沥青填充式桥梁无缝伸缩缝材料的制备与性能研究

发布时间：2018-03-06 03:27

  本文选题：无缝伸缩缝　切入点：高低温性能　出处：《武汉理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：沥青填充式桥梁无缝伸缩缝是一种沥青混合料填充式的伸缩缝，由于其特有的优势在欧美国家得到了广泛的应用。无缝伸缩缝必须同时承受伸缩变形和行车载荷作用，因而必须同时具备优异的高低温性能。如何兼顾材料的低温柔韧性和高温抗变形能力是本文的一个难点。本文通过复合改性的方法制备出伸缩缝沥青胶结料，并在规范指标的基础上对其性能进行了深入的研究。 伸缩缝沥青胶结料配方制定结果表明，轻质油分可以较好的解决低标号沥青改性效果差以及低温性能差的问题。SBS可以很大程度改善沥青的高温稳定性，而橡胶粉则可以改善沥青的低温柔韧性和耐久性，但这两种改性剂单独使用都不能满足伸缩缝胶结料的性能要求；利用SBS和橡胶粉配以轻质油分同样无法调和高低温性能之间无法共存的矛盾；而在SBS/橡胶粉复合改性的基础上引入抗车辙剂之后，得到的沥青胶结料性能满足规范要求。 对性能满足要求的沥青胶结料进行流变性、稳定性和耐久性的研究。结果表明，沥青胶结料高温下具有相对很高的模量，而低温下的模量又相对很低，与进口材料处在同一水平，高低温的相位角仅在25.9°到41.6°的范围，温度敏感性低，高温抗变形能力和低温应力松弛能力良好。短期老化之后，常规性能指标变化不大，模量略有降低，，相位角则略有升高，且高温区的变化更为明显，老化之后高温等级下降16℃。热储存之后，上下部分软化点差仅为1.8℃，流变性能基本一致。 同时对伸缩缝沥青混合料进行高低温性能的研究。结果表明，沥青混合料在60℃的动稳定度达到1167次/mm，满足项目提出的1000次/mm要求的同时也达到了进口材料的水平，且车辙深度要明显小于进口材料。在-10℃的温度下，伸缩缝沥青混合料最大弯拉应变达到36734μm/m，远高于文献提出的10000μm/m的标准，-20℃下的最大弯拉应变则达到7987μm/m，和进口材料处于同一水平。在-10℃和-20℃的温度下，伸缩缝混合料的应力松弛速度相当快，t75（应力松弛掉75%所花时间）分别为64s和61s，完全满足15min的评价标准，残留应力都在0.1MPa的数量级。足尺模拟拉伸试验结果表明，拉伸过程中跨缝钢板边缘位置的变形量最大，对总体变形的贡献率最大，在该位置最容易出现开裂破坏。
[Abstract]:The seamless expansion joint of asphalt filled bridge is a kind of asphalt mixture filled expansion joint, which has been widely used in Europe and America because of its unique advantages. Therefore, it is necessary to have excellent high and low temperature properties at the same time. How to combine the low temperature flexibility and the high temperature deformation resistance of the materials is a difficult point in this paper. In this paper, the expansion joint asphalt binder is prepared by the method of compound modification. And on the basis of the specification of the performance of the in-depth study. The formulation of asphalt binder for expansion joint shows that light oil content can solve the problem of poor modification effect and low temperature performance of low grade asphalt. SBS can greatly improve the high temperature stability of asphalt. Rubber powder can improve the low temperature flexibility and durability of asphalt, but these two modifiers alone can not meet the performance requirements of expansion joint binder. Using SBS and rubber powder with light oil can not reconcile the contradiction between high and low temperature performance, but after introducing rutting resistant agent on the basis of compound modification of SBS/ rubber powder, the properties of asphalt binder can meet the requirements of specifications. The rheological properties, stability and durability of asphalt binders are studied. The results show that asphalt binders have relatively high modulus at high temperature and relatively low modulus at low temperature. At the same level as the imported materials, the phase angle of high and low temperature is only in the range of 25.9 掳to 41.6 掳, the temperature sensitivity is low, the deformation resistance at high temperature and the relaxation ability at low temperature are good. The modulus decreases slightly, the phase angle increases slightly, and the change of high temperature region is more obvious. After aging, the grade of high temperature decreases by 16 鈩

本文编号：1573158