The California Warm-Mix Asphalt Demonstration Project

摘要

The scene: It's 57 degrees Fahrenheit and foggy on the afternoon of May 7, 2008 on Highway 1 near Morro Bay, California. The contractor, R. Burke Corp., is paving an open-graded friction course (OGFC for short) overlay using a PG 58-34 PM (polymer-modified) binder. The mat thickness is 1.2 inches, and the OGFC has a nominal maximum aggregate size of 0.5 inch. The open-graded friction course is being produced by Union Asphalt Inc. at a batch plant 25 miles from the paving site. This results in a 30- to 45-minute haul time. Between the haul time, the thinness of the overlay, and the damp, cool weather, paving conditions are less than ideal. This particular day also brings an unusual level of scrutiny: More than 125 representatives of various state Departments of Transportation, California local agencies, energy companies, asphalt concrete suppliers, warm-mix asphalt technology providers, and contractors are watching this paving job with keen interest. The occasion is the first warm-mix asphalt open house sponsored by the California Department of Transportation, more commonly known as Caltrans.