Two of the most common polymers used in asphalt binder of the elastomer variety are SBR (styrene - butadiene - rubber, also known as latex) and SBS (styrene - butadiene - styrene).

• A. Not given
• B. True
• C. False
• D. Cannot determine

Answer: (B)

Elastomer-modified asphalt relies on rubbery polymers to make the binder more elastic and resistant to deformation. Two of the most common polymers used are SBR and SBS. SBR stands for styrene-butadiene rubber, a synthetic rubber that blends well with asphalt and provides good elasticity at a lower cost. SBS is a styrene-butadiene-styrene triblock copolymer, whose hard styrene end blocks and soft butadiene mid-block create a robust, elastic network inside the asphalt. This network helps the binder resist rutting at high temperatures and cracking at low temperatures, while also improving aging resistance. Because of their compatibility with asphalt, effectiveness, and wide availability, SBR and SBS are indeed among the most widely used elastomeric polymers in asphalt binders.