Summary of Rubber Modified Asphalt Product Specifications around ...
Summary of Rubber Modified Asphalt Product Specifications around ...
Summary of Rubber Modified Asphalt Product Specifications around ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
3.0 <strong>Asphalt</strong> <strong>Rubber</strong> Binder <strong>Specifications</strong><br />
By definition <strong>of</strong> ASTM D8, asphaltrubber is a blend <strong>of</strong> asphalt cement, reclaimed tire rubber,<br />
and certain additives in which the rubber component is at least 15% by weight <strong>of</strong> the total blend<br />
and has reacted in the hot asphalt cement sufficiently to cause swelling <strong>of</strong> the rubber particles<br />
[ASTM D8-97]. The ASTM D6114 further defines the detailed requirement on base asphalt<br />
cement, ground recycled tire rubber, and three types <strong>of</strong> asphalt rubber binders. Type I is<br />
recommended for use in hot climates; Type II is recommended for use in warm climates; and<br />
Type III is recommended for cold regions [ASTM D6114-97(2002)]. The following section<br />
summarizes the specifications on the asphalt rubber binder from the agencies surveyed.<br />
3.1 Crumb <strong>Rubber</strong><br />
Crumb <strong>Rubber</strong> Modifier (CRM) is an important component <strong>of</strong> the asphalt rubber and rubber<br />
modified asphalt. The typical specifications for CRM from various agencies are summarized in<br />
Table 1. The CRM generally used in terminal blend is much finer than the one used in field<br />
blend. For field blended asphalt rubber, Ontario’s CRM gradation is finer than in California and<br />
Arizona. However, California also uses a high nature rubber and extender oil which Ontario<br />
does not use. The asphalt modifier specified by California is a resinous, high flash point,<br />
aromatic hydrocarbon compound. Ontario’s CRM is also finer than Type A <strong>of</strong> Arizona, Grade A<br />
<strong>of</strong> Texas, New Jersey, and China. It is similar to Type B <strong>of</strong> Arizona and Grade B <strong>of</strong> Texas. but it<br />
is coarser than Grade C <strong>of</strong> Texas and Types A, B, and C <strong>of</strong> Florida. Finer CRM makes it easier<br />
to blend and interact with base asphalt binder. Ontario’s CRM is on the medium to fine side.<br />
However, it doesn’t have a maximum moisture content requirement. Additives such as calcium<br />
carbonate are not used in Ontario’s specifications.<br />
Table 1. Comparison <strong>of</strong> CR <strong>Specifications</strong> from Various Agencies<br />
Agencies Source Gradation Additives Other Notes<br />
MTO / Ontario<br />
Canada<br />
(Field Blend)<br />
Passenger<br />
vehicle tires<br />
only; not<br />
devulcanized;<br />
ambient or<br />
cryogenic<br />
ground rubber,<br />
or both; shall be<br />
dry and freeflowing<br />
#8:2.36 mm (100)<br />
#10:2.00 mm (100)<br />
#16:1.18 mm (80-100)<br />
#30:600 um (40-60)<br />
#50:300 um (5-15)<br />
#100:150 um (0-10)<br />
No CRM specific<br />
gravity 1.1 to 1.2<br />
2
Change language