WASHINGTON-Commissioned by the Federal Highway Administration and backed by funding from 32 states, Oregon State University has begun a five-year study of crumb-rubber-modified asphalt, its technologies and applications. ``Our goal is to identify whether rubberized asphalt is cost-effective and sound from an engineering standpoint,'' said Rita Leahy, a visiting assistant professor of civil engineering at Oregon State who is participating in the project.
Researchers also will identify the applications in which asphalt rubber is particularly effective, and present information which offers guidance to states in structural and mix design, according to Ms. Leahy. Results of the FHWA study will be presented to Congress.
The FHWA commissioned the study under Section 1038 of the Intermodal Surface Transportation Efficiency Act, which was designed to promote the use of rubberized asphalt in federally funded state highway projects. Funding for the study is slightly more than $1 million, according to the agency.
Many states, unfamiliar with rubberized asphalt and balking at its relatively high cost, have fought-so far successfully-to waylay Section 1038.
In this light, it seems ironic that so many states would fund a study to promote rubberized asphalt. But the states hope the study will show the folly of Section 1038's percentage requirements for rubberized asphalt use, said a source close to the project who asked not to be identified.
``Highway engineers don't want Congress telling them which materials to use,'' he said. ``The choice of any material we use should be based on its engineering characteristics. This study is to help us decide how and when to use this material.
``We would be fighting Congress tooth and nail with any other material they tried to force us to use,'' he added. ``Would you want Congress telling a surgeon how to perform your surgery?''
Beginning the project last September, the Oregon State researchers have set up an ``Expert Task Group'' or ETG-consisting of state transportation officials, industry representatives and materials suppliers-to develop construction, structural design and mix design guidelines based on the data generated from the research.
The researchers have visited Florida and Arizona, two states with wide experience in using rubberized asphalt, to confer with state officials, highway construction firms and rubberized asphalt manufacturers. They plan to visit California, which also uses rubberized asphalt widely, in March.
Later the study will involve field experiments across the U.S., with rubberized asphalt pavement installed in various terrain and climates using different mixes, technologies and designs.
Concurrently with this study, three federal agencies are monitoring various road construction sites to determine the possible health effects of asphalt rubber fumes on workers.