Recent developments in the application of chemical approaches to rubberized asphalt

Although rubberized asphalt has more than a 50-year history, it has not been widely adopted due to difficulties with its processability, unstable properties and high initial cost. Chemical approaches, including chemical characterization and the addition of chemical additives to rubberized asphalt, are useful tools to promote the applications of this technology. Chemical characterization techniques such as infrared spectroscopy, thermogravimetric analysis, gel permeation chromatography, and sol-gel analysis are used to analyze the chemical composition of rubberized asphalt. The development of chemical characterization for rubberized asphalt is described in terms of chemical degradation of rubber in asphalt, and stabilization of rubber in asphalt. The evolution of the chemical composition of rubberized asphalt has been evaluated and correlated for dry and wet processing, and indoor and outdoor aging. Following this, high performance rubberized asphalt realized by modification with different chemical additives is also discussed. The additives are categorized into polymers, inorganic filler, plasticizer and others. Finally, methods that combine several types of different additives that can be used to produce rubberized asphalt with stable properties and in an environmentally friendly manner are described.