Polymer Modified Bitumen
Polymer Modified Bitumen have binders whose properties have been modified by the use of a modifying agent which when added to the original bitumen alters its chemical structure and/or physical and mechanical properties in order to make it more resistant to temperature variations, weather and high traffic loads.
Commonly used modifying agents are polymers. depending upon the nature of the polymer, these modifiers can be classified as :
Plastomers: EVA (Ethylene Vinyl Acetate) , EBA (Ethylene Butyl Acrylate), ETP(Ethylene Ter Polymer) etc.
Elastomers: SBS (Styrene-Butadiene Styrene), SIS (Styrene isoprene Styrene).
Advantages of using PMB
- Increase in softening point and decrease in the brittleness ensures more protection against hot Climatic Conditions
- increase in elastic recovery ensuring protection against cold climatic condition
- Better adhesion of the binder to the aggregate
- Water resistance properties are increased
- Resistance to stripping and low temperature cracking
- Resistance to fatigue and rutting
Application of PMB
- On Heavy traffic levels, curves, crossroads etc.
- Where there is risk of high and low road surface temperatures
- For heavy duty applications
- As Bond coats
- To improve durability in remote areas
- In high rainfall areass and high stress conditions.