Bitumen Modification

How it works

Every asphalt pavement is made of two components: aggregates and bitumen. The role of aggregates is to provide structural support. Bitumen is a glue holding aggregates together. Because asphalt pavements flex under traffic, bitumen needs to be strong and resilient. Kraton polymers have a unique molecular structure, which when mixed with bitumen, enhances their durability by adding flexibility, elasticity, and toughness over a wide temperature range. These features reduce the bitumen’s sensitivity to extreme temperatures and significantly enhance its performance properties.


Explore Our Bitumen Modification Solutions or  Bitumen Modification Enabled Technologies by Paving Application

Conventional & Premium PmB

Highly Modified Asphalt (HiMA)



Lower pavement lifecycle cost

Consider the following figure showing cost reduction per mile of pavement of a 40 year time period. Performance enhancements may lead to a dramatically reduced agency lifecycle cost depending on bitumen modification level.


Paving HIMA Economics https://kraton.com/products/paving/HiMAPavementEconomics-v3.pdf

Polymer network effect


Styrene-butadiene-styrene block copolymers have been the leading choice among technologies available for bitumen modification. SBS polymers combine excellent performance with unparalleled PmB production flexibility. Polymer modified bitumen performance derives from the strength and continuity of the polymer network inside.


Polymer content and type are the key determinants of the polymer network quality. As the polymer content increases its network becomes continuous. The bitumen turns from a viscous into a fully elastic solid.



Know Your Bitumen


Bitumen chemical composition becomes more and more variable. At Kraton we developed a proprietary bitumen database featuring a detailed analysis of over 350 globally sourced bitumens. By applying machine learning techniques, we can now better understand and predict the formulation performance, helping you achieve your project goals.


The following graph shows the predicting power of Kraton’s machine learning algorithm in predicting PmB’s elastic response solely based on unmodified bitumen characteristics.





Asphalt Binder  Modification - 101 Series

Learn about SBS and PmB formulation best practices: