This study has four objectives: 1) Determine the effects of fuel type, fuel quality, and combustion conditions on the physical and chemical properties of asphalt concrete produced in Hot Mix Asphalt (HMA) plants; 2) Assess the potential effects of the physical and chemical properties induced by fuel type, fuel quality, and combustion conditions on field performance and constructability of asphalt concrete; 3) Recommend specifications for fuel type, fuel quality, and combustion conditions that ensure acceptable asphalt concrete performance; 4) Develop or recommend test methods that field personnel can easily use to ensure compliance with the recommended specifications.

This research was initiated to investigate the effects of differing fuel types and combustion conditions on hot mix asphalt. In early October, 2001, eleven fuels were used to fire a plant under optimum, insufficient oxygen and excess oxygen conditions. Samples of heated aggregates, mixtures and raw materials (fuels, binder and aggregates) were obtained and transported to West Lafayette, Indiana, for eventual testing. While all of the samples have been obtained, no testing has been done yet pending a decision on which test methods would provide the best information to meet the objectives. As discussed in detail in this report, we are seeking the approval of the technical panel to commence testing. Chromatography can begin as soon as the panel concurs. After the holidays, binder and mixture physical testing can begin on the control samples and some insufficient oxygen cases. Although the project is slightly behind schedule, it should be quite easy to catch up. 2/19/02