聚丙烯粗纤维喷射混凝土冻融性能研究

发布时间：2018-05-11 05:19

本文选题：聚丙烯粗纤维 + 喷射混凝土　；参考：《现代隧道技术》2015年06期

【摘要】：为了研究聚丙烯粗纤维喷射混凝土在寒区隧道结构中应用的可行性,文章采用饱水快速冻融试验方法,得到了聚丙烯粗纤维喷射混凝土的质量损失率以及相对动弹性模量;根据冻融试验结果,分析了聚丙烯粗纤维喷射混凝土冻融破坏机理,建立了聚丙烯粗纤维混凝土的冻融损伤模型,并对其在自然条件下和隧道环境内的寿命进行了预测。研究结果表明:在提高抗冻性能方面,纤维最优体积率在0.9%左右;纤维对混凝土的抗冻性能是在纤维阻裂与纤维软弱界面两种作用下产生的结果;采用双段预测模型能有效地预测聚丙烯粗纤维混凝土的冻融循环次数,对我国不同地区喷射混凝土的寿命进行预测,可以作为聚丙烯粗纤维喷射混凝土耐久性定量设计的依据。
[Abstract]:In order to study the feasibility of the application of polypropylene coarse fiber shotcrete in tunnel structure in cold region, the mass loss rate and relative dynamic elastic modulus of polypropylene coarse fiber shotcrete are obtained by using the method of rapid freezing and thawing test. Based on the results of freeze-thaw test, the mechanism of freeze-thaw failure of polypropylene coarse fiber shotcrete is analyzed, the damage model of polypropylene coarse fiber concrete is established, and the life of polypropylene coarse fiber shotcrete under natural conditions and tunnel environment is predicted. The results show that the optimum volume ratio of fiber is about 0.9% in improving the frost resistance of concrete, and the freezing resistance of fiber to concrete is the result of the action of fiber crack resistance and fiber weak interface. The two-stage prediction model can effectively predict the freeze-thaw cycle times of polypropylene coarse fiber reinforced concrete and predict the life of shotcrete in different areas of China. It can be used as the basis for quantitative design of polypropylene coarse fiber shotcrete durability.
【作者单位】：西南交通大学交通隧道工程教育部重点实验室土木工程学院;中铁二院工程集团有限责任公司;
【基金】：国家自然科学基金(No.51278427) 高铁联合基金(U1134208) 中国中铁股份有限公司重点科技开发计划重大课题(No.重大-18-2011)
【分类号】：TU528

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