Structural field evaluation of pilot crumb rubber pavement test sections in Saskatchewan

Abstract

In 2005, Saskatchewan Ministry of Highways and Infrastructure (SMHI) piloted the use of crumb rubber modified hot mix asphalt concrete (HMAC) in test sections on a primary highway. Crumb rubber surfacing did not significantly influence the heavy weight deflectometer measured structural performance of the pavement test sections. Ground penetrating radar analysis showed minimal difference in the surface permittivity of the crumb rubber HMAC and conventional SMHI Type 71 HMAC surfacing. A visual inspection of the test sections found that crumb rubber HMAC had a more open texture that appeared to mask the visual identification of transverse cracks. However, thermal and reflective cracks were observed to be present in both surface types. In summary, crumb rubber modified HMAC pavement in Saskatchewan did not yield significant difference in structural or surface condition compared to conventional SMHI Type 71 HMAC surfacing after 3 years of service in the field.