This research focused on the development of fatigue-based payment adjustment factors for use in performance-related specifications for full-depth asphalt pavements. A rational method of adjusting a contractor's payment as a function of the quality of the product is an essential element of a performance related specification (PRS). The Quality Control/Quality Assurance (QC/QA) specifications and practices in the highway industry for the construction of asphalt pavements were reviewed. The survey indicated that many hybrids of method related and end result specifications are being used by the states. Currently, no state is known to be utilizing a PRS for full-depth pavements. Details of the QC/QA program, testing and sampling frequencies, and payment adjustment schedules are presented. A review of extant performance prediction models indicated that additional research in developing quantifiable relationships between the key distresses in an AC pavement and contractor controlled material and construction (M&C) variables is necessary before a comprehensive PRS can be developed. However, satisfactory secondary relationships between the M&C variables (air voids, asphalt content, fines content and thickness) and fatigue cracking, a major structural distress, were identified. Fatigue failure is thought to be influenced not only by the mean values of the M&C factors but also by their variability. A computer simulation program was developed to examine the effect of deviations from target quality levels. The economic consequence of these deviations was examined by using a life-cycle costs strategy that included maintenance and user operating costs. A rational payment adjustment schedule was defined as one that would provide a mechanism by which pay adjustments could be established that would reflect the economic impact of contractor nonconformance to target quality levels. The pay factors developed are a function of the percent change in the anticipated present worth of the life-cycle costs of the as-constructed pavement compared to the as-designed pavement.

This volume highlights the latest advances, innovations, and applications in the field of asphalt pavement technology, as presented by leading international researchers and engineers at the 5th International Symposium on Asphalt Pavements & Environment (ISAP 2019 APE Symposium), held in Padua, Italy on September 11-13, 2019. It covers a diverse range of topics concerning materials and technologies for asphalt pavements, designed for sustainability and environmental compatibility: sustainable pavement materials, marginal materials for asphalt pavements, pavement structures, testing methods and performance, maintenance and management methods, urban heat island mitigation, energy harvesting, and Life Cycle Assessment. The contributions, which were selected by means of a rigorous international peer-review process, present a wealth of exciting ideas that will open novel research directions and foster multidisciplinary collaboration among different specialists.

Design related project level pavement management - Economic evaluation of alternative pavement design strategies - Reliability / - Pavement design procedures for new construction or reconstruction : Design requirements - Highway pavement structural design - Low-volume road design / - Pavement design procedures for rehabilitation of existing pavements : Rehabilitation concepts - Guides for field data collection - Rehabilitation methods other than overlay - Rehabilitation methods with overlays / - Mechanistic-empirical design procedures.