University of California Pavement Research Center

This technical memorandum evaluates the half-life performance of three long-life jointed plain concrete pavements (JPCPs), a combined total of 260 lane-miles, that were built in Southern California in the early 2000s. The pavements were designed for a 40-year life, which was twice the standard 20-year design life used for JPCP at that time. The projects are located in or close to the Mojave Desert on heavily trafficked interstate highways with 2022 annual average daily truck traffic levels between 2,800 to 5,100. The performance of the pavements has been evaluated based on data from the Caltrans pavement management system (PMS) databases (with software system PaveM), including pavement condition surveys with data about lane-based cracking, transverse joint faulting, and smoothness data, and the as-built database that includes all maintenance, rehabilitation, and reconstruction activities conducted on the Caltrans road network. The PMS databases were complemented with an in-situ evaluation of the projects in 2022 that included an inertial profiler evaluation and a road closure of one mile per project for visual inspection, coring, and falling wight deflectometer testing. Overall, the performance of the projects has been excellent so far. The third-stage cracking (slabs with two or more cracks) is essentially zero in all lanes, the faulting is also essentially zero, and the smoothness as measured by the International Roughness Index has been stable since the construction of the projects. The load transfer efficiency of the doweled transverse joints was high, from 80% to 85%, and it was also very uniform along the sections, with minimal diurnal variation (morning versus afternoon). Mechanistic-empirical modeling with AASHTOWare Pavement ME Design (version 2.5.5) supports the excellent performance of the projects and the lack of transverse cracking, in particular. Further, none the JPCP long-life projects has required any maintenance or rehabilitation activity (e.g., individual slab replacement or grinding) since their construction. The only concern with the performance of the projects is the presence of longitudinal cracking, affecting to 4% to 7% of the slabs, in some truck lanes. The longitudinal cracking may be related to the dry environment and, potentially, the use of widened slabs in one of the projects.