高性能纤维水泥基复合材料的制备与优化设计

发布时间：2019-06-02 17:27

【摘要】：本文研究了一种高性能纤维水泥基复合材料(也称工程水泥基复合材料,英文名为Engineering Cementitious Composites简称ECC)的制备与优化设计,旨在将ECC用于桥梁加固。首先,采用不同纤维、不同纤维掺量、不同水胶比、不同水泥粉煤灰比、不同砂胶比以及采用混掺纤维制作了ECC试件,围绕ECC的弯曲、拉伸、抗压强度和流动性等基本力学性能,进行了四点弯曲、直接拉伸、立方体抗压强度试验和跳桌试验。然后,使用喷射混凝土的机具测试了水胶比、水泥粉煤灰比和砂胶比对于ECC喷射施工效果的影响,考察了喷射回弹损失率、顺畅度、平整度等基本喷射性能指标。使用相同配合比,制作了ECC的喷射试件和浇筑试件,进行了四点弯曲和立方体抗压强度试验,对比了喷射和浇筑试件的弯曲延性和弯曲、抗压强度。最后,对ECC用于桥梁抗弯、抗剪、承压加固的承载力优势和成本优势,进行了分类讨论。围绕这些试验本文还进行了如下分析工作：(1)分析了ECC四点弯曲试验的荷载位移曲线图,从图中提取了等效抗拉强度、等效拉应变和ASTM韧性指数等指标,得出了纤维种类、纤维掺量、水胶比、粉煤灰水泥比、砂胶比和纤维混掺对ECC弯曲性能影响的结论。(2)分析了水胶比、粉煤灰水泥比对于ECC喷射顺畅度、平整度和附着性能的影响,得出了如何在浇筑ECC的基础上,使用差异化的配合比,制作喷射ECC的结论。(3)进行了FRP格栅增强ECC加固、粘贴FRP材加固法、增大截面加固法的抗弯、抗剪、抗压加固设计。考虑了每种加固方法的实际使用寿命,在此基础上提出了全寿命周期加固费用的概念。计算了每种加固方法达到相同抗弯、抗剪、抗压加固效果所需要的单次加固费用和全寿命周期加固费用。
[Abstract]:In this paper, the preparation and optimization design of a high performance fiber cement matrix composite (also known as engineering cement matrix composite, Engineering Cementitious Composites abbreviated as ECC) is studied in order to apply ECC to bridge reinforcement. First of all, different fibers, different fiber content, different water-binder ratio, different cement-fly ash ratio, different sand-binder ratio and mixed fiber were used to make ECC specimens, which revolved around the bending and drawing of ECC. The basic mechanical properties, such as compressive strength and mobility, were tested by four-point bending, direct tension, cube compressive strength test and table jumping test. Then, the effects of water-binder ratio, cement-fly ash ratio and sand-glue ratio on the effect of ECC spray construction were tested by using shotcrete machine, and the basic spray performance indexes, such as spray springback loss rate, smoothness and smoothness, were investigated. Using the same mix ratio, the spray specimen and pouring specimen of ECC were fabricated. The four-point bending and cube compressive strength tests were carried out, and the bending toughness, bending and compressive strength of spray and pouring specimens were compared. Finally, the bearing capacity advantages and cost advantages of ECC used in bending, shear and compression reinforcement of bridges are classified and discussed. The following analysis work is also carried out in this paper: (1) the load-displacement curve of ECC four-point bending test is analyzed, and the equivalent tensile strength, equivalent tensile strain and ASTM toughness index are extracted from the diagram, and the fiber types are obtained. The effects of fiber content, water-cement ratio, fly ash cement ratio, sand glue ratio and fiber mixture on the bending properties of ECC were analyzed. (2) the effects of water binder ratio and fly ash cement ratio on ECC jet smoothness, smoothness and adhesion were analyzed. On the basis of pouring ECC, it is concluded that how to make spray ECC by using differential mix ratio. (3) the bending, shear and compression reinforcement design of FRP grille reinforced ECC, bonded FRP material reinforcement method and section reinforcement method are carried out. Considering the actual service life of each reinforcement method, the concept of life cycle reinforcement cost is put forward. The single reinforcement cost and the whole life cycle reinforcement cost for each reinforcement method to achieve the same bending, shear and compressive reinforcement effect are calculated.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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