PURPOSES : Long-life asphalt pavements are used widely in developed countries. In order to be able to devise an effective maintenance strategy for such pavements, in this study, we evaluated the performance of the long-life asphalt pavements constructed along the national highways in South Korea. Further, an economic evaluation of the long-life asphalt pavements was performed based on a life-cycle cost analysis. We aimed to devise a model for evaluating the performance of long-life asphalt pavements using the national highway pavement management system (PMS) database as well as for analyzing the economic feasibility of such pavements, in order to promote their use in South Korea.
METHODS : The maintenance history and pavement performance data were obtained from the national highway PMS database. The pavement performances for a total of 292 sections of 10 lanes (5 northbound lanes and 5 eastbound lanes) of national highways were used in this study. Models to predict the performances of hot mix asphalt (HMA) and long-life asphalt pavements under two distinct traffic conditions were developed using a simple regression method. Further, the economic feasibility of long-life asphalt pavements was evaluated using the Korea Pavement Management System (KoPMS).
RESULTS : We developed service-life prediction models based on the traffic volume and the equivalent of single-axle load and found that long-life asphalt pavements have service lives 50% longer than those of HMA pavements. Further, the results of the economic analysis showed that long-life asphalt pavements are superior in terms of various economic indexes, including user cost, delay cost, total cost, and user benefits, even though their maintenance cost is higher than that of HMA pavements. A comparison of the economic feasibilities of the various groups showed that group A is superior to HMA pavements in all aspects except in terms of the maintenance criterion (crack 20% or higher) as per the NPV index. However, the long-life asphalt pavements in group B were superior in terms of the maintenance criterion (crack 25% or higher) regardless of the economic feasibility.
CONCLUSIONS: The service life of long-life asphalt pavements was found to be approximately 50% longer than that of HMA pavements, regardless of the traffic volume characteristics. The economic feasibility of long-life asphalt pavements was evaluated based on the KoPMS. The results of the economic analysis were the following: long-life asphalt pavements are exceptional in terms of almost all factors, such as user cost, delay cost, total cost, and user benefit; however, the exception is the maintenance cost. Further, the economic feasibility of the long-life asphalt pavements in group B was found to be better than that of the HMA pavements (crack 25% or higher).
본 연구는 장수명 아스팔트 포장 공법개발 연구의 일환으로 포장수명을 40년이상 지속시킬 수 있는 단면설계를 수행하였다. 본 연구의 목적은 포장체의 장수명화를 위하여 효과적이고 간편하게 포장체의 각층 단면두께 및 탄성계수를 결정하는 절차를 제시함에 있다. 포장체의 유한요소 해석을 통하여 장수명 아스팔트포장의 가상데이터베이스를 구축하였다. 이 가상데이터베이스는 포장체 각 층의 두께, 탄성계수 및 포장체 내의 처짐, 응력 및 변형률을 포함하고있다. 구축된 데이터베이스를 이용하여 포장의 장수명에 필요한 한계변형률을 만족하는 포장의 단면을 제시하였다. 연구결과, 총 아스팔트층의 두께가 410mm보다 큰 경우에는 포장층의 각층의 두께나 재료의 특성과 관계없이 항상 장수명 아스팔트 포장으로 간주할 수 있으나, 250mm보다 작을 경우에는 장수명 아스팔트 포장에서 제외되었다. 총 아스팔트층의 두께가 250mm보다 크고 410mm보다 작은 경우에는 장수명 아스팔트 포장 조건에 만족하기 위한 포장층 두께와 탄성계수값을 결정할 수 있는 절차를 제시하였다.