Crack sealant shall be a modified asphalt-fiber compound designed specifically for improving the strength and performance of the parent asphalt sealant. a. The asphalt binder shall consist of a blend of neat asphalt binder, chemically modified crumb rubber (CMCR), and a polymer package, all of which meet the following specifications: The binder will meet PG 64-28E requirements after modification including: o PG grade requirements of AASHTO M320 o Requirements of AASHTO TP70/MP19 Modification, at a minimum, shall consist of 7% crumb rubber, and the maximum particle size for the recycled tire rubber shall be 80 mesh (#80 sieve) The asphalt supplier shall provide testing for both the neat and modified asphalt binders See below for typical modified test results for 64-28E with crumb rubber: DSR ORIGINAL • kPa >1.00 @ 64° C. Fail temp = 76+° C DSR RTFO • kPa >2.20 @ 64° C. Fail temp = 76+° C MSCR • JNR (MSCR unit of measure): 3.2 E <0.5% @ 64° C • R3200 (Average % Recovery): >70% DSR PAV • kPa <6000 @ 64° C BBR • Stiffness <300 @ -18° C. M-Value >0.300 @ -18° C b. Fiber reinforcing materials shall be short-length polyester fibers having the following properties: Length* 0.25 in. ± 0.02 in. Elongation at Break (ASTM D2256-90) 35% ± 3% Melting Point (ASTM D3418-82) >475 degrees F (246 degrees C) Crimps/Inch (ASTM D3937-90) None Cross Section Round Denier (ASTM D1577-90) 4.5 Nominal dpf Tensile Strength (ASTM D2256-90) >70,000 psi Diameter 0.0008 in. ** Specific Gravity (ASTM D792-91) 1.32 to 1.40 * At temperatures ranging from ambient to maximum finished product mix temperature ** Subject to Normal Variations
