The Association of Modified Asphalt Producers (AMAP), a St. Louis-based international association dedicated to the development, production and use of modified asphalts that extend the life of interstate pavements, announced that it has provided $17,000 to the Affiliate Committee of the Asphalt Institute to help fund the organization's latest study which is focused on the determination of specific calibration factors for polymer-modified asphalts (PMA). The latest study comes as a follow-up to an initial study (Engineering Report ER-215) conducted by AMAP and the Asphalt Institute. The original study, published in 2005, setting out to quantify the effects of polymer-modified asphalts on reducing pavement distress, proved that PMA reduced pavement distress and extended the service life of flexible pavements and overlays but did not determine specific calibration factors for PMA mixtures. Currently, the road-building guidelines which have been set by the federal government are based on global calibration factors which were determined for conventional, unmodified asphalts. Because of this, the Asphalt Institute is concerned that the use of global calibration factors could overestimate the amount of stress placed on polymer-modified asphalt layers. The new study aims to determine the calibration factors specifically for PMA mixtures in order to reduce the bias and error between distress predictions. The study, which got under way in December 2006, is being conducted by independent researcher Harold Von Quintus of Round Rock, Texas-based Applied Research Associates Inc. Estimated completion time for the study is six months at a total cost of $37,000. In addition to funds that AMAP provided, the Federal Highway Administration has furnished $15,000, with the remaining $5,000 coming from five polymer manufacturers supplying the U.S. market. For more information on the Association of Modified Asphalt Producers, or the organization's involvement in the Asphalt Institute study, contact Bob Berkley at (314) 843-2627.
Staff | September 28, 2010