Crumb Rubber Modified Asphalt: Fundamentals to Recent Developments

Accumulation of polymeric solid wastes is a matter of distress and concern in the modern era. Plastic wastes are easier to recycle than rubbers, especially composite products like tires are very difficult to recycle. Finding sustainable end-of-life solutions for waste rubber products is crucial at present. The use of ground rubber, popularly known as crumb rubber obtained from the shredding of waste rubber goods in the construction of road pavements is one of the best possible ways to recycle rubber. About a billion end-of-life (ELT) tires are globally discarded every year, yet the use of crumb rubber generated from these tires in road construction is still negligible. The addition of crumb rubber not only permits the consumption of a significant amount of waste rubber but also provides numerous benefits to asphalt road pavement. Crumb rubber improves the rutting resistance, fatigue cracking and durability of roads. Rubberized asphalt roads also exhibit reduced traffic noise and increased driving safety. Though there are some limitations of crumb rubber as an additive, such as phase separation and poor workability, recent technical advancements are finding ways to overcome them. Further development of this technology is crucial for the establishment of a sustainable and circular economy.