ORIGINAL PAPER Laboratory Comparison of Crushed Aggregate and Recycled Pavement Material With and Without High Carbon Fly Ash Haifang Wen • Justin Warner • Tuncer Edil • Gingan Wang Received: 22 May 2008 / Accepted: 30 December 2009 / Published online: 7 January 2010 Ó Springer Science+Business Media B.V. 2010 Abstract In-place recycling of asphalt pavement materials is a sustainable rehabilitation method. Existing hot-mix asphalt (HMA) layer is pulverized and blended with some or the entire base course and possibly some subgrade to form a broadly graded material referred to as recycled pavement material (RPM). The RPM is then compacted as the new base course and overlaid by a new layer of HMA. In some occasions, additives are added to increase the strength of RPM base course, such as cement, emulsion, fly ash. It is plausible to utilize high calcium high carbon fly ash, as the high level of carbon prevents fly ash from being used in concrete. A series of laboratory tests were conducted to evaluate the performance of these materials, including crushed aggregate, untreated RPM, and treated RPM with high carbon fly ash. The tests included compaction, California Bearing Ratio, resilient modulus, and unconfined compressive strength for treated RPM. The engineer- ing properties of these materials were compared. Keywords High carbon fly ash  Recycled pavement materials  Crushed aggregate  Resilient modulus  CBR  Compressive strength 1 Introduction In-place recycling of asphalt pavement materials is a sustainable rehabilitation method. Existing hot-mix asphalt (HMA) layer is pulverized and blended with some or the entire base course and possibly some subgrade to form a broadly graded material referred to as recycled pavement material (RPM). The RPM is then compacted as the new base course and overlaid by a new layer of hot mix asphalt (HMA). In some occasion, additives are added to increase the strength of RPM base course, such as cement, emulsion, fly ash. Wen et al. studied the field performance of Class C fly ash stabilized RPM in Wisconsin and concluded that it was a feasible technology (Wen et al. 2004). Edil et al. also studied the feasibility of this technology in Minnesota (Lin et al. 2007). Class C H. Wen (&)  G. Wang Department of Civil and Environmental Engineering, Washington State University, PO Box 642910, Spokane Street, Sloan Hall 35, Pullman, WA 99164-2910, USA e-mail: haifang_wen@wsu.edu J. Warner Department of Civil and Environmental Engineering, University of Wisconsin at Madison, 1221 Engineering Hall, 1415 Engineering Drive, Madison, WI 53706-1691, USA e-mail: jwarner@wisc.edu T. Edil Department of Civil and Environmental Engineering, University of Wisconsin at Madison, 2228 Engineering Hall, 1415 Engineering Drive, Madison, WI 53706-1691, USA e-mail: edil@engr.wisc.edu 123 Geotech Geol Eng (2010) 28:405–411 DOI 10.1007/s10706-009-9300-1