Effects of Asphalt Binder Additives and Industrial Fillers on the Mechanical and Functional Properties of Open Graded Friction Course

Abstract

Open graded friction course (OGFC) is widely recognized for its environmental and safety benefits (e.g., water drainage and noise reduction). However, based on durability concerns, many states have limited the use of OGFC. The objective of this study was to evaluate the effectiveness of warm mix asphalt (WMA) additives, by-products (i.e., crumb rubber [CR]), and industrial fillers (i.e., Portland cement and fly ash) in enhancing the laboratory performance of OGFC mixes. To achieve this objective, a comprehensive experimental program was conducted to evaluate the performance of eight mixes at three distinct stages (i.e., production, construction, and service). A suite of laboratory tests was conducted including draindown, prediction of compaction energy, Cantabro abrasion loss, Hamburg wheel tracking, Texas overlay, modified Lottman, and boiling tests to evaluate production, compaction, and OGFC resistance to raveling, permanent deformation, cracking, and stripping damage. Results indicated that CR, Portland cement, and fly ash significantly enhanced OGFC durability while maintaining adequate functional performance. In addition, results also showed that the use of an organic WMA additive considerably reduced the production temperature and compaction effort required to place the mix at the desired density while showing a significant improvement in OGFC durability.