A Comparative Life Cycle Assessment (LCA) of Warm Mix Asphalt (WMA) and Hot Mix Asphalt (HMA) Pavement: A Case Study in China

Hui Ma,Shuang Wu,Zhigang Zhang,Xia Zhao

doi:10.1155/2019/9391857

Hui Ma, Shuang Wu + Show 2 more

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https://doi.org/10.1155/2019/9391857

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Abstract

Generally, the warm mix asphalt (WMA) technology can reduce the mixing and paving temperature effectively as compared with that of hot mix asphalt (HMA), which is considered more environment-friendly. In this study, the environmental impacts and resource consumptions of WMA and HMA pavements were analyzed comparatively using the life cycle assessment (LCA) method. A LCA model of pavement was built; meanwhile, the relevant life cycle inventory (LCI) of WMA and HMA pavements was also collected and analyzed. The midpoint impact categories including Global Warming Potential (GWP), Chinese Abiotic Depletion Potential (CADP), and Particulate Matter Formation (PMF) were assessed for five cases. The assessment results showed that the resource consumptions of both WMA and HMA pavements in entire life were almost at the same level, while the environmental impacts of WMA pavement related to greenhouse gases and PM2.5 emissions were significantly less than that of HMA pavement, except for the case where the long-term performance of WMA pavement is much worse than that of HMA pavement. In final, it could be concluded that WMA pavement is more environment-friendly compared with HMA pavement although they have the same-level resource consumptions.

Highlights

Nowadays, transport is vital for the well-functioning of economic activities and a key to ensuring social well-being and cohesion of populations
According to ISO standards [25, 26], generally, life cycle assessment (LCA) incorporates four phases: goal and scope definition, life cycle inventory (LCI), life cycle impact assessment (LCIA), and life cycle interpretation. e goal and scope definitions of LCA determine the guidelines to be followed during the rest of the assessment. e goal decides the model type and evaluation index of LCA. is study aimed to evaluate the environmental impacts and resource consumptions of warm mix asphalt (WMA) and hot mix asphalt (HMA) pavements during their entire life cycle, which is expected to facilitate more informed decision as environment-sensitive pavement construction comes with the uncertainty of newly constructed WMA pavement
Besides the case 5, which assumed WMA performance is much worse than HMA, WMA pavement exhibits pronounced reduction of total Global Warming Potential (GWP) when compared with HMA pavement. is is mainly caused by less fuel burning and CO2 emission due to the lower mixing temperature of WMA, as indicated by a 46.7% GWP reduction of WMA over HMA when asphalt-mixture production is considered separately

Summary

Introduction

Transport is vital for the well-functioning of economic activities and a key to ensuring social well-being and cohesion of populations. Transport ensures everyday mobility of people and is crucial to the production and distribution of goods. The construction and maintenance of transportation infrastructures has become and will continue to be a significant contributor to the consumption of raw materials and greenhouse gases emissions worldwide. In America, more than 350 million tons of raw materials were consumed each year in highway construction and maintenance [1]. A third of total CO2 emissions were contributed by the transportation industry in Denmark, of which 95% comes from the construction and operations of transportation infrastructures [2]. In China, the highway industry contributed about 290 million tons of CO2 emissions in 2004, and the predicted emission is expected to reach 1.1 billion tons in 2030 [3]

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