| SBS modified asphalt road with its superior is widely used in road engineering,but due to the high price of SBS modifier,some asphalt manufacturers make up of shoddy and use some scrap rubber as SBS modifier,or by adding admixtures to reduce the amount of SBS modifier,so the quality of the SBS modified asphalt regulation is also a problem in the transportation industry.There are many problems such as long test period,large human interference,low accuracy,time-consuming and laborious in the conventional three indicators testing SBS modified asphalt quality,which can not be completed quickly and conveniently.Over the years,many researchers in the transportation industry in various countries have conducted a lot of research and developed a variety of rapid detection methods,such as infrared spectroscopy,fluorescence microscopy,gel permeation chromatography,thermal weightlessness,chemical titration,electrochemistry Methods,and the most widely used is the infrared spectroscopy.According to the application summary for many years,this technology needs to improve the test accuracy and improve the applicability in engineering projects.In this paper,based on the infrared spectrum test technology,the factors that affect the test accuracy are studied and the factors affecting the test accuracy are studied.By improving the method of sample preparation and model algorithm to eliminate the influence of some factors,the boundary conditions of the test technology are simplified,and the preparation of standard samples does not need to add additives,but also can accurately test the content of modifier,which improves the safety,convenience,applicability and accuracy of the test technology.The main research contents are summarized as follows:1)Principle and method analysis of SBS modifier content by infrared spectroscopyThe existing infrared spectrum testing technology is analyzed,and the application mechanism of SBS modifier content testing is revealed through the infrared spectroscopy rules such as Lambert-Beer law and additivity;by the introduction of key technologies such as sample preparation technology,infrared spectroscopy reading rules and the establishment of standard curves and equations,the specific method of infrared spectroscopy technology in the SBS modifier content test is clarified.2)Research on the influence of different types and contents of SBS modifiers on the accuracy of content testing.The contents of four different SBS modifiers,2%,3%,4%,5%,6%five SBS modifiers were studied,and the test accuracy was not more than±0.1%,satisfying the allowable error range.which indicated that different types and contents of SBS modifiers would not affect the test accuracy.When using the standard curves of different groups to determine the content of the same SBS modified asphalt,the error range of the different groups exceeds±0.1%,which indicated that the standard curves of different types of modifiers cannot be used universally.3)Research on the influence of additives on the accuracy of SBS modifier content test.The physical admixtures do not cause chemical reaction of SBS modified asphalt,but the physically miscible.The quality error will be generated after the addition,which exceeds the allowable error range of±0.1%.After the quality error is removed,there is no effect on the accuracy of content determination of SBS modifier.The reactive admixtures cause the chemical reaction between matrix asphalt and SBS modifier.After removing the quality error,it still far exceeds the allowable error range of±0.1%,which has a great influence on the accuracy of content determination.4)Research and improvement of sample preparation technology and model algorithm.4)Research and improvement of sample preparation technology and model algorithm.A new sample preparation technique-dissolution method is proposed,the improved sample preparation technique dissolution method significantly improves the safety,convenience,applicability and accuracy of the test,and can be used as a new transmission sample preparation technique for the determination of SBS modifier content.The 699cm-1 characteristic peak was re selected to replace the 966cm-1 characteristic peak,and a new calculation model was established.After the mass error was removed,the test accuracy met the allowable error range of±0.1%.It can be used as a new model algorithm to determine the SBS modifier content,to simplify the boundary conditions,to prepare standard samples without adding additives,and to accurately test the modifier content. |
