Recycled bio-sourced glycerol and diglycerol for asphalt release agents (ARA)

Abstract

The objective of this study is to develop bio-sourced waste chemicals for use as asphalt release agents. Glycerol was extracted from bio-sourced waste and transformed by transesterification into the surfactants undecenoates of glycerol (MUG) and undecenoates of diglycerol (MUDG). They were composed of glycerol, monoglycerol, diglycerol, triglycerol, tetraglycerol and water. The formulations were mixed separately with water at quantities of 5–50%, along with acetone and commercial bio-sourced ARAs in order to observe the effects. The formulations were subjected to performance testing with the asphalt slide test, finding significant reduction in adhesion for a number of different formulations. The interaction of the formulations with bitumen was tested by the bitumen degradation test, which was combined with FTIR–ATR analysis, finding that the formulations do not dissolve the bitumen, but rather were adsorbed by the bitumen. The effects on asphalt mix of the best performing formulation, MUG at 20% in water, was tested by indirect tensile strength, determining that the formulation was acceptable for use in the field.

Keywords:

• asphalt release agents
• asphalt testing
• bio-sourced
• FTIR analysis
• glycerol
• undecylenic acid

Acknowlegments

The authors would like to thank FUI (French Designated Inter-Ministry Fund) and the AGRIBTP research project (www.agribtp.fr) (BPI France – Région Midi-Pyrénées) for their financial support as well as Kemerid (France, www.kemerid.com) for their technical support.