Non Technical Summary
Asphalt concrete is a greenhouse gas intensive material which is used to surface more than 94% of paved roads in the United States. One of the critical issues currently faced by the asphalt industry is producing more sustainable materials, of which bioproducts can serve as one option. This project seeks to use biochar derived from waste timber via mass pyrolysis and other biomass treatment processesin asphalt concrete mixes, to both lower the greenhouse gas footprint of asphalt mixtures and reduce harmful emissions during production and construction of asphalt pavements. This project will evaluate the use of biochar from the perspective of performance of asphalt materails and preservation treatments which use it compared to those currently used in roadway systems, as well as economic and environmental analysis to determine how feasible replacement with biochar of fine aggregate is. Finally, the project will involve a framework for full-scale testing for acceleration of this technology to use in practice.

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
403	0650	2020	85%
141	0410	2000	15%

Knowledge Area
403 - Waste Disposal, Recycling, and Reuse; 141 - Air Resource Protection and Management;

Subject Of Investigation
0650 - Wood and wood products; 0410 - Air;

Field Of Science
2020 - Engineering; 2000 - Chemistry;

Goals / Objectives
This projectseeks to use biochar derived from waste timber via mass pyrolysis in asphalt concrete mixes, to both lower the greenhouse gas footprint of asphalt mixtures and reduce harmful emissions during production and construction of asphalt pavements. This research project's goals includelaboratory evaluation of the biochar itself, the biochar-modified asphalt, and asphalt mixtures with biochar including performance (rheological, chemical, and mechanical) and laboratory emission analysis. Life cycle cost assessment and life cycle assessment are both included in the analysis as well. In addition to using these tools to assess the potential use of biochar in asphalt mixtures and preservation treatments, this project's goals includedevelopment of preliminary materials towards a "Bioproducts in Civil Engineering" courseand development of a framework for full-scale accelerated pavement testing of asphalt concrete with biochar to prove viability and feasibility of using this material nationwide.

Project Methods
Methods:Evaluation of biochar size distribution using dynamic light scattering particle size analysis and sieve analysis (evaluation metrics will be established)Characterization of volatile organic compound emissions from asphalt materials using mass spectroscopy (evaluation metrics wil be established)Asphalt performance grading and mix design, as well as performance testing using AASHTO standards (evaluation metrics are standardized and well known; good performance will be indicated by achieving at least similar performance to conventioanl materials)Pavement preservation treatment standard and novel testing methods in lab (evaluation metrics will be established; good performance will be indicated by achieving at least similar performance to conventioanl materials)FHWA LCCA and LCA tools for sustainability and cost assessment (evaluation will consist of comparison with conventional materials)