The objective of this award is to understand the foaming process using several foaming agents to guide us in the design of a new warm mix asphalt (WMA) technology. In the proposed project, researchers from Columbia University and Michigan Technological University will investigate three foaming agents as potential candidates, including soda as a chemical foaming agent, CO2/N2 gas and ethanol as physical blowing agents. Multiphase characterization and viscoelastic modeling studies will be conducted to investigate how the microstructure of asphalt materials evolves with time, temperatures, and proportion of material constituents, and in doing so study any differences and relative benefits from chemical vs. physical blowing agents. A single or the combination of foaming agents will be determined for optimal end-results. The fatigue strength, the long-term performance and life cycle cost of the WMA based on the foaming process will be characterized with accelerated test methods.
This project integrates state-of-the-art rheological and accelerated aging tests, thermodynamics, poromechanics, chemical changes and multi-scale modeling to identify the physical and mechanical properties of foamed asphalt materials. The proposed studies will advance the understanding of the foaming process and establish a theoretical framework to predict the material behavior for material design, which will lead to new theories and models of sustainable engineering materials in energy and environmental aspects. This project provides a unique opportunity for conducting interdisciplinary research in sustainable engineering to reduce energy consumption, greenhouse gas emission, to facilitate recycling of asphalt materials, and improve life-cycle performance. The technologies developed in this program will be rapidly transferred to industry.
