Field Assessment of Cold In-Place Recycled Asphalt Mixtures Using Accelerated Pavement Testing

Abstract

The objective of this study was to assess the performance of full-scale cold in-place recycled (CIR) asphalt sections using accelerated pavement testing (APT). A balanced mix design approach was followed to optimize the binder contents of CIR mixtures, and these mixtures were subsequently used to construct three full-scale sections (7.6 by 3.7 m) at Rowan University’s Accelerated Pavement Testing Facility. Foamed asphalt was added in varied contents: 2%, 3%, and 4% by total mix weight. All CIR mixtures were prepared at a constant water content of 3%. Each full-scale section was instrumented with asphalt strain gauges, pressure cells, and thermocouples to evaluate the structural responses within each section. A heavy vehicle simulator (HVS) was utilized to apply accelerated loading on each full-scale pavement section. A truck tire was utilized to apply a 40-kN load while an aircraft tire was utilized to apply a 100-kN load. As accelerated loading was applied, a number of field tests and visual inspections were performed to determine (1) permanent deformation using a surface profiler, (2) the structural integrity using a heavy weight deflectometer before and after APT, and (3) cracking potential by assessing stress and strain responses. The results showed that the CIR section with 2% binder content presented the best rutting performance under truck loading and the highest rutting susceptibility under aircraft loading. Conversely, the CIR section with 3% binder content presented the highest cracking resistance under accelerated truck and aircraft loading.