Document Type : Research Paper
Authors
1
PhD Candidate of Raod and Transportation, Faculty of Civil Engineering, Semnan University, Semnan, I.R. Iran
2
Faculty of Civil Engineering, Semnan University, Semnan, Iran
3
Department of civil Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
Abstract
Bitumen, as one of the constituent elements of asphalt, plays an important role in the properties and performance of asphalt as well as its longevity and stability. However, its structure requires modification due to low mechanical properties, limited thermal stability, and susceptibility to cracking under environmental conditions. In this study, in order to increase strength and flexibility, improving functional and thermal properties, enhance adhesion, and prevent phase separation, a modifier based on NCO-terminated polyurethane/CNT were used. For this purpose, NCO-terminated polyurethane pre-polymer was prepared, and then CNTs were added to it at 0.5%, 1%, and 1.5% wt.%. Based on tensile and TGA tests, the sample containing 1.5% nanoparticles was selected as the optimum nanocomposite and subsequently combined with bitumen and then it was mixed with bitumen in percentages of 2, 4, 6 and 8 percent. FTIR test confirmed the chemical bonds between the nanocomposite and bitumen. To investigate the properties and performance of the resulting samples, morphological analysis, viscometry (RV) test, and rheological (DSR) tests for fatigue resistance and rutting under environmental conditions were performed. Also, results of multiple stress creep-recovery (MSCR) test was compared with results of rheology analysis and it was shown that the presence of nanocomposite in the structure of bitumen increased the elasticity and cohesion of the modified bitumen structure and it reduces the negative effects caused by the increase in stress and temperature in bitumen properties and the nanocomposite prepared in this research can be used as a suitable option to improve bitumen performance at high and medium temperature
Keywords
Main Subjects
)