Factors Affecting Rigid Pavement Performance: Evaluation of the LTPP SPS-2 Experiment

The Long Term Pavement Performance (LTPP) Specific Pavement Study Experiment 2 (SPS-2), Strategic Study of Structural Factors for Jointed Plain Concrete Pavements (JPCP), is one of the key experiments of the LTPP program. The main objective of this experiment is to determine the relative influence and long-term effectiveness of JPCP design features (including slab thickness, PCC flexural strength, base type and drainage, and slab width) and site conditions on performance. It is expected that the successful completion of the SPS-2 experiment will lead to improvements in design procedures and standards for construction of jointed plain concrete pavements. These improvements will contribute to achieving the overall goal of the LTPP program—increased pavement life and better utilization of resources. This paper presents the key findings from a recently completed FHWA study that was the first-time comprehensive review and evaluation of the SPS-2 experiment. The results presented herein will be useful to both pavement researchers and practitioners for improving pavement design and management decisions, and for calibration and validation of mechanistic-empirical design models including the 2002 Design Guide models.