Published: November 2011 | Category: Activity management , Research programme , Research & reports | Audience: General
Research was undertaken in 2009–11 to evaluate the potential benefits of multigrade bitumens in chipsealing in New Zealand.
A field trial demonstrated that multigrade bitumen seals could be constructed without significant modifications to existing practice except that higher spraying temperatures are required and adhesion agent choice is limited.
Experimental measurements of bitumen-tyre adhesion temperatures were made using a rolling wheel apparatus. The cohesive energy of bitumen in artificial seals at 60°C under impact loading was studied using a pendulum device. In both tests, the results for multigrade bitumens were found to be similar to standard bitumens of similar 25°C penetration even though the 60°C viscosity of the multigrade materials was 2-3 times higher.
Keywords: adhesion, chipseals, cohesion, multigrade bitumen, penetration, polymer-modified bitumen, viscosity.
