Lifetime Performance of Polymer-Modified Bitumen in Swedish Roads Evaluated With Survival Analysis

Abstract

This study uses survival analysis to estimate the lifetime of Swedish asphalt paved roads. The roads were separated by binder type, such as unmodified bitumen and polymer-modified bitumen (PMB). Road pavements with PMB were compared to equivalent roads with regard to annual average daily traffic, heavy vehicles, road type, road width, speed limit, construction year, region, bearing capacity, pavement type, stone size, and rut bottom distance. The analysis was based on almost 500,000 records of pavement maintenance and road condition measurements from the Swedish Transport Administration’s Pavement Management System database, dating back as far as the 1970s. The results showed that PMB in the surface layer was expected to extend road lifetimes by 15% compared with bitumen. PMB in the underlying layer gave an 8% increase in life expectancy compared with unmodified bitumen. PMB in both layers gave a 24% increase in expected road lifetime compared with unmodified bitumen in both layers.