Determination of the performance and damage to asphalt of bio-sourced asphalt release agents (ARAs) Part II: evaluation of biodegradable products for use as ARAs and bitumen removers (BRs)

Abstract

Asphalt release agents (ARAs) are used for reducing the adherence of asphalt residue to tools used for asphalt mix production, while bitumen removers (BRs) are used for cleaning the asphalt residue from the tools after their use. In order to be able to formulate well performing and safe bio-based ARAs and BRs, the performance, safety and chemistry of the currently available bio-degradable ARAs and BRs from both French and American construction industry were analysed. This provided insight into how ARAs and BRs functioned, insight that is as of now, not available. In addition to these, biodegradable short-chain esters were also tested. The testing of the damage to asphalt pavement by ARAs and BRs and of the quantification of their performance, were developed in Part I of this article. In this paper, gas chromatography examined the chemical composition of the agents while Fourier transformed infrared spectrometry was used to chemically investigate the agents’ chemical modification of the bitumen. It was found that commercial ARAs can be classified by their functioning as either surfactants or softeners. Additionally, it was found that short-chained esters are very effective as BRs.