Improved performance of a reactive polymer-based bituminous mixes – effect of cross-linking agent

Abstract

Polymer-modified bitumen (PMB) is being practiced today worldwide as pavement performance boosters for ensuring its long life under extreme conditions of load, climate, traffic density, etc. Various national and international specs on the subject recommend a series of polymer chemistries for this application, but elastomeric polymers such as styrene–butadiene–styrene (SBS) are preferred due to their certain inherent advantages. However, universally a need is felt to allow the use of different classes of polymers, to enable producers of PMBs to cut cost through wider availability of polymers. Our research studies focused on preparing a PMB formulation, based on a reactive polymer, belonging to trans-polyoctenamer group. This research study showed that the PMB produced in the lab, by blending a reactive polyoctenamer polymer along with a trace amount of sulphur as a cross-linking agent, gives excellent performance almost equivalent to SBS-based PMB. There was a noticeable improvement in the elastic recovery properties.

Keywords:

• polymer-modified bitumen
• polyoctenamer
• sulphur
• SBS
• cross-linking
• elastic recovery
• reactive polymer

Acknowledgements

The authors are thankful to Director (R&D) Indian Oil Corporation, for his keen interest and permission to publish this work. We profusely thank Mr K.C Sharma, Mr R.S Negi, Dr Amol and Mr Chandrasekhar of our bitumen laboratory and scientists of the analytical group for support and helpful discussions. We also thank Dr Jain of Central Road Research Laboratory Delhi and Dr P. S. Viswanathan and Ms. Sonal Maheswari of Bharat Petroleum R&D Center, Noida, for permitting the use of some of their experimental facilities. The author, R.K. Padhan, is also thankful to Indian Oil R&D for providing the Indian Oil millennium research fellowship and providing full infrastructure support for this research.