Study on rheological properties and damage mechanism of asphalt under acid-alkali precipitation corrosion

Abstract

This research delved into the effects of pH precipitation on asphalt's rheological characteristics and damage mechanisms. We analyzed the shifts in asphalt's acid-alkali corrosion properties through macro and micro tests. To begin with, we conducted three cycles of bitumen corrosion tests using acidic, alkaline, and neutral solutions. Subsequently, the dynamic shear rheological test (DSR) measured the complex shear modulus, phase angle, and rutting factor before and after asphalt corrosion, revealing correlations between corrosion duration, temperature, and asphalt's rheological traits. Additionally, we evaluated post-corrosion changes in asphalt's functional groups through infrared spectrum testing, allowing us to deduce the underlying damage mechanism. Our results showed that asphalt's deformation resistance was directly related to soaking time and inversely related to temperature. The complex shear modulus exhibited an inverse relationship with temperature, while the phase angle demonstrated a direct proportionality to temperature variations. From a chemical perspective, acidic components within asphalt tend to dissolve and ionize, while alkaline substances undergo esterification and neutralization. Notably, asphalt modified with styrene–butadiene–styrene (SBS) exhibits enhanced resistance against acid and alkali corrosion, surpassing the performance of the 90# asphalt. Ultimately, this research established a theoretical framework for exploring acid-base precipitation resistance in asphalt binders, contributing to our understanding of asphalt's binder properties and broadening its applications.