1. Study of the Cold Curing Characteristics of Isocyanate-Modified Asphalt
- Author
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Changhong Zhou, Mingli Peng, Xue Yang, Yating Qi, and Bin Xu
- Subjects
asphalt mixture ,isocyanates ,cold curing ,molecular dynamics simulation ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Isocyanate esters are widely recognized for their superior curing capabilities. Leveraging this attribute, the current research formulated a modified cold-mixed asphalt blend using 4,4′-methylene diphenyl diisocyanate (MDI). Tests and analyses of the MDI-modified asphalt with varying inclusion percentages of MDI revealed that a mixture containing 15% rock asphalt and 15% MDI-modified asphalt exhibited a more balanced, comprehensive performance. We also conducted an examination of the role and properties of MDI in asphalt modification using molecular dynamics simulations. The cold-curing properties of MDI-modified asphalt as compared to petroleum asphalt were evaluated based on its density, free volume analysis, cohesive energy density, and glass transition temperature. Implementing the LB-13 gradation—a cold-mixed asphalt gradation with a nominal particle size of 13.2 mm recommended by Chinese specifications—we prepared MDI-modified cold-mixed asphalt and carried out analyses of its mechanical characteristics, high-temperature performance, and water damage resistance. The results demonstrated that MDI-modified asphalt showcases excellent ductility, flexibility, and aging resistance, surpassing the performance of petroleum asphalt. The stability, high-temperature rutting, and water damage resistance of the MDI-modified cold-mixed asphalt exceeded the requirements for hot-mixed asphalt. This research provides theoretical and experimental support for isocyanate ester applications in asphalt engineering, presenting significant value for practical engineering applications.
- Published
- 2024
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