Determining The Contribution Of Different Structural Layers Of Asphalt Pavement System To Rutting Using Transverse Profile Analysis

Abstract

Rutting is one of the major distresses which cause hydroplaning and structural failures in a flexible pavement. The extent of damage depends upon the load induced and the strength of each pavement layer. Rutting can occur due to the failure of the subgrade, the base or at the wearing surface/ hot mix asphalt (HMA) layer(s). In order to take remedial measures, it is imperative to be cognizant of the contribution of each layer to ascertain the cause of underlying phenomena of rutting. This research study demonstrates the procedure of analyzing the pavement transverse surface profile that could be used to identify the layer responsible for the permanent deformation. Transverse surface profiling technique is easier, non-destructive, and economical as compared to traditional methods of coring and trenching to examine underlying layers. A 300 m section on National Highway (N-5) was selected exhibiting severe rutting to perform transverse profile analysis. Results of this study suggest that rutting at the selected site is mainly due to the shear failure of HMA layer. These results were also validated by field trenching on the test section. It is inferred that as the rut depth increases, the negative area goes on increasing for a particular failure mode. The study further concluded that HMA layer should be removed and replaced with appropriately designed high performance mix specifications.