Full Depth Reclamation (FDR) for Suburban/Urban and Local Roads Application

Project summary:

Full-depth reclamation (FDR) is a rehabilitation method that improves the service life of pavement structures by reusing asphalt materials, thereby reducing costs and allowing for conservation of nonrenewable resources. However, the lack of mechanics-based material testing procedures and performance-based specifications limit the use of FDR processes. First, this study presented the FDR design and construction process. A literature review focusing on FDR research was then completed, and a survey was conducted to obtain relevant information regarding current FDR practices in Minnesota. Next, an Indirect Tensile Test (IDT) and Dynamic Modulus Test in IDT mode testing was performed on four FDR materials: field mixed, lab compacted; lab mixed, lab compacted; FDR with cement additive; and FDR with graphene nanoplatelet (GNP) additive. Two curing times were used to determine how physical properties change over time. Test results were used to perform simulations in MnPAVE software and a Life Cycle Cost Analysis (LCCA). Laboratory observations indicated that cement additive reduces predicted life and increases critical cracking temperature with a slight increase in cost; GNP additive reduces predicted life but also reduces critical cracking temperature with a significant cost increase; lab mixed samples performed better than field mixed, suggesting that field methods could be improved; and curing has a positive effect on the FDR materials with cement and GNP additives (for both materials, the dynamic modulus increased and the GNP samples had a slight increase in tensile strength). MnPAVE simulations and LCCA results indicated that over a 35-year period, FDR may be a more cost-effective method than traditional mill and overlay.