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. |