The Association of Modified Asphalt Producers (AMAP), a St. Louis-based international association dedicated to the development, production and use of modified asphalts that greatly 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 was published in 2005 and set out to quantify the effects of PMA on reducing pavement distress. The initial study 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 that 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 PMA 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.
"We're pleased to help fund this important study because it has the power to determine calibration factors that reflect the benefits of polymer-modified asphalt," said Bob Berkley, executive director of AMAP. "By utilizing these PMA factors, state highway engineers will get an accurate estimate of roadway distress response that we are confident will demonstrate the extended highway life-cycle that polymer-modified asphalts can provide."
The study, which got underway in December 2006, is being conducted by independent-researcher Harold Von Quintus of Round Rock, Tex.,-based Applied Research Associates Inc. Estimated completion time for the study is six months, at a total cost of $37,000.
In addition to the $17,000 in funds that AMAP has provided for the study, the Federal Highway Administration has furnished $15,000, with the remaining $5,000 coming from five U.S.-based polymer-producing companies.
