An investigation on the multi-scale characterizations of basalt-fiber-reinforced warm mix asphalt composites

Incorporating fiber stabilizers into warm mix asphalt (WMA) to enhance the performance has been a significant subject, which facilitates the realization of green road paving and extends the durability of asphalt pavements. This study emphasizes the potential of basalt fibers as a promising additive for WMA materials. The rheological properties of WMA binders were examined by dynamic shear rheometer, multiple stress creep recovery, and bending beam rheometer tests, along with the influence of basalt fibers on the microstructure and composition of WMA binders through atomic force microscopy and Fourier transform infrared spectroscopy. Subsequently, the construction workability and pavement performance of basalt-fiber-reinforced WMA mixtures were analyzed by conventional asphalt mixture tests. The results indicated that sufficient heating and mixing resulted in a modest increase in the viscosity of the WMA binder containing 6% Aspha-min. There were not significant chemical reactions between the four WMA binders and basalt fibers, but the mixing caused noticeable changes in surface structure and morphology of asphalt binders. Notably, Energy Champion 120 had the most significant influence on the component structure of asphalt binders, nearly eliminating the "bee-like" structure. The introduction of basalt fibers led to a slight increase in both mixing and compaction temperatures. Additionally, all four additives had an adverse effect on the water damage resistance performance of asphalt mixtures, and none of them was able to enhance the properties associated with both high and low temperatures. Through comprehensive evaluation and analysis, basalt fiber has a significant enhancement effect on the comprehensive performance of the WMA mixtures.