Quantifying sustainability for two types of pavement based on life cycle cost and environmental impact

Abstract

Abstract Several types of highway pavement have been adopted by various highway agencies, and each type has both advantages and disadvantages. Estimations of the life cycle cost and environmental impacts of pavement types have thus become major components of roadway planning, as the economic and environmental sustainability of pavements depends on both the project characteristics and the maintenance programme applied during the pavement life span. This article focuses on making a comparison of environmental impact in terms of Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA) of two arterial streets in Al-Diwaniyah city centre. The first street utilises flexible pavement, while the second street is constructed with composite pavement layers, with a Hot Mix Asphalt (HMA) wearing layer implemented over a Portland Concrete Cement (PCC) pavement. The comparison between the streets was conducted using Athena Pavement LCA software, and the resulting analysis clarified the impact of pavement type, construction process and maintenance conditions on the environment in each case, taking into in consideration all related parameters such as material, construction processes, and the maintenance and rehabilitation programmes applied to the pavements during their life cycle. The results showed that the environmental impact in terms of gas emissions for the street implemented with flexible pavement was 48% higher than that of street implemented with a composite structure; further, the initial cost for the flexible structure was 17% higher that of pavement constructed with composite PCC and HMA. The LCCA for the street with flexible pavement was also 78% higher than that of composite structure due to the additional maintenance activities required during its service life.