The creation and use of asphalt contributes to an increased amount of pollution. The production of asphalt releases volatile organic compounds, such as the carcinogens benzene and toluene, which have adverse health implications. The oil in the asphalt does not allow asphalt to absorb water and therefore dries out the soil underneath it, which leads to its degradation. Additionally, it traps in heat within the surrounding environment, contributing to the “heat island effect”, which is not conducive for combating climate change. Asphalt is generally produced and laid at very high temperatures, increasing the amount of CO2 emitted. By finding alternative methods and materials for surfacing, the negative implications of the transport sector can be reduced.
Italy has begun using concrete instead of asphalt pavement in tunnels due to the positive impacts on CO2 emissions. Concrete is light in color, which improves visibility for road users and calls for less lighting, which reduces energy consumption, as well as the costs and emissions for installing and maintaining lighting installations. Concrete does not deform when exposed to high temperatures and has a service life of at least 30 years, which requires less maintenance and repair work and ultimately a reduction in CO2 emissions. By reducing the amount of maintenance and repairs, raw materials are saved and ultimately, up to 30% in potential energy savings which lead to decreased CO2 emissions compared to asphalt.
Asphalt industry can make a significant contribution towards reducing CO2 emissions by using high quality asphalt that can be mixed and laid at lower temperatures. Approximately 50% of production energy is consumed by heating the asphalt, lowering the temperature achieves significant savings in fuel consumption. Low-temperature asphalt not only reduces emissions in heating and drying, but in laying as well. There are three methods that can reduce the temperature—bitumen foam (70), waxes (50) and zeolites (40). Less energy required to heat the aggregates, less CO2 emitted during production, lower emissions from the hot mix during truck loading at the asphalt mixing plant, and lower emissions on the road construction site during laying.