温条件下进行耐火性能对比试验。分析了不同防火方法及端部锚固性能对高温下CFRP加固梁的温度场变化规律、跨中挠度、破坏形态及耐火极限的影响。试验研究表明:采用50mm厚防火涂料和40mm硅酸钙防火板对加固梁进行三面U型防火保护,耐火极限均可达到2.0h;提高CFRP的端部锚固性能可有效地改善加固梁的耐火性能;防火涂层中增设钢丝网片约束防火涂料、防止开裂和脱落效果明显。试验结果分析表明:CFRP加固混凝土梁防火保护的重点并非是CFRP材料本身,而是钢筋混凝土梁;可以通过延缓钢筋与混凝土材料的温度增长来推迟加固梁达到极限状态的时间,从而获得较好的耐火性能。This paper presents the results of full-scale fire resistance experiments of three CFRP strengthened reinforced concrete （RC） beams exposed to the ISO834 standard fire. Two different supplemental fire insulation materials （thick painted fire retardant coatings and calcium silicate board claddings） are examined through standard fire tests. The effects of different fire insulation systems and end anchorage behaviour of CFRP materials on the polymer adhesive temperature, midspan deflection, failure mode, and fire-resistance rating of the strengthened RC beams are investigated. The results suggest that ： when insulated with 50mm fire retardant coatings or 40mm calcium silicate board claddings, more than two hours of fire-resistance can be achieved for the loaded CFRP-strengthened RC beams ; fire-resistance performance of the strengthened beams can be effectively improved by upgrading the end anchorage behaviour of CFRP materials; and the additional steel wire mesh embedded in the insulated layers can prevent the layers from cracking and dropping in fire. It is demonstrated that, not the CFRP materials, but the RC beams are the emphasis for fire insulation. Through retarding the temperature increases of the steel rebar and core concrete, the insulation materials postpone the time when the strengthened beams reach the uhimate state under fire exposure, so that better fire-resistance performance can be achieved.

关 键 词：CFRP 加同 钢筋混凝土梁 防火保护 耐火性能 试验研究 

分 类 号：TU375.1[建筑科学—结构工程] TU352.5