Research On Physical Detection Method Of The Content Of SBS In Modified Asphalt

Polymer modified asphalt is a kind of asphalt that polymer modifiers are added in ordinary asphalt. Its engineering performance under relevant test is significantly better than conventional asphalt. There are a lot of kinds of polymer modified asphalt. At present, SBS modified asphalt has the largest proportion in polymer asphalt and is used widely because of its excellent road performance.The content of modifier and the processing quality of SBS modified asphalt are the key factors to control the quality of SBS modified asphalt and ensure the durability of asphalt pavement. The content of SBS directly affects all kinds of technical indicators of SBS modified asphalt. However, there is still no standard experimental methods used to detect the real content of SBS.In this thesis, according to the characteristics of SBS modified asphalt, firstly, we detect the content of SBS in modified asphalt by using the traditional Infrared Spectroscopy, Fluorescence Microscopy Technique and Gel Permeation Chromatography method. Infrared Spectroscopy can qualitatively detect the content of SBS in modified asphalt by using absorbance ratio and absorption peak area ratio of SBS and base asphalt. Fluorescence Microscopy Technique can observe the microscopic structure of modified asphalt and the distribution state of SBS in modified asphalt, and also can determine the content of SBS in modified asphalt rapidly and qualitatively. But it also has big errors due to human factors. Gel Permeation Chromatography method used for detecting the content of SBS in modified asphalt is feasible by analyzing the relationship between the change of characteristic peaks and SBS dosage in Gel Permeation Chromatography curves. Nevertheless, it sometimes also has large error phenomenon.Thermogravimetry Analysis in Thermal Analysis is used intensively to analyze the content of SBS in modified asphalt systematically based on the study of traditional test methods. TGA and DTG curves of modified asphalt samples with different contents of SBS are acquired. By analyzing the TGA and DTG curves, we find that the temperature corresponding to the third weight loss peak of3%-5%SBS modified asphalt has a linear regular characteristic. More accurate determination of the content of SBS in modified asphalt can be attained by using this regular characteristic.And this proves that TGA is a reliable method in the detection of the content of SBS in modified asphalt.50Figures,11Tables,58References...