Field evaluation of porous asphalt course for life-cycle cost analysis

Porous asphalt courses (PAC) provide environmental and safety benefits by reducing traffic noise and improving drainability. As pressure increases on the cost and availability of natural resources, a greater understanding is needed of field performance to allow maintenance and preservation of resilient, sustainable and economic networks. The main purpose of this paper is to utilize life-cycle cost analysis (LCCA) as a decision-support tool for three pavement rehabilitation strategies. These alternatives included open-graded friction course using natural aggregate (OGFC), porous asphalt course using natural aggregate (PAC), and porous asphalt course using steel slag (SS-PAC). The LCCA followed the Federal Highway Administration's RealCost procedure and incorporated information collected from highway agencies. Based on the results of the performance analysis, pavement life-cycle models were developed for each alternative. Using the life-cycle models and historical unit costs, deterministic and probabilistic LCCAs were conducted. The results demonstrated the cost saving of SS-PAC in both low and medium price ranges. In order to have economic benefits, the service life of SS-PAC needed to be more than eight years for a high price range. SS-PAC had a 78 and 92 percent chance of being more cost-effective than OGFC and PAC according statistical analysis, respectively. Conclusions from the LCCA supported use of the SS-PAC alternative since SS-PAC was shown to be relatively cost-effective over the 40-year analysis period. Utilization of the SS-PAC alternative would combine cost efficiency and sustainability for highway projects, especially rehabilitation and reconstruction.