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Go to Editorial ManagerThis comprehensive study undertakes a two-tiered comparative analysis to systematically evaluate the fatigue and cracking performance of a 40-50 penetration grade asphalt binder and its corresponding asphalt concrete mixtures, modified with varying dosages (2%, 4%, and 6% by binder weight) of Nano-Alumina (NA) and Nano-Silica (NS). The experimental methodology involved extensive binder-level testing, including the evaluation of physical properties (penetration, softening point, ductility), rheological behavior (Rotational Viscosity (RV)), and fatigue characteristics using the Superpave parameter G* sin δ and the advanced Linear Amplitude Sweep (LAS) test. Furthermore, compatibility was assessed via storage stability and Scanning Electron Microscopy (SEM). The research culminated in mixture-level performance evaluation using the Indirect Tensile Cracking Test (IDEAL-CT) to derive the Cracking Tolerance Index (CT-Index), Flexibility Index (FI), and Crack Resistance Index (CRI). The results confirmed that both nanomaterials significantly enhance binder stiffness and thermal stability. Nano-Alumina (NA) consistently induced the most profound stiffening effect, reflected by a major reduction in penetration. Rheological and LAS testing indicated that NA provides a stable and progressive, dose-proportional enhancement in fatigue life from 2% to 6%, attributed to the formation of a sustained nanoscale reinforcement network. Conversely, Nano-Silica (NS) exhibited a potent viscosity-building effect due to its high surface area, achieving superior initial cracking tolerance and fatigue life at low concentrations (2% to 4%). Crucially, the study identified a narrow optimal range for NS; concentrations at 6% led to an adverse reduction in fatigue resistance (G* sin δ increase) and diminished flexibility, suggesting a constraint imposed by excessive stiffening and potential particle agglomeration. Mixture-level IDEAL-CT results further validated these trends: NA offered a balanced overall contribution, maximizing the CT-Index at 6% and CRI at 4%, while NS yielded an exceptionally high CT- Index value at 2% but showed a decline in performance at higher contents. The overall findings recommend an optimal practical dosage of 2-4% for NS and 4-6% for NA, underscoring the necessity of material-specific optimization for achieving enhanced durability and fatigue life under repeated loading.
The growing demand for energy, coupled with the continued dominance of fossil fuels as the primary energy source, necessitates eco-friendly technologies that simultaneously enhance oil recovery (EOR) and reduce the impact of their emissions. Only one task, which is the CO2-EOR project, can combine these two sustainable development goals. Further, employing green nanotechnology, including nanoparticles and nanofluids, ensures a sustainable approach to controlling and enhancing rock wettability, thereby enhancing hydrocarbon production and carbon storage. However, the performance of nanofluids in subsurface formations is limited by the stability of these nano-dispersions at the harsh conditions of reservoirs. This work thus synthesizes silica nanoparticles from waste bentonite as a green source and modifies the surface properties with a silane group to formulate a stable nanofluid for subsurface applications. The produced nanoparticles were characterized via Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), zetasizer, and dynamic light scattering (DLS). Moreover, the efficiency of nanoparticles as wettability-modifying agents was studied using contact angle and spontaneous imbibition tests. FTIR measurements confirmed the presence of silane on the surface of hybrid silica nanoparticles, as indicated within the Wavenumber 2950 cm-1. Moreover, XRD measurements revealed that hybrid nanoparticles showed lower noise than pure ones. Results also showed that silane-treated nanoparticles (hybrid) are more tolerant to high salinity (≥ 0.5wt% brine), and green-synthesized nanoparticles have a drastic ability to invert the wettability of oil-wet surfaces (θ≥123°) to water-wet (θ ≤ 28°) at ambient conditions and also reduce the contact angle from 175° to 68°) at CO2-EOR conditions. The study concludes that these green nanofluids are highly efficient for EOR and carbon geosequestration projects when properly formulated.