Life Cycle Assessment of Road Surface Paving with Warm Mix Asphalt (WMA) Replacing Hot Mix Asphalt (HMA)

Based on a testing road construction project, where warm mix asphalt (WMA) replaced Hot Mix Asphalt (HMA) to be used on road surface paving, investigation was carried out to collect data on energy consumption and air emissions for all the steps including production of raw materials (HMA and WMA), transportation, paving and road surface rolling. Then life cycle assessment was performed to compare the environment impacts of road surface paving with WMA and with HMA based on the data collected above. The life cycle assessment inventory was obtained and assessment results showed that when using WMA and HMA as road surface paver, energy consumption in the full process was reduced by around 22.4%; and environment load was released by saving impact potentials of many impact categories: due to the reduced air emissions from WMA producing and paving, more than 70% of photochemical ozone formation (POF) potentials was saved when compared to HMA paving; above 55% of impact potentials was saved for three impact categories: Global warming100 years (GW100), Acidification (AC) and Human Toxicity via air (HTa), respectively. In conclusion, by using WMA substituting HMA as road surface paving course material, positive effects on energy conservation and environmental load release can be achieved.