Effect of modified heavy calcium carbonate on properties of crumb rubber modified asphalt binder

ABSTRACT

High-temperature rutting is one of the common forms of pavement damage. To further improve the high temperature performance of crumb rubber modified asphalt (CRMA) pavement, heavy calcium carbonate (HCC) modified by sodium pyrophosphate was combined with crumb rubber to prepare composite modified asphalt binder. Their physical properties, viscoelastic properties and chemical composition were investigated through conventional physical tests, DSR, FTIR and fluorescence microscopes. The results show that with the increase of HCC content, the mixing and compaction temperatures of composite modified asphalt binders continued to increase. Further, the high temperature performance and fatigue resistance of binders were better than the original CRMA, due to the enhanced lipophilicity of HCC after modification. It can be found from the FTIR spectrum that the addition of HCC only existed in physical action. However, excessive HCC would cause agglomeration of the asphalt matrix, so the optimum dosage of HCC was determined to be 4%.

KEYWORDS:

• Asphalt binder
• Calcium carbonate
• Rheological properties
• Microstructural analysis

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The raw data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Additional information

Funding

This research is supported by the National Natural Science Foundation of China (51108374), Jiangxi Transportation Science and Technology Project (2016C0005), the Key R&D Program Funding Project of Shaanxi Province (2018SF-380) and the Special Fund for Basic Scientific Research of Central Colleges, Chang’an University (300102310301, 300102311404).