Research Projects

Pavement durability is crucial in tropical countries like India, where roads are exposed to seasonal environmental variations. The longevity of pavements is primarily dependent on the compaction characteristics of subgrade, subbase, base layers, and bituminous layers, which can be affected by improper compaction. The bituminous layers of flexible pavements are the top-most layers and are exposed to both mechanical and environmental loads. Understanding the compaction behavior of these viscous granular mixtures is critical to minimize failures due to rutting, fatigue cracks, and moisture-induced damage. Conventional laboratory compaction devices do not fully capture stress states induced by different compactors and have a fixed stress path, making it difficult to study the effect of stress path on compaction. A comprehensive understanding of compaction characteristics under complex stress paths during static and dynamic loading conditions is needed to improve existing compaction methods and 3-D paving technology. The proposed study uses a temperature-controlled triaxial apparatus to quantify shear and volumetric changes induced in different stress paths. The effect of air void content, binder type, aggregate gradation, and bitumen viscosity on compaction behavior will be evaluated. A constitutive model based on thermodynamic framework will be developed to describe the response observed in the experiments. The model will be implemented using the finite element method to investigate different field compaction problems.