Research in Progress (RIP) https://rip.trb.org/ en-us Copyright © 2024. National Academy of Sciences. All rights reserved. http://blogs.law.harvard.edu/tech/rss tris-trb@nas.edu (Bill McLeod) tris-trb@nas.edu (Bill McLeod) Research in Progress (RIP) https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg https://rip.trb.org/ Catalyst Regeneration of RAP-Binder in Asphalt https://rip.trb.org/View/1751141 25%) with virgin materials. This is a potential issue because the increasing percentage may adversely affect the performance of asphalt pavements, eventually resulting in higher pavement maintenance and rehabilitation costs. RAP-binders are difficult to reuse because they often contain associated molecules with very high molecular weights. Due to the polarity gained during oxidative aging, the asphaltene-type molecules form associated structures. These high molecular weight components are responsible for RAP-binder’s increased viscosity and certain deteriorated rheological properties. As a remedy, rejuvenators, softening agents, softer binders, and antioxidants can be added to asphalt that contains high amounts of RAP-binder to rebalance their rheological properties. Another approach to increase the amount of RAP-binder would be to modify the binder’s chemical composition with the help of a reagent or catalyst. Catalysts have been already positively impacting our lives with clean energy and green chemistry. This proposal will study effective ways to incorporate a high amount (> 25%) of RAP content in asphalt mixtures using a novel approach of introducing a catalyst that can disrupt the associated molecules formed during aging. The use of a catalyst such as a Lewis acid to break the associated molecules in the RAP-binder is a new promising approach. The project will investigate the effect of a Lewis acid catalyst such as Iron (III) chloride and Zinc chloride on the chemical composition of RAP-binder. These catalysts are known to catalyze the conversion of coal to liquid product, but the mechanism of action is not well understood. A detailed study of the chemical changes that occur to the RAP-binder before and after the modification will be carried out. The various virgin binder and RAP-binder blends with catalyst will be subjected to extensive chemical characterizations. This research is anticipated to facilitate the use of higher RAP contents in road construction. The outcomes of this study reduce the cost of highway construction and develop more environmentally friendly practices.]]> Tue, 10 Nov 2020 16:26:11 GMT https://rip.trb.org/View/1751141