Performance Evaluation of a Hot-Mixed Recycled Bituminous Pavement, Route 4, Burlington. Final Report

摘要

In June 1980, a 0.71-mile section of a longer reconstruction of Rt 4 in Burlington was reserved as a testbed for hot-mix asphalt concrete recycling project. The observation sections included a full-depth recycled portion, a full-depth conventional asphalt pavement serving as a control, a 2 1/2-inch recycled overlay, and a 2 1/2-inch conventional overlay control. The recycled material is a blend of 30% milled material and 70% virgin aggregate. Testing was initiated in October 1980 and consisted of condition surveys, friction tests, photologging, roughness measurements, transverse-surface profiles and extraction tests on cores. Distress on the full-depth sections consisted almost entirely of longitudinal cracking, initiating approximately 1 1/2 years after placement, with a rapid increase beginning in 1985. As of September 1986, friction numbers on all sections show a strong seasonal variation and are marginal. Roughness is low and no rutting has been detected. Extraction tests show that asphalt viscosities are higher on the recycled than on the control. Past research by others suggests that rapid aging may be inherent with recycled asphalts.