Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE This study proposes a premixing strategy for devulcanized rubber powder (DRP) and asphalt to induce pre-swelling and interfacial reconstruction before asphalt modification. Premixing promotes rubber dispersion and compatibility within the asphalt matrix, resulting in enhanced penetration, ductility, and storage stability while effectively mitigating phase separation in rubberized asphalt systems.

ABSTRACT
The recycling of waste tire rubber powder in asphalt modification has attracted increasing attention, while poor compatibility limits its engineering applications. To improve the compatibility between devulcanized rubber powder (DRP) and asphalt, a premixing strategy was proposed by blending DRP with base asphalt at mass ratios of 9:1, 8:2, and 7:3 before asphalt modification. Premixed DRP-modified asphalts (PDRA) were subsequently prepared, and basic performance, storage stability, aging resistance, and microstructural characteristics were systematically investigated. The results indicate that premixing effectively mitigates phase separation and improves the dispersion uniformity of DRP within the asphalt matrix. PDRA exhibits excellent storage stability, with the minimum softening point difference reduced to 1.1°C. SEM and FM analyses reveal that premixing promotes the swelling and partial dissolution of DRP, resulting in smoother particle morphology and fewer undissolved agglomerates. FTIR and TGA results further demonstrate that premixing enhances the exposure of polar functional groups, broadens the thermal decomposition range, and promotes a smoother pyrolysis process. Overall, premixing improves the interfacial integration between DRP and asphalt and provides an effective pretreatment strategy for the sustainable application of waste tire rubber powder in asphalt pavements.