01663683

Component

Asphalt oxidation (aging) results in the hardening of the asphalt and a reduction in its ability to relax stress. Consequently, aged asphalt will retain stress for a longer time under loading, and that stress will be larger than for unaged asphalt. Ultimately, aging will lead to cracking and failure of asphalt pavement through a combination of thermal and traffic-induced stresses. There has been an increasing emphasis on aging of binder to evaluate in-service cracking performance. This study is focused on longer aging durations and the impacts on binder cracking resistance and rheological properties. The primary goal of this paper is to develop an understanding of asphalt binder susceptibility to oxidation in quantitative terms that can be used as material selection criteria. Another important goal is to understand how oxidation intensity (or duration) changes mechanical (rheological) properties of the asphalt binder. Twelve binders (neat and modified) from field projects visited by the FHWA’s Mobile Asphalt Testing Trailer are tested to investigate the effect of different aging levels on binder fundamental properties as well as cracking behavior. In addition to standard Performance Grade (PG) testing, the Asphalt Binder Cracking Test (ABCD) was used to assess thermal cracking properties of binders. Analysis of the shear modulus master curves is conducted to explore how extended conditioning affects different rheological parameters, such as rheological index and cross-over frequency. Furthermore, other suggested cracking indicators, such as the difference between the stiffness-based and slope-based low temperature continuous PG (ΔTc)) and Glover-Rowe parameter, are utilized to evaluate the influence laboratory aging has on material behavior. Results at extended conditioning level reinforced the need to run 40 hours PAV since the prediction of rheological parameters are not accurate enough given the suggested criteria.

This paper was sponsored by TRB committee AFK20 Standing Committee on Asphalt Binders.

18-06036

English

8p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Aging (Materials); Bituminous binders; Oxidation; Pavement cracking; Pavement distress; Rheological properties; Stress cracking

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2018 Paper #18-06036

TRIS, TRB, ATRI

Jan 8 2018 11:33AM