不同纤维大坝混凝土的变形性能和抗裂性分析

发布时间：2018-02-28 05:47

本文关键词： 纤维混凝土力学性能变形性能抗裂性能　出处：《水力发电》2017年08期 　论文类型：期刊论文

【摘要】：选用PVA1、PVA2和PP三种不同厂家生产的纤维,通过试验研究了纤维对大坝混凝土力学性能和变形性能的影响,并对混凝土抗裂性进行了分析。结果表明,掺入三种纤维后混凝土的抗压强度、劈拉强度和轴拉强度均不同程度地降低;与基准混凝土相比,纤维混凝土干缩值均略有增加,自生体积变形收缩减小,且180 d龄期后纤维混凝土的变形均由微收缩型转变为微膨胀型,表明纤维可以抑制混凝土的自生体积收缩,有利于提高混凝土的抗裂性能;各加荷龄期PVA1纤维混凝土的徐变均大于相应基准混凝土,PVA2和PP纤维混凝土的徐变小于或等于基准混凝土;不同纤维对大坝混凝土抗裂性的改善效果不同,本研究采用的PVA1纤维对抗裂性的改善作用最优。在工程具体应用时需结合试验进行纤维材料优选。
[Abstract]:The effects of fiber on the mechanical and deformation properties of dam concrete were studied by using the fibers produced by PVA1 / PVA2 and PP, and the cracking resistance of concrete was analyzed. The compressive strength, splitting tensile strength and axial tensile strength of concrete mixed with three kinds of fibers decreased in varying degrees, and compared with the reference concrete, the dry shrinkage value of fiber reinforced concrete increased slightly, and the shrinkage of autogenous volume deformation decreased. The deformation of fiber reinforced concrete has changed from micro-shrinkage to micro-expansion after 180 days, which indicates that fiber can restrain the autogenous volume shrinkage of concrete and improve the crack resistance of concrete. The creep of PVA1 fiber concrete at each loading age is greater than that of the corresponding reference concrete or PP fiber concrete, and the improvement effect of different fibers on the crack resistance of dam concrete is different, and the creep of PVA1 fiber concrete is less than or equal to that of the corresponding reference concrete. The PVA1 fiber used in this study has the best effect on improving the crack resistance, and it is necessary to select the fiber material in combination with the test.
【作者单位】：中国水利水电科学研究院结构材料研究所;
【基金】：国家“十三五”重点研发计划项目(2016YFB0303600) 国家973计划重点基础研究发展规划项目(2013CB035901,2013CB035906) 国家自然科学基金项目(51409284) 中国水利水电科学研究院科研专项(SM0145B252014)
【分类号】：TV544

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