路用自修复材料的制备及性能研究

发布时间：2018-08-12 18:48

【摘要】：在正常使用环境下，沥青混合料无可避免的会出现微小开裂。如果这些病害不能被及时修复，微裂纹会进一步扩展、汇聚，进而形成裂缝，影响沥青路面的正常使用性能和服役寿命。 本文引入生物自修复的概念，以物质补充为手段，利用微胶囊技术将再生剂包覆并添加在沥青中。当微裂缝扩展至微胶囊处时，微胶囊囊壁破裂，流出的再生剂不但能改善裂纹处沥青的性质、同时促使裂纹处沥青能够在室温下或较低温度下自行愈合，从而延缓裂缝的扩展甚至完全修复裂缝，延长沥青路面的服役寿命。论文主要研究内容与结论如下： 1.分析了现有微胶囊技术的优势与不足，本文确定了原位聚合法制备沥青自修复微胶囊，囊壁材料为脲醛树脂，囊芯材料为自制沥青再生剂A。本文详细探寻了再生剂微胶囊的制备工艺，得出了制备微胶囊的最佳反应条件：①将甲醛与尿素摩尔比为1.5:1的溶液在PH约为8的碱性环境下，60~75℃反应60~75min得到脲甲醛预聚体；②再生剂乳化阶段所用的表面活性剂为十二烷基苯磺酸钠，浓度为0.5wt%；再生剂乳化阶段转速为800r/min；③再将乳化好的再生剂溶液加入预聚体中，控制搅拌速率为500r/min，囊芯与囊壁质量比为1.2:1，稀盐酸缓慢调节溶液至PH=3，同时缓慢升温至60℃,2~3h后反应结束；④放慢搅拌速度继续搅拌冷却至室温，再将含有微胶囊的悬浮液过滤、洗涤、干燥制得微胶囊。对制备出的微胶囊结构性能进行分析，结果表明，微胶囊形貌良好，表面致密，包覆率为84.94%，囊芯含量为82.46%，平均粒径为21.14um，分布主要集中在5um到35um之间，该部分微胶囊占总体的73.0%。 2.通过自愈合延度试验和自愈合DSR试验研究了再生剂微胶囊对沥青自修复能力的影响。自愈合延度试验分析可知：微胶囊掺量为0.3wt%时，对于沥青的自修复能力有明显提升，且不会大幅降低沥青性质。自愈合DSR试验数据表明：微胶囊掺量为0.1wt%的沥青在初次疲劳试验中加载时间为1120s，抗疲劳能力最强；掺量为0.5wt%的沥青在再疲劳试验中加载至破坏的时间为449s，经愈合后的抗疲劳能力最强，说明它的愈合效果较好，自修复能力最强。得出结论，少量掺量的微胶囊能够有效增加沥青的疲劳寿命，随着微胶囊掺量的增大，沥青的整体疲劳寿命减小，，但自修复能力增强。
[Abstract]:In the normal use environment, asphalt mixture will inevitably appear minor cracking. If these diseases can not be repaired in time, the microcracks will further expand and converge, thus forming cracks, which will affect the normal service performance and service life of asphalt pavement. In this paper, the concept of bioremediation is introduced. By means of material supplement, the regenerative agent is coated and added to asphalt by microencapsulation technology. When the microcrack extends to the microcapsule, the microcapsule wall breaks, and the regenerating agent can not only improve the properties of the crack asphalt, but also promote the crack asphalt to heal itself at room temperature or at lower temperature. In order to delay the expansion of cracks and even completely repair cracks, extend the service life of asphalt pavement. The main contents and conclusions are as follows: 1. The advantages and disadvantages of the existing microencapsulation techniques were analyzed. In this paper, the self-repairing asphalt microcapsules were prepared by in-situ polymerization. The wall materials were urea-formaldehyde resin and the core materials were self-made asphalt regeneration agent A. In this paper, the preparation process of regenerative microcapsules was studied in detail, and the optimum reaction conditions for the preparation of microcapsules were obtained. The optimal reaction conditions: 1: 1 reacted the solution with the molar ratio of formaldehyde to urea 1.5: 1 in the alkaline environment of PH about 8 to obtain the urea-formaldehyde prepolymer at 6075 鈩

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