Energy consumption and environmental impact of rubberized asphalt pavement

The focus of this paper is to evaluate the energy consumption and environmental impact of rubberized asphalt pavement during the life cycle. Reducing the environmental influences of the highway infrastructure has received the increasing attentions recently. Application of crumb rubber in asphalt pavements overcomes the used tires disposal problem and achieves materials savings and environmental benefits, due to the reduction of raw material and extension of pavement service life. In addition, rubberized asphalt production is a highly energy consuming process due to a higher mixing temperature. However, the warm mixing technology can lower the mixing temperature of rubberized asphalt mixture, leading to approximately 20-25% of fuel savings. Moreover, the consumed energy of rubberized asphalt during maintenance phase is lower than that of conventional asphalt. In addition, the greenhouse gas (GHG) emissions from the production and construction of rubberized asphalt mixtures are similar to those from hot mix asphalt, but their emissions of CO and CH4 are much lower. Meanwhile, the noise reduction is an environmentally friendly benefit. The leachate from asphalts used wet and dry-process crumb rubber modifiers (CRM) does not pose a measurable threat to the environment. Rubberized asphalt technology as a green technology in term of lowering GHG emissions, saving energy and raw material and reducing noise level of pavement should be widely used to achieve environmental sustainability.