Transfer of RAP binder and its influence on recycled HMA under three mixing techniques

Abstract

This study aims to identify the difference in the mobilisation degree of RAP asphalt binder under three mixing techniques and its influences on the performance of recycled hot-mix asphalt mixture (HMA). Glass beads were selected to replace parts of fresh coarse aggregates, and to analyze the transfer of RAP binder using Fourier Transformation Infrared (FTIR) spectroscope analysis. Superpave Gyratory Compactor (SGC) and Hamburg Wheel-Track Device (HWTD) were used to evaluate the compaction property and the high-temperature performance of recycled HMA. Results showed that the relative percentage of reclaimed asphalt recovered (Rp) varied with the mixing techniques. The workability of recycled HMA is related to the mixing technique. The softer fresh asphalt binder is more capable of facilitating the mineral aggregates to form a stable skeleton structure. In addition, the transfer of RAP binder in recycled HMA may be an important factor influencing the skeleton structure.

KEYWORDS:

• Recycled HMA
• mixing technique
• FTIR
• compaction property
• high-temperature performance

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ contributions

Conceptualisation, Y.L. and C.Z.; methodology, Y.L. and X.N.; data analysis, G.C. and J.G.; writing – original draft preparation, Y.L.; writing – review and editing, X.N. and Y.G.

Additional information

Funding

This work was supported by the department of education of Hubei province under Grant [Z2021239/Q20211208].