Investigation of the effect of waste wask fiber usage on asphalt mixture performance

With the increasing problems such as global warming, environmental pollution, and depletion of natural resources, sustainability efforts have become more important than ever. In the transportation sector, the development of environmentally friendly and sustainable applications in asphalt pavement materials is among the primary goals. In this context, the upcycling of waste materials stands out as an important strategy for both protecting the environment and increasing the durability of road pavements. In this thesis study, the usability of single-use waste face masks as a fiber additive in hot mix asphalt was investigated. Using a full factorial experimental design, masks cut into different lengths (10 mm, 15 mm, and 20 mm) and added in varying proportions (%0,05, %0,1, %0,15, and %0.2) were evaluated in the experimental studies. A total of 36 Marshall specimens were prepared, and the results were compared with reference specimens. An ANOVA (Analysis of Variance) table was generated using SPSS software, and the statistical significance of the independent variables (fiber ratio, fiber length) on the dependent variable (asphalt mixture performance) was examined. The indirect tensile test was applied to the mixture with the highest Marshall stability value. As a result of the study, it was observed that the addition of masks at specific proportions and lengths enhanced the durability of the mixture. Analysis of variance revealed that, at a 95% confidence level, the fiber length variable had a statistically significant effect on Marshall stability, whereas the fiber content and the interaction between fiber content and fiber length did not have a significant effect. According to the Marshall stability test results, the addition of %0.1 mask fibers with a length of 15 mm resulted in a greater increase in strength compared to other samples. It exhibited approximately 10% higher strength compared to the reference sample. This mixture also showed an increase in fracture energy density at 20°C based on the results of the indirect tensile strength test.