01661026

Component

Virgin binder selection is one of the critical design steps for asphalt mixtures. The binder blending chart is used as the current practice of virgin binder selection for asphalt mixtures that contain more than 25 percent reclaimed asphalt pavement (RAP). However, this practice may not account for the true blending that occurs within a RAP mixture. This study aims to develop a mixture blending chart based on the dynamic modulus values of RAP mixtures, which can be used to select virgin binder and better control the performance of high percentages RAP mixtures. Three sets of RAP mixtures were evaluated. Two blending models based on the rule of mixtures, including Voigt model and Reuss model, were examined to develop the mixture blending chart. Based on the results of both indirect tensile and axial dynamic modulus tests in this study, the Reuss model, which specifies the lower bound of the blended modulus of a RAP mixture, is found to be more appropriate than the Voigt model to be used as the mixture blending chart for a RAP mixture. The Voigt model overestimated the modulus values of the RAP mixtures and can lead to the selection of an unexpected softer virgin binder when more than 25 percent RAP is incorporated. The developed mixture blending chart was further verified using the finite element analysis that was conducted on the constructed ideal binary-blended RAP mixtures.

This paper was sponsored by TRB committee AFK30 Standing Committee on Non-Binder Components of Asphalt Mixtures.

18-01723

English

5p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References

Asphalt mixtures; Blending; Dynamic modulus of elasticity; Reclaimed asphalt pavements

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2018 Paper #18-01723

TRIS, TRB, ATRI

Jan 8 2018 10:26AM