Application of the Bailey Method to NH Asphalt Mixtures
Record Type: DOT
The Superpave mix design system provides guidance in selecting the appropriate component materials for asphalt concrete mixtures. The Superpave binder and aggregate property specifications are currently being implemented by agencies as part of the Superpave volumetric mix design method. However, the selection of the design aggregate structure is left to the experience of the mix designer. It is important to understand the influence of the aggregate structure on the volumetric properties, construction, and performance of the asphalt mixture to achieve the desired properties and performance. The Bailey Method provides a systematic approach to blending aggregates to meet the Superpave volumetric criteria based on the concepts of aggregate interlock and aggregate packing. In addition, the Bailey method provides tools for evaluating the effect of aggregate structure on mixture properties, constructability, and performance. The proposed research will evaluate three existing New Hampshire mixes using the Bailey Method. In addition, the influence of aggregate shape/texture (100% fractured aggregate versus gravel stone aggregate) and the addition of RAP on the aggregate structure and performance will be investigated for the three mixtures. The results of this research will provide a better understanding of the relationship between aggregate structure and the volumetric properties, ease of construction, and performance of typical NH mixtures. Use of the Bailey Method will ensure coarse aggregate interlock and control of aggregate packing, allowing the designer to specify desired mixture properties. This will eliminate the normal trial and error process used in determining the design aggregate structure and will help in the transition to contractor mix design. The evaluation tools in the Bailey Method can also be used for quality control during the construction process. The proper changes to the production process can be made to meet the quality requirements in the field as a result of the understanding of the effects of aggregate structure on the properties of the asphalt mixture.
Start date: 2002/1/1
Status: Completed
Contract/Grant Number: 13733F
Total Dollars: 140000
Source Organization: New Hampshire Department of Transportation
Date Added: 04/23/2003
Index Terms: Superpave, Asphalt mixtures, Asphalt concrete, Mix design, Volumetric analysis, Aggregate mixtures, Performance evaluations, Research projects,
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