RET SBS Modified Asphalt

- January 01, 2016 -

Extensive test data is available from government agencies, asphalt materials experts and universities, showing Elvaloy® RET to be at least equal, but in most cases superior in performance to SBS-modified asphalt meeting a similar specification grade.

Slower pavement deformation and reduced damage from moisture and temperature extremes, are among the reasons why a well-designed asphalt paving mix made with RET-modified binder can deliver a longer-lasting return on the owners' investment in infrastructure.

Compare the Polymers

Differences between RET and SBS begin with basic polymer chemistry and handling properties.

REACTIVE ELASTOMERIC TERPOLYMER (RET)	STYRENE BUTADIENE STYRENE (SBS)
• Specifically engineered by DuPont and Chevron for asphalt modification	• Polymer developed in 1940s, primarily for adhesive markets.
• Storage-stable, since Elvaloy® RET chemically links with the asphalt	• SBS is a dispersion of polymer in asphalt; therefore, separation is possible.
• Rail car or barge shipments are possible with Elvaloy® RET.	• Bulk PMA shipment is more difficult due to risk of separation.
• PMA can be winter-filled and stored for reheating and use later.	• Winter-filling is not recommended.
• Gentle mixing is all that is needed; a high-shear mill can be used, but isn't necessary.	• High-shear mill required for mixing; increases capital and maintenance investment.
• Elvaloy® RET is delivered as a free-flowing pellet, so it can be bulk stored and shipped.	• SBS is not bulk shipped or stored.

Compare the Processing

Terminal operators and paving contractors can also benefit from proven Elvaloy® RET asphalt modifier technology.

REACTIVE ELASTOMERIC TERPOLYMER (RET)	STYRENE BUTADIENE STYRENE (SBS)
• Lower storage, mixing and compaction temperatures	• Higher storage, mixing and compaction temperatures
• Less energy use in mix plant	• More energy use in the mix plant
• Less likely to have smoking issues	• More likely to have environmental emissions (smoking) from the mix plant if extra additives are applied
• Compaction can be obtained more quickly, getting traffic back on the mat sooner.	• Longer compaction times, long lane closures; harder to construct during ever increasing night/weekend paving windows
• Much less likely to cause fume complaints	• Complaints to authorities about fumes, from workers and the public
• Fewer complaints from job site neighbors.	• More likely to have fumes at the paving train due to higher temperatures
• Mat less likely to shove/move due to lower temperatures.	• More likely to have shoving, moving, and tender mix issues
• Paving crew will think Elvaloy® RET modified asphalt paves much like a neat asphalt.	• Harder to pave with. Crews inexperienced with PMA can have serious paving issues.
• As mix cools, Elvaloy® RET solidifies to \"lock in\" paving performance.