Influence of Surface Texture on Interface Bond Shear Strength of Asphalt Concrete

Influence of Surface Texture on Interface Bond Shear Strength of Asphalt Concrete

Civil Engineering Beyond Limits (CEBEL)
Volume 1 - Issue 3 - July 2020

Saad Issa Sarsam Samah Abdulrazzaq AL Nuaimi

Abstract

The bonding strength provided by the tack coat between asphalt concrete layers at the interface is considered as an essential issue in the performance of the flexible pavement throughout its service life. However, the surface texture of the pavement surface exhibit another essential issue in the bond strength. In this investigation, three layers of asphalt concrete (base, binder and wearing) courses with (25, 19, and 12.5) mm of nominal maximum size of aggregates have been prepared using roller compactor. Rapid curing cutback RC70 and cationic medium setting emulsion CMS have been implemented as tack coat with three application rates. The slab specimens were subjected to mean texture depth determination using sand patch method. Core specimens of 102 mm diameter were obtained from the prepared slab samples and subjected to interface bond strength test with the aid of special manufactured mold. Test results were analyzed and compared. It was concluded that when RC-70 tack coat was implemented, asphalt concrete binder course laid on base course exhibit the highest shear strength of 1600 kPa at an application rate of 0.33 liter/m2 when compared to other application rates. Asphalt concrete wearing course laid on binder course exhibit the highest shear strength of 1515 kPa at an application rate of 0.15 liter/m2 when compared to other application rates. When CMS tack coat was implemented, asphalt concrete binder course laid on base course exhibit the highest shear strength of 1620 kPa at an application rate of 0.23 liter/m2 when compared to other application rates. However, the asphalt concrete wearing course laid on binder course exhibit the highest shear strength of 2272 kPa at an application rate of 0.23 liter/m2 when compared to other application rates.

Keywords

Cutback, Emulsion, Tack coat, Asphalt concrete, Interface bond, Texture
https://doi.org/10.36937/cebel.2020.003.002