Polymer Modified Bitumen-Boon for Indian Roads

Posted by Metal Barrier on April 5th, 2018

A large amount of money is invested in the construction of roads in India every year. Yet it has been observed in many remote locations the durability of these roads have been short termed. Highly populated cities and density of traffic in many areas is the reason for such drawbacks.

As the connectivity has increased between various cities in India through well-established road networks so has round the clock movement of heavy loaded vehicles.The road networks therefore had to be designed with the quality of materials which ensured sustainability over a longer run.

Nowadays, Bitumen is obtained as a byproduct from the process of distillation of Petroleum, and is widely used as a binder for the aggregates in pavements. This ensures strength of roads. Polymer Modified Bitumen (PMB)as the name suggests modifies the binding quality of the bitumen. This is done through a chemical reaction which increases its resistance to stress and cracks.

Major Advantages:

• Improved Elasticity
• Suitable for enhancing durability by resisting cracks and deformations
• Increased stability in response to temperature variations
• Increased water resistance makes it indispensable in heavy rainfall locations

Main polymers used with Bitumen as modifiers:

SBS - styrene-butadiene-styrene-copolymer: The component Styrene has the properties of hard Plastic which grants the durability to the mixture. Butadiene carries the properties of a rubber which adds the elasticity to the mix.

EVA- Ethylene vinyl acetate: The components of EVA makes it porous like a rubber retaining its toughness. It also has low temperature variability .Presence of EVA increases the softening point making it less brittle and decreasing penetration of modified bitumen decreases.Thus,hardening the bitumen and improving its quality.

Standard PMBs available in the market:

• PMB70 Ideal for Moderate Climatic conditions
• PMB40 Ideal for Hot areas
• PMB 120 Ideal for Cold climate areas

Polymer Modified Bitumen is supplied by distributors to roads construction companies. Traditionally vessel for combining bitumen with polymers were continuously heated to mix them properly. The heat generated was harmful and was a lengthy process. Nowadays there are many Polymer Modified Bitumensuppliers in India that are using modern technology and mixes components in one go.

Bitumen when ages it loses its binding properties. Therefore the polymer selected for bitumen needs to be chosen as per its predominant qualities. The mix of polymer and bitumen is tested in extended temperatures to make sure its original qualities does not deviate much when the temperature is increased.