Stone mastic asphalt (SMA) pavements were developed to prevent rutting, abrasion, and various pavement deteriorations and to increase the life of the superstructure. They certainly stand out with their high grain contact, stone-stone interlocking ability, and high bitumen ratio on heavy-traffic roads with heavy axle loads. This study aimed to investigate the effects of basalt fiber in different sizes, partly cellulose, and partly basalt fiber addition, on the drain down of the performance of bitumen and the changes in rutting performance as additives to stone mastic asphalt pavements. To determine the absorption performance of bitumen fiber additives, 19 mixtures were pre-pared and the Schellenberger drain down test was carried out. The results, including the witness mixture, showed that the Schellenberger test result was below the value specified in the motorway technical specification by a maximum of 0.3%. For the Hamburg wheel tracking test (HWTT) additive and witness mixtures were prepared at optimum bitumen ratios using a gyratory compactor. HWTT was applied to the mixtures numbered 1, 4, 10 and 14, which have the best the Schellenberger drain down performance, and the witness sample. As a result of the experiments, the highest rutting deformation was measured at the samples using 12mm basalt fiber at the rate of 0.2%. The lowest rut deformation was measured in samples containing 12mm basalt fiber at the rate of 0,3% and cellulose fiber at the rate of 0.2%. It was determined that the combined use of cellulose and basalt fiber mixture improved the resistance against rutting by 37%. As a result of the HWTT, it was determined that stone mastic asphalt mixtures with basalt and cellulose fiber additives were more resistant to rutting than the witness and basalt-only mixtures.

Rutting is a key factor affecting the safety, durability, and performance of asphalt pavements. Its effective control requires proper design, material selection, and construction practices. Reclaimed Asphalt Pavement (RAP) offers environmental and economic advantages by reducing the need for virgin materials and minimizing construction waste. Incorporating RAP and basalt fibers can further enhance rutting resistance, thereby improving pavement longevity and structural performance. This study investigates the development of reclaimed asphalt pavement (RAP) mixture using. The RAP content was set at 15%, 30%, and 45%, with the addition of 6 mm long and 3‰ basalt fibers. The Hamburg wheel tracking test was used to evaluate the mixture's resistance to permanent deformation. The results indicated a decrease in rut depth and surface peeling as the RAP content increased. Notably, asphalt mixtures with 0% RAP and 3‰ basalt fibers demonstrated lower rut depths compared to control samples. The experiments showed that RAP mixtures exhibit superior rutting resistance compared to hot mix pavements. Additionally, integrating recycled materials and basalt fibers significantly enhanced rutting resistance, as evidenced by the incorporation of 45% RAP and 3‰ basalt fiber, which resulted in nearly a 47% decrease in rutting depth. Future research may focus on evaluating the crack resistance of asphalt pavements reinforced with high tensile strength basalt fibers.

Taxi fleets operate intensively, accumulate high annual mileage, and contribute disproportionately to urban greenhouse gas emissions, making them attractive candidates for transport electrification. Despite growing interest in electric mobility, integrated evaluations of the environmental, energy, and economic implications of taxi fleet electrification remain limited, particularly for medium-sized cities in Türkiye. This research examines the replacement of the commercial taxi fleet operating in the central districts of Denizli with battery electric vehicles (BEVs) through a framework that integrates operational emission estimation, electricity demand, charging infrastructure, and life-cycle cost analysis (LCCA). Operational emissions were quantified using the IPCC Tier 1 fuel-based approach together with a distance-based consistency check. Under the adopted assumptions, electrification reduced annual operational CO₂ emissions by 4217.48 tCO₂ (57.9%). The electrified fleet required 18.36 MWh of electricity per day (6.70 GWh annually), while estimated peak charging demand varied between 1.22 MW and 5.57 MW, depending on the charging strategy. Economic evaluation showed a positive net present value (NPV) of 1.32 million TL per vehicle, an internal rate of return (IRR) of 80.86%, and a discounted payback period (DPP) of 1.37 years. Although profitability varied with energy prices, vehicle costs, and annual mileage, fleet electrification remained economically feasible across all scenarios considered. These results suggest that electrifying commercial taxi fleets can support urban decarbonization while remaining financially attractive when accompanied by appropriate charging infrastructure and coordinated transport planning.

This study examines the technical and economic effects of incorporating Reclaimed Asphalt Pavement (RAP) and basalt fiber into asphalt mixtures within the framework of sustainability and circular economy principles. Twelve mixtures with varying RAP (0–45%) and fiber (0–3‰) contents were tested using the Tensile Strength Ratio (TSR) and Hamburg Wheel Tracking methods. Results showed that RAP significantly improved rutting resistance and reduced costs, achieving up to 34% savings at 45% RAP. Although basalt fiber slightly increased initial costs due to higher bitumen demand, it enhanced durability and reduced long-term maintenance needs. Overall, RAP supports circular economy goals by lowering material and energy use, while basalt fiber strengthens mechanical performance, offering a balanced and sustainable pavement solution.