Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE The graphical abstract illustrates the preparation, characterization, and pavement validation of asphalt containing activated rubber powder (ARP). Waste rubber tires are first converted into ARP through controlled desulfurization, followed by the preparation of anti-cracking composite modified asphalt (ACA) via high-shear blending. The microstructural evolution, chemical interactions, and rheological properties of ACA are systematically evaluated using microscopy and spectroscopic techniques. Finally, the pavement performance of ACA mixtures is verified through tests, demonstrating the feasibility and performance advantages of ARP-based sustainable asphalt materials.

ABSTRACT
Waste tire rubber powder has become a widely used and sustainable replacement for asphalt modification. The traditional waste tire rubber-modified asphalt exhibits poor low-temperature performance, leading to frequent cracking in regions with lower temperatures. To effectively reutilize waste rubber tires and enhance the crack resistance of asphalt pavement, this study utilized styrene-butadiene-styrene (SBS) and waste tire rubber powder treated with activated desulfurization to prepare anti-cracking composite modified asphalt (ACA). ACA was synthesized using the response surface method (RSM). Subsequently, the basic properties and anti-aging performance were tested and compared, showing that ACA demonstrates superior high- and low-temperature performance and aging resistance. Rheological tests confirmed ACA's outstanding high-temperature rutting resistance and low-temperature crack resistance. Notably, ACA exhibited a self-healing capacity 3.9 times greater than SBS-modified asphalt, showcasing superior fatigue resistance. Moreover, characterization of ACA's microstructure and morphology revealed that the rubber powder showed good compatibility with asphalt, SBS, and flexibilizer, forming a stable cross-linked network within ACA. This structural feature is a key factor contributing to ACA's superior overall performance and crack resistance. Finally, pavement performance tests validated ACA's performance in asphalt mixtures, demonstrating a novel approach utilizing SBS and rubber powder to enhance asphalt's anti-crack performance while recycling waste rubber tires.