Enhancing the Fundamental Knowledge and Use of Asphalt Emulsions Using Systematic Scientific and Engineering Approaches TR-708C, August 2018

(2018) Enhancing the Fundamental Knowledge and Use of Asphalt Emulsions Using Systematic Scientific and Engineering Approaches TR-708C, August 2018. Transportation, Department of

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Abstract

Due to their lower application temperature, lower energy consumption, and lower viscosity, asphalt emulsions are gaining popularity in the United States and worldwide. About 3 million tons of asphalt emulsion are produced in the US, which accounts for 5% to 10% of the total asphalt consumption. However, there is still a lack of understanding of the mechanisms by which asphalt emulsions are produced and how they work. This report reviews current literature available on asphalt emulsions to determine the present state of the practice, documents the development of an asphalt laboratory at Iowa State University, reports asphalt emulsion results, and creates an action plan for future work. Two standard emulsions, one non-modified and one polymer-modified, were produced in the laboratory using a state-of-the-art laboratory-scale asphalt emulsion mill, emulsion properties were compared and experience was gained. To determine standards by which to compare emulsions to the performance grade (PG) system of binder classification, master curves of elastic modulus (G*) were plotted between emulsion residue and their base binders. The elastic recovery of polymer-modified asphalt emulsion residue was also tested to compare its performance with polymer-modified binders. Finally, sweep tests were conducted on laboratory-prepared chip seal samples to compare the aggregate mass lost between samples prepared with asphalt emulsion and hot applied asphalt.