Effect of asphalt pavement construction on the environment of Ethiopia

Nowadays road construction is rapidly increasing on-demand to meet several medium and long terms development programs. A huge amount of natural resources, types of machinery and fuels are used in road construction. Using material resources and fuel an efficient manner, reducing in emission of greenhouse gases and controlling various impacts on the environment are important tasks in the road construction industry. In the present research, several environmental impacts related to the construction of asphalt paved highways in Ethiopia have been determined using the Life Cycle Assessment Approach for common pavement materials and construction activities. A deep focus has been given towards the extraction and processing of sand and gravel for preparation of base and sub-base; transportation of these input raw materials; consumption of fuels by various road construction machinery; direct or indirect emissions of carbon dioxide and other pollutants to atmosphere etc. Various suitable methods have been used to calculate the impacts of raw materials, fuel and machinery on various categories such as global warming potential, ozone depletion potential, terrestrial acidification potential, freshwater eutrophication, freshwater ecotoxicity etc. From the investigation, it has been suggested to use recycled materials for substituting gravel as base or sub-base materials and biodiesel for substituting diesel in the transportation trucks and dumpers. These types of new recycled materials may greatly help in assisting the evaluation of sustainable pavement construction. The present case study may help for potential changes in asphalt pavement construction to improve environmental sustainability.