Investigation of Effect of Aging on Reflection Cracking in Overlay

The use of a bituminous overlay for the extension of the service life of the pavement is the most common practice in India. Reflection cracking is a major type of distress observed in overlays constructed with the bituminous mix. Generally, the reflection cracking in a bituminous overlay is generated due to repeated traffic load, thermally induced stresses or strains, and a combination of both. The aging of the bituminous mix is also one of the causes of the formation of reflective cracks in the overlay. However, very limited studies are available on the effect of aging on the reflective cracking resistance of bituminous mix. Therefore, in this study, the effect of short-term aging and long-term aging on reflective cracking resistance of bituminous mixes prepared with viscosity grade bitumen and polymer-modified bitumen were evaluated in Texas Overlay Tester (TOT). The results of the test indicate that the resistance of bituminous mixes to reflective cracking was reduced with an increase in the severity of aging. The bituminous mix prepared with polymer-modified bitumen showed better resistance to reflective cracking caused by aging.