Rutting Performance Evaluation of the Bituminous Mixes using Roller Compactor and Rut Analyzer

The characteristics of the bitumen play a very important role in the performance and durability of flexible pavement. Conventional bitumen has many disadvantages, due to which the pavement undergoes different types of distress, such as cracking, edge breaks, shovelling, rutting, ravelling, heaving, potholes, etc. The performance of the bituminous mixes can be improved by using various types of additives to bitumen, commonly known as modifiers, to obtain modified bitumen. The present investigation is done by conducting Marshall Stability and Rutting tests on a combination of bituminous mixes, namely Bituminous Concrete (BC) Grade-I and Grade- II (Gr-I & Gr-II) used as a surface course layer and Dense Bituminous Macadam (DBM) Grade-II (Gr-II) used as a binder course layer, using both conventional bitumen and Crumb Rubber Modified Bitumen (CRMB). The pavement crust is built as per the specifications of the Indian Road Congress (IRC) 37, 2018. Rutting tests were conducted by indigenously developed equipment, namely the Roller Compactor and Rut Analyzer (RCRA). The results show that the Bituminous Concrete Gr-II mix has 20.1% and 32.4% higher strength than Bituminous Concrete Grade-I mix prepared with conventional bitumen and modified bituminous mixes, respectively. Also, modified bituminous mixes showed higher density and lower flow values than conventional bituminous mixes. The reduced flow values obtained with the modified bituminous mixes make the pavement surface less susceptible to temperature changes. Similarly, the results of rutting tests show the BC Gr-II mix exhibited 38.0% and 50.6% higher resistance to rutting than the BC Gr-I prepared with conventional and modified bituminous mixes, respectively. The findings of the research help in reducing the use of natural resources, reducing the cost of construction, enhancing pavement strength and performance, and simultaneously addressing and reducing the problem of waste disposal.