Polymer-modified bitumens

Article 212 of the General Technical Specifications for Road and Bridge Construction Projects (PG-3) defines polymer-modified bitumens, in accordance with norm UNE-EN 12597 on Terminology, as: "hydrocarbonated binders whose rheological properties have been modified during their manufacture, through the use of one or more organic polymers. For the purposes of applying this article, organic or mineral fibers are not considered bitumen modifiers."

The modifying agents and technology used to manufacture these binders have made it possible to improve the mechanical and rheological properties of traditional bitumens, providing improvements in adherence to aggregates, less susceptibility to temperature, and greater resistance to aging, thereby making it possible to extend pavement durability.

The technology developed by Repsol has given rise to the comprehensive range of polymer-modified bitumens included in Article 212 of the PG-3, from bitumens intended for high-module mixtures such as PMB 10/40-70 to bitumens used for anti-crack mixtures such as PMB 45/80-75.

All these bitumens have excellent storage stability, achieved through chemical reticulation processes during manufacturing, making it possible to obtain a product with the best characteristics and compliant with the required specifications.

The type of modified bitumen to be used depends on the type of mixture, its position on the paving, the weather, and the type of traffic. That said, the main applications of each can be listed:

- PMB 10/40-70

• High-module bitumen mixtures for roads with T00 and T0 traffic.

- PMB 25/55-65

• Mixtures resistant to plastic deformations
• Mixtures resistant to fatigue in new works or in reinforcement layers

- PMB 45/80-60

• Draining mixtures on wearing course for T1, T2, and T3 traffic
• Discontinuous mixtures on wearing course for T1, T2, and T3 traffic.

- PMB 45/80-65

• Draining mixtures on wearing course for T00 and T0 traffic
• Discontinuous mixtures on wearing course for T00 and T0 traffic.

- PMB 45/80-75

• Anti-crack mixtures
• High-performance mixtures for wearing courses

- PMB 75/130-60

• High-performance mixtures for wearing courses
• Sand-bitumen