改性沥青SBS含量电化学检测方法适用性及质量控制研究

发布时间：2018-11-08 12:46

【摘要】：聚合物SBS改性沥青凭借突出的高温性能、低温性能、弹性恢复性能及感温性能,在高等级公路建设中得到广泛应用。但是,由于当前国内外仍没有标准、快速、精确的检测方法用于SBS掺量检测,无法做到改性沥青中SBS真实掺量的即时监管,严重影响了质量管理人员对SBS改性沥青路用性能的真实、客观评价。本课题组中南大学朱自强、刘正春教授等人在分析总结前人研究成果后,基于SBS分子碳碳双键加成氧化特性,提出了通过加成氧化还原反应方法来精确计量碳碳双键数量。基于这一思想,SBS课题组经反复试验研究提出了一套SBS含量检测新方法,即“SBS掺量电化学分析法”。该检测法的核心原理是用已知量的加成试剂与沥青中SBS发生加成反应,再通过氧化还原滴定试验求得加成试剂的消耗量,从而间接性求出沥青中SBS的数量。SBS含量电化学分析法能够稳定、快速、精确的实现SBS掺量检测,检测精度可达±0.1%。针对不同SBS种类、掺量及各种外掺剂,设计实验制备多种配比的改性沥青,通过实验论证了“SBS含量电化学分测法”的适用性。试验结果表明该检测方法能够精确检测各种配比改性沥青中的SBS掺量,有着很好的适用性;此外还分析了增容剂、稳定剂、纳米蒙脱土等添加剂对检测精度的影响,确保了该检测方法在实际工程应用中能获得准确的检测结果。基于SBS掺量电化学分析法,选取三组成品改性沥青做储存稳定性评价。对离析试样上下部沥青做软化点测试、SBS含量检测及动态剪切流变(DSR)试验(测试车辙因子,计算沥青离析率),结合软化点差、SBS含量、离析率三相指标综合评价三组成品沥青的储存稳定性。试验结果表明:离析软化点试验能较好评价线型SBS改性沥青的储存稳定性,但对星型SBS改性沥青离析程度评价存在较大误差;SBS掺量电化学分析法可直接检测离析后上下部沥青中SBS实际含量值,能准确评价改性沥青的储存稳定性;动态剪切流变实验需要根据沥青高温性能选取合理试验温度,否则不能很好地评价改性沥青的储存稳定性。通过盲样测试,改性沥青SBS掺量电化学分析术的有效性和检测准确性得到了充分的验证;SBS掺量电化学分析术在实际工程检测应用中取得了良好效果,说明本检测技术具有良好的工程检测适用性。
[Abstract]:Polymer SBS modified asphalt is widely used in highway construction because of its outstanding properties of high temperature, low temperature, elastic recovery and temperature sensing. However, because there is still no standard at home and abroad, the rapid and accurate detection method used in SBS content detection, can not achieve the real content of SBS in modified asphalt real-time supervision, It seriously affects the real and objective evaluation of the road performance of SBS modified asphalt by quality managers. Zhu Ziqiang and Liu Zhengchun of Zhongnan University in our research group, after analyzing and summarizing the previous research results, based on the carbon and carbon double bond addition and oxidation characteristics of SBS molecule, a method of addition redox reaction is proposed to accurately measure the number of carbon and carbon double bonds. Based on this idea, a new method for the determination of SBS content was proposed by the SBS team through repeated experiments. It was called "Electrochemical Analysis of SBS content". The core principle of this detection method is to react with SBS in asphalt with known addition reagents, and then determine the consumption of addition reagents by redox titration test. Therefore, the quantity of SBS in asphalt can be obtained indirectly. The electrochemical analysis method of SBS content can realize the detection of SBS content stably, quickly and accurately, and the detection accuracy can reach 卤0.1. According to different kinds of SBS, the amount of SBS and various admixtures, the modified asphalt with various proportions was designed and prepared. The applicability of "electrochemical method for the determination of SBS content" was proved by experiments. The test results show that this method can accurately detect the content of SBS in various proportion modified asphalt, and it has good applicability. In addition, the influence of compatibilizer, stabilizer, nano-montmorillonite and other additives on the detection accuracy is also analyzed, which ensures that the detection method can obtain accurate results in practical engineering application. Based on SBS electrochemical analysis, three groups of modified asphalt were selected for storage stability evaluation. Softening point test, SBS content test and dynamic shear rheological (DSR) test (measuring rutting factor, calculating bitumen segregation rate), combining softening point difference, SBS content, etc. The storage stability of three groups of finished asphalt was evaluated synthetically by three-phase index of segregation rate. The results show that the segregation softening point test can better evaluate the storage stability of linear SBS modified asphalt, but there is a great error in the evaluation of segregation degree of star-shaped SBS modified asphalt. SBS admixture electrochemical analysis method can directly detect the actual content of SBS in the upper and lower asphalt after segregation, and can accurately evaluate the storage stability of modified asphalt. Dynamic shear rheological experiments need to select reasonable test temperature according to the high temperature performance of asphalt, otherwise, the storage stability of modified asphalt can not be evaluated very well. The validity and accuracy of the electrochemical analysis of SBS content of modified asphalt were fully verified by blind sample test. SBS admixture electrochemical analysis technique has achieved good results in practical engineering detection, which shows that this detection technology has good applicability in engineering detection.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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