Asphalt is considered one of the most essential materials used for road construction because of the high energy requirement for its production and its large greenhouse gas emission. VG30-grade asphalt is extensively utilized in road constructions as a binding material due to its ideal viscosity and superior performance characteristics at different climatic conditions, particularly in nations such as India. Biochar are materials, produced from organic biomass by pyrolysis. This study examined the influence of biochar produced from plant biomass as an alternative binder modifier for pavement. The investigation focused on the feasibility of using biochar at different percentages of 2.5%, 5%, 7.5%, and 10% by weight of VG30 to make it sustainable. Various physical experiments carried out included penetration test, softening point test, storage stability analysis and ductility test. Additional rheological tests carried out included rotational viscosity, original binder grading and Multiple Stress Creep and Recovery (MSCR). The findings demonstrated that using a binder modified with biochar led to significant improvement in rheological parameters, including enhanced rutting resistance, higher failure temperature and improved percentage recovery (R%). A decrease in the Non-Recoverable Creep Compliance (Jnr) value was also observed. The results showed therefore, that asphalt treated with biochar became more capable of resisting high temperatures. Thus, it can be determined that the biochar-modified binder at a 10% concentration is the most effective one regarding performance. The research emphasizes that biochar is a promisingly effective material that can enhance asphalt performance and contribute to improve agricultural waste management.

This study presents a simple, yet robust testing methodology employed for investigating the mechanical behaviour of soils under cyclic loading conditions. Small cylindrical specimens of soil (10.5 mm diameter and 35.0 mm high) were subjected to oscillatory torsional loading in either strain sweep or stress sweep mode using the dynamic shear rheometer. Key mechanical properties, including dynamic shear modulus, phase angle, and energy dissipation capacity, were obtained and used to effectively identify threshold strain levels which differentiated the linear, nonlinear, and damage response of the soil. This study further applied the proposed method to stabilized soils to evaluate the effects of stabilizers on improving soil stiffness, while also considering their potential effects on increasing soil brittleness, which could ultimately lead to reduced resistance to fatigue cracking. The successful development of this testing protocol has the potential to evolve into a specification-type method due to its efficiency, repeatability, sensitivity, and fundamental robustness.