玄武岩纤维活性粉末混凝土基本性能试验研究

发布时间：2018-04-11 03:35

  本文选题：活性粉末混凝土 + 玄武岩纤维　； 参考：《北京交通大学》2013年硕士论文

【摘要】：活性粉末混凝土作为一种新型混凝土材料,具有良好的物理力学性能与应用前景。钢纤维的掺入虽然能够增强增韧活性粉末混凝土的力学性能,但由于钢纤维存在锈蚀的风险,因此这样对活性粉末混凝土在氯离子和除冰盐环境等极端恶劣环境下的耐久性可能会造成不利影响。玄武岩纤维作为一种新型的硅酸盐纤维,具有高强度、高弹模、良好的耐高温性等优良特性。若能用玄武岩纤维替代钢纤维掺入活性粉末混凝土,对提高极严酷环境下活性粉末混凝土结构的耐久性具有重要意义。 本文尝试在活性粉末混凝土中加入玄武岩纤维代替钢纤维,对玄武岩纤维活性粉末混凝土的基本力学性能与耐久性进行了试验研究,主要研究结果如下： 1.研究了纤维长度(6mm、12mm)和体积掺量(0.0%、0.5%、1.0%、1.5%、2.0%)对活性粉末混凝土的立方体抗压强度、劈裂抗拉强度等强度指标的影响,研究认为玄武岩纤维对活性粉末混凝土的力学性能有一定的影响,且随着纤维掺量的增大,活性粉末混凝土的抗压强度、劈裂抗拉强度、抗折强度均呈现先增大后减小的趋势。6mm的玄武岩纤维活性粉末混凝土的最佳掺量为1.0%,12mm的玄武岩纤维活性粉末混凝土的最佳掺量为1.5%。 2.通过研究玄武岩纤维体积掺量分别为0.0%、1.0%、2.0%的活性粉末混凝土的单轴受压的荷载和应变值,得到其单轴受压的应力应变曲线。在已有单轴受压应力应变本构模型方程式的基础上,分别得出了不同玄武岩纤维掺量情况下的应力-应变关系方程。 3.测定了玄武岩纤维体积掺量分别为0.0%、1.0%、2.0%的玄武岩纤维活性粉末混凝土的电通量,得出结论玄武岩纤维活性粉末混凝土的电通量均在12C以下,其内部结构均匀致密。 4.使用SEM方法研究玄武岩纤维净浆试件和玄武岩纤维材料在Ca(OH)2饱和溶液中75℃蒸汽养护三天后的微观形貌。研究结果表明：玄武岩纤维在高温强碱溶液中产生轻微腐蚀,在高温蒸汽养护的净浆试件中也有轻微的腐蚀现象,这种腐蚀程度基本不会对混凝土力学性能和耐久性造成严重影响。
[Abstract]:As a new type of concrete material, reactive powder concrete has good physical and mechanical properties and application prospects.Although the addition of steel fiber can enhance the mechanical properties of toughened reactive powder concrete, but because of the risk of corrosion of steel fiber,Therefore, the durability of reactive powder concrete under extreme conditions, such as chloride ion and deicing salt environment, may be adversely affected.As a new silicate fiber, basalt fiber has high strength, high modulus of elasticity and good high temperature resistance.If basalt fiber can be used instead of steel fiber to add reactive powder concrete, it is of great significance to improve the durability of reactive powder concrete structure under extremely harsh environment.In this paper, basalt fiber is used to replace steel fiber in reactive powder concrete. The basic mechanical properties and durability of reactive powder concrete with basalt fiber are studied. The main results are as follows:1.The effects of fiber length of 6 mm / 12mm) and volume content of 0. 0 ~ 0. 5) on the cube compressive strength and split tensile strength of reactive powder concrete (RPC) were studied. The results show that basalt fiber has a certain effect on the mechanical properties of RPC.And with the increase of fiber content, the compressive strength and splitting tensile strength of reactive powder concrete,The flexural strength of basalt fiber reactive powder concrete increased first and then decreased. The optimum content of basalt fiber reactive powder concrete with 1.0 ~ 12 mm basalt fiber reactive powder concrete was 1.5mm.2.By studying the uniaxial compression load and strain value of reactive powder concrete (RPC) with the volume content of basalt fiber being 0.010% and 2.0% respectively, the stress-strain curves of the concrete under uniaxial compression are obtained.On the basis of the constitutive equation of uniaxial compression stress-strain model, the stress-strain relation equations under different basalt fiber content are obtained.3.The electric flux of basalt fiber reactive powder concrete with volume addition of 0.010% basalt fiber and 2.0% basalt fiber reactive powder concrete has been measured. It is concluded that the electric flux of basalt fiber reactive powder concrete is below 12C, and its internal structure is uniform and compact.4.SEM method was used to study the microstructure of basalt fiber samples and basalt fiber materials after three days of steam curing at 75 鈩，

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