Evaluation of Laboratory and Field Performance of Cold In-Place Recycling (CIR) Asphalt Mixtures

The objective of this research study is to evaluate both laboratory and field performance of Cold In-Place Recycling (CIR) asphalt mixtures in terms of rutting and cracking resistance. A balanced CIR mixture prepared with foamed asphalt at 2.5% foaming water was selected to construct three full-scale CIR sections at Rowan University’s Accelerated Pavement Testing Facility (RUAPTF): (1) a rut-resistant section (i.e., containing 2% binder content), (2) a crack-resistant section (i.e., containing 4% binder content), and (3) a performance-based section (i.e., containing 3% binder content). Once cured, one inch Hot Mix Asphalt (HMA) was placed on top of the CIR Layer. An accelerated pavement testing (APT) was then performed on each section using Dynatest Mark IV Heavy Vehicle Simulator (HVS) to apply repeated truck tire loading magnitudes for 150,000 passes. Pavement mechanistic responses were recorded by asphalt strain gauges, pressure cells, and thermocouples embedded at the bottom of each CIR layer. Rutting and cracking performance of each section was assessed and compared to the laboratory performance of foamed asphalt CIR mixtures compacted with 30 gyrations and subjected to a three-day curing at 10 °C. The results showed that the rut-resistant section presented lower rutting susceptibility, while all three section showed a similar cracking resistance under accelerated truck loading.