Full-depth reclamation (FDR) mix design: Proposed revisions to the indirect tensile strength thresholds

Abstract Full depth reclamation (FDR) is a cost-effective recycling strategy that reuses both asphalt bound materials and unbound granular materials to refurbish existing pavement subsurface layers. In this study, the effect of sample size, conditioning procedure, and testing temperature on the indirect tensile (IDT) strength of FDR mixtures was evaluated. Test results indicated that all 6-inch diameter samples had lower IDT strength as compared to the 4-inch diameter samples, regardless of the material source, binder type, binder content, or conditioning procedure. Revised IDT acceptance criteria were proposed for the Texas Department of Transportation (TxDOT), and recommendations on testing temperature were also provided.