Tire-derivedmaterial is utilized for its beneficial properties in asphalt toproduce rubberizedbinders.
These rubberizedbinders aremanufactured througheither fieldblendingor terminal blending
processeswhich are thenused in various applications such as hotmix asphalt (HMA), chip seals,
stress absorbingmembrane interlayers (SAMI) and slurry seals that provide cost-effective and superior
performanceover applications that utilize conventional asphalt.
Pavements
FieldBlendAsphalt Rubber Binder
In this process, the recycled tire rubber is added to asphalt in fieldblendingoperations. Theproduct
is calledAsphalt Rubber or the“wet process” andhas been successfully used inCalifornia andother
states. It is definedbyASTMD8, Volume 4.03 as: “Ablendof asphalt binder, reclaimed tire rubber,
and certain additives inwhich the rubber component is at least 15percent byweight of the total
blend andhas reacted in thehot asphalt binder sufficiently to cause swellingof the rubber particles”.
Terminal BlendBinder
In this process, the recycled tire rubber is added to asphalt at the refineryor at a stationary asphalt
terminal. Theproduct is calledTerminal Blend andhas beenused successfully inCalifornia andother
states. Terminal Blendbinders utilize a finemeshof crumb rubber derived from100% tire rubber and
blendedwith asphalt at high temperatures. TheTerminal Blendbinder is nowusing theperformance
grading (PG) specification system similar topolymermodifiedbinders, and theproduct canbe
emulsified.
Binders Benefitsmay include:
• Fatigue and reflective cracking resistance inhotmixes
• Better chip retention in chip seals
• Increased film thickness
• Higher elasticproperties
