Toward Non-Petroleum-Derived Asphalt Mixes: Using Biobinders for High-Modulus Asphalt Mixes with High Reclaimed Asphalt Content

The concept of biobinders has been recently developed to refer to binders for asphalt mixtures that contain any bio-renewable materials. In this sense, there exist different types of biobinders with diverse natures and their use is still not wide spread also due to the uncertainties about their performance. Therefore, as a first step, every biobinder should be characterized to provide confidence for its use. Secondly, a way to increase the use and acceptance of biobinders is to use these biobinders in Reclaimed Asphalt (RA) mixtures replacing the need for petroleum-derived bituminous binders. In this manner, asphalt mixtures performance can benefit from the bitumen already present in RA while the use of new bitumen is avoided. Within this framework, this paper shows: (1) the characterization of two biobinders to be used as fresh binders in high-RA content mixtures; (2) their blend design with a aged RA binder to assess the feasibility of producing high- RA content mixtures; (3) biobinders and RA blends’ rheological evaluation; and (4) the rheological characterization of 50% RA mixtures manufactured with the biobinders. The results show the importance of performing a blend design before high content RA asphalt mixtures manufacturing as well as the suitability of biobinders to be used as fresh binders in recycled asphalt mixtures.