Polymer-modified Bitumens: Characteristics, Advantages and Challenges

Asphalt manufacturing, as a commercial material, especially in road construction, is increased on yearly basis. Unfortunately, in application conditions such as heat, temperature changes, precipitation (as snow, rain, hail and etc.) and pressure impact (resulting by vehicles, especially those heavy vehicles), cause much destruction of the asphalt. This leads to high maintenance cost. So, many efforts have been made to increase asphalt durability. One of the most promising methods is to add polymers into asphalt structure. Polymer-modified bitumens (PMBs) are known as a basic choice, especially in case of paving the streets and roads, in order to enhance asphalt durability. But these are grappled with serious limits, which most important are: high manufacture cost, difficulty of maintaining ideal work condition, instability and phase separation. To eliminate these problems, there is hardly a remedy except subtle cognition of components of bitumen, their properties, polymer role in modifying, components solubility in polymer, chemistry and structure of bitumen. Therefore, in this paper, following an account on PMBs and brief history of their manufactures, chemistry of bitumen is presented and the favorable polymer architecture in PMBs is demonstrated. Finally, general routes to modify or improve PMBs are introduced.