纤维高性能混凝土力学及耐久性能

发布时间：2019-03-01 13:20

【摘要】：结合某隧道工程跨海区间衬砌结构混凝土所处环境类别和作用等级,对不同纤维长度的聚丙烯纤维混凝土抗压性能及抗氯离子侵蚀耐久性能开展对比试验研究,提出掺加聚丙烯纤维的高性能混凝土方案,针对该方案配合比开展了轴心抗压试验、轴心抗拉试验、抗渗试验及干缩试验。结果表明:在早龄期(3~7 d),纤维混凝土的抗压强度略低于基准组抗压强度,而在后期(7~90 d),纤维混凝土抗压强度逐渐超过基准组抗压强度;28 d龄期混凝土抗压强度随纤维掺量的增加呈现增长的趋势;另外,当纤维掺量在1.5%以内时,随着纤维掺量的增加,28 d和90 d氯离子扩散系数皆随纤维掺量的增加而增加;纤维长度为6 mm的混凝土氯离子扩散系数略大于纤维长度为12 mm的混凝土氯离子扩散系数。
[Abstract]:Combined with the environmental category and action grade of concrete lining structure in cross-sea section of a tunnel project, the compressive properties and corrosion resistance of polypropylene fiber concrete with different fiber lengths were compared and studied. A scheme of high performance concrete mixed with polypropylene fiber was put forward. Axial compression test, axial tensile test, impermeability test and dry shrinkage test were carried out according to the mix ratio of the scheme. The results show that the compressive strength of the fiber reinforced concrete at the early age (3 / 7 d),) is slightly lower than that of the reference group, but at the later stage (7 / 90 d), the compressive strength of the fiber reinforced concrete gradually exceeds that of the reference group. The compressive strength of 28-day-old concrete increases with the increase of fiber content. In addition, when the content of fiber is less than 1.5%, the chloride diffusion coefficient of 28 d and 90 d increases with the increase of fiber content. The chloride diffusion coefficient of concrete with fiber length of 6 mm is slightly higher than that of concrete with fiber length of 12 mm.
【作者单位】：南京水利科学研究院水文水资源与水利工程科学国家重点实验室;南京水利科学研究院国家能源水电工程安全与环境技术研发中心;
【基金】：国家自然科学基金(51509167,51579155) 江苏省自然科学基金(BK20150076)
【分类号】：TU528

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