Partial replacement of asphalt binder with bio-binder: Characterisation and modification

This paper introduces bio-binder as a partial replacement for bituminous binder on highway and airport pavements. The proposed bio-binder is produced from the thermochemical conversion of swine manure. Bio-binder is then blended with virgin binder to produce bio-modified binder (BMB). In addition to being a renewable alternative for petroleum-based binder, the production and application of bio-binder may provide a solution for the management of swine manure waste. Furthermore, the application of bio-binder will improve asphalt binder\u27s properties while reducing asphalt pavements\u27 construction cost; the cost of bio-binder production is $0.54/gallon compared with that of asphalt binder $2/gallon. However, although the BMB has improved low-temperature properties, it may decrease the high-temperature grade of the binder. To address this concern, we in this paper investigate the feasibility of applying polyphosphoric acid into BMB. Using BMB in asphalt pavements can reduce mixing and compaction temperatures and ageing and stiffening characteristics of the reclaimed asphalt pavements (RAPs) and virgin binders. © 2012 Copyright Taylor and Francis Group, LLC