Have you used Multiple Stress Creep Recovery (MSCR) to characterize bitumen rutting performance?
MSCR is one of the best bitumen tests to evaluate the performance of #polymer modified #bitumen:
#HiMA bitumen specification:
MSCR %R at 3.2kPa, 76⁰C: min 90%
MSCR Jnr at 3.2kPa, 76⁰C: max 0.1
Brookfield viscosity at 135⁰C: max 3 Pa.s
· MSCR provides creep compliance (Jnr) and % Recovery (%R) at two stress levels (0.1 and 3.2kPa)
· For conventional bitumens testing is usually performed at pavement high service temperature
· Generally the lower the creep compliance, the better the bitumen rutting performance
· High % Recovery allows the bitumen to resist permanent deformation through elastic rebound (only polymer modified bitumens can do it)
· MSCR is very sensitive to the quality of polymer network, which makes it a great tool to specify Highly Modified Asphalt (#HiMA)
Associated standards:
· ASTM D7405 - 20
· AASHTO T350
· EN 16659