Warm-Mix Asphalt Pilot Project in Connecticut

Abstract

This paper presents the details on the first official state warm-mix asphalt (WMA) pavement project in Connecticut. The construction took place between July 20 and July 22, 2010, and it involved three experimental sections: a control section with a conventional hot-mix asphalt (HMA) and two WMA sections that used wax and foamed asphalt. All three sections are located on Route 70 in central Connecticut. Each section is approximately 1 km long and includes lanes in both directions. The construction was done as a 50-mm overlay with 12.5-mm Superpave® mix. Each mix was sampled over a 3-day construction period for further evaluation in the laboratory. The materials were collected in loose form and reheated and compacted under laboratory conditions (laboratory-fabricated specimens). This paper discusses the effect of mixture type as shown by the results from several tests conducted in the laboratory, including the semicircular bending test, the Hamburg wheel tracking test, the indirect tensile test, and the disk-shaped compact tension test. The results from the WMA specimens were also compared with conventional HMA specimens. Finally, the paper presents the performance data from all three test sections after the first winter season and correlates these observations with the laboratory results.