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The goal of the current study is to create environmentally friendly bituminous paving mixes that make extensive use of waste products like recycled concrete aggregate (RCA), reclaimed asphalt pavement (RAP) and waste polyethylene. A control mix with conventional stone aggregates (CSA) and VG40 bitumen was taken into consideration for the comparison study. It was noticed that the modified RAP mixes significantly enhanced the performance of the control mix in terms of Marshall stability and rutting resistance. Waste polyethylene was shown to be less prone to moisture-induced damage when added to modify the RAP mixes made with pre-treated recycled concrete aggregate (PRCA) or CSA. The performances of modified RAP mixes incorporating waste polyethylene and CSA or PRCA showed significant improvements. The modified RAP mixes made using various combinations of PRCA-CSA and waste polyethylene can be considered as good substitute for the CSA-VG40 control mix, and can therefore improve the high and intermediate temperature performance.

The present study was carried out to assess the effectiveness of surface treated Montmorillonite Nano Clay (NC) on performance of bitumen. The modification of bitumen was prepared using VG-30 grade bitumen with different percentages of NC by weight of bitumen (3% to 6%). Prior to mixing, surface of NC modified with Octadecyl amine and Aminopropyltriethoxysilane. Temperature susceptibility was evaluated using activation energy parameter. Rutting behavior was characterized using temperature sweep and multiple stress creep recovery tests. Fatigue performance was assessed using temperature sweep and linear amplitude sweep tests. Results inferred the potential benefit of NC in lowering the degree of temperature susceptibility. The trend of performance parameters indicate significant improvement in rutting and fatigue cracking resistance. Moreover, optimum dosage of surface treated NC was found to be 4.5% at which the binder showed significant improvement in resistance to rutting, fatigue and high temperature aging without affecting the storage stability property.

The present study was carried out to evaluate effects of regular sized hydrated lime (RHL) and Nano-sized hydrated lime (NHL) on rutting resistance performance of asphalt mastic related to stiffness, creep, relaxation and recovery properties. The study utilises AC-30 binder with different combinations of basalt-RHL and basalt-NHL fillers for the preparation of asphalt mastic specimens. The dosages of RHL and NHL fillers were chosen as 0%, 5%, 10%, 15% and 20% by weight of asphalt binder, and percentage of basalt filler were adjusted accordingly to meet a filler to binder (F/B) ratio of 0.8 (by mass ratio). The rutting performance of asphalt mastic at high temperatures was evaluated using different tests such as Superpave rutting factor, static shear creep, and high stress Multi Stress Creep Recovery (MSCR). Overall test results indicate that specific surface area and interaction properties of RHL and NHL fillers with asphalt have a significant effect on the rutting performance of asphalt mastic. The results from Superpave rutting factor, static shear creep, and high stress MSCR test showed that both RHL and NHL filler have the potential to enhance the rutting resistance properties (stiffness, recovery and creep) of asphalt mastic, also, combination of basalt and NHL filler had superior performance than combination of basalt and RHL filler. In addition, asphalt mastic with NHL filler found to be less sensitive to high stress levels and thus, possessed better viscous and elastic response compared to RHL filler. Furthermore, asphalt mastic with a lower percentage of NHL filler had better rutting resistance performance (related to stiffness, creep, relaxation and recovery) over mastic with a higher percentage of RHL fillers.

The present investigation was carried out to understand the effectiveness of Chitin (Ch) on thermal susceptibility, rheological and ageing resistivity behaviour of Sulphur (S) modified bitumen binder (SMB). The modified bitumen binders were prepared in the laboratory using a VG-30 binder with 2% sulphur and different dosages of ‘Ch’. The dosages of Ch were varied as 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, and 3% by weight of VG-30. All combinations of ‘Ch’ modified SMB binders were subjected to three stages of ageing namely unaged, short-term ageing and long-term ageing as per test requirements. Rutting performance was evaluated using Superpave rutting factor (G*/sinδ) and MSCR parameters such as non- recoverable creep compliance (Jnr), and percentage recovery (R). Fatigue damage behaviour was characterised using Superpave fatigue factor (G*sinδ) and linear amplitude sweep (LAS) tests. Ageing resistivity was calculated based on softening point, G*/sinδ, and Jnrvalues, and assessed in terms of the ratio of the respective parameter of aged sample upon unaged sample. The resulting trend indicates that the surface characteristics, elemental, and interaction potential of ‘Ch’ and ‘S’ may have a strong influence on the performance of the bitumen binder. Viscosity test results imply that addition of ‘Ch’ showed a lower degree of thermal susceptibility, which may require less compaction effort for applications of the bituminous mix in the field. G*/sinδ, Jnr, and Rvalues signify a clear indication of an increase in rutting resistance ability with the incorporation of ‘Ch’ in SMB binder. It is observed that the inclusion of ‘Ch’ in SMB binder has the potential to enhance the fatigue life at intermediate temperature. Similarly, resulting ageing index values showed that SMB binder is less susceptible to ageing with addition of Ch. This study showed that the combination of SMB with Ch can be beneficial to enhance the rutting and fatigue resistance of bitumen binder with low thermal and ageing susceptibility behaviour.