玄武岩纤维对C40混凝土高温后碳化的抑制作用  

Inhibition mechanism of basalt fiber on the carbonation of C40 concrete after exposure to high temperature

作　　者：钟曦[1] 张超[1] 张博超[1] 李宇航 卢丽敏 秦钰雯 姬永生 ZHONG Xi;ZHANG Chao;ZHANG Bochao;LI Yuhang;LU Limin;QIN Yuwen;JI Yongsheng(CNOOC Gas Group,Beijing 100028,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 200016,China)

机构地区：[1]中海石油气电集团有限责任公司,北京100028 [2]中国矿业大学力学与土木工程学院,江苏徐州200016

出　　处：《混凝土》2024年第10期16-20,31,共6页Concrete

基　　金：国家自然科学基金面上项目(51972337)。

摘　　要：隧道衬砌混凝土的碳化问题尤为突出,而玄武岩纤维混凝土(BFRC)作为适用于隧道结构的高性能混凝土,其在常温下和火灾后的碳化机理尚不明确。开展了C40混凝土和玄武岩纤维混凝土的高温试验和快速碳化试验,监测了BFRC碳化深度的发展规律。基于半经验半理论模型,引入混凝土高温烧损层深度和高温后碳化速率等参数,建立了BFRC高温后碳化深度预测模型,分析了玄武岩纤维对混凝土高温后碳化深度发展的抑制作用。结果表明:掺入适量玄武岩纤维后,混凝土常温下碳化速率降低为原来的82%,高温烧损层深度大大降低,高温后碳化系数随温度的升高降低比例从21.5%达到37.5%,明显抑制了高温对混凝土碳化发展的影响,从而显著提高了混凝土的抗碳化性能。The carbonation of concrete is one of the critical factors influencing concrete durability,which is also a prominent problems of tunnel lining structures especially a fire disaster is happened.As a kind of high-performance concrete that suitable for tunnel lining structures,the carbonation mechanism of basalt fiber reinforced concrete(BFRC)at room temperature and after submitted to high temperature is not clear.In order to study the carbonation resistance of BFRC,release the inhibition mechanism of basalt fiber on the development of carbonation depth,heating tests and rapid carbonation experiments after heating were carried out,on specimens of both C40 ordinary concrete and BFRC.The burnt layer depths of the two concretes were compared,the carbonation factors and carbonation high temperature influencing coefficients of concrete after submitted to high temperatures were calculated.Based on the existing semi-empirical and semi-theoretical model and the test results,a numerical model for predicting carbonation depth of concrete after exposure to high temperatures was generated.The results show that basalt fiber can effectively constrain the carbonation factor of concrete both at room temperature and high temperature,reduce the burnt layer depth and carbonation velocity of concrete,which makes the BFRC has a better carbonation resistance compares to normal concrete.

关 键 词：玄武岩纤维 高温 烧损层 碳化深度 碳化系数 抑制作用 

分 类 号：TU528.572[建筑科学—建筑技术科学]