Estimating and reducing the release of Greenhouse Gases in local road pavement constructions

Abstract

Local roads, which comprise 91% of the road networks in Indonesia, are a vital part of the transportation infrastructure. The construction of local roads has had some negative impacts on the environment, one of the most significant of which is the release of greenhouse gases (GHG). In order to develop a strategy for sustainable development in transportation infrastructure, it is essential that GHG emissions be reduced in the local road construction cycle. The aims of this study were to estimate the release of GHG and to elaborate on efforts to reduce GHG emissions in the construction of both rigid and flexible local road pavements. First, a life cycle assessment was performed to calculate the energy consumption and amount of GHG emissions. Next, some possible approaches were explored and elaborated on to seek opportunities to reduce GHG emissions, and therefore, enhance the sustainability of local road constructions. The results showed that material processing and material transportation contributed to 74.0-75.2% and 24.7-26.5% of GHG emissions, respectively. It is also known from the stepwise analysis that the significant predictor to form the amount of GHG both on the rigid and flexible pavement is the distance of the aggregate source to batching/asphalt mixing plant. Hence, the strategies for the reduction of GHG emissions, in this case, might be carried out by substituting current construction materials (cement and asphalt) with less intensive GHG emissions materials, and by reducing the distance for the transportation of the aggregates. The result shows that the first proposed strategy, which is substituting cement or asphalt with fly ash and reclaimed asphalt reduces more GHG than the second one.