Asphalt mixtures degradation induced by water, frost, and road salt in the 4-PB bending test evaluated by stiffness variability.

Water, frost, and road salt are important environmental factors that affect the durability of the entire pavement structure e.g. during the winter season or in regions located above sea zones. A proprietary experimental method was used to investigate the influence of these factors on mineral asphalt mixtures. Four road mix types of asphalt concrete (AC22) were analysed in the experiment. They differed in production technology, type, and content of the binder used. Based on the experimental approach and test data, changes in the value of the initial stiffness modulus (4-PB-PR test) were analysed. Based on the obtained results, it was established that both interactions caused a significant decrease in the module's value, which reached over a dozen percent. The article also evidenced that lower binder content in mixtures increases the negative environmental impact on the material, whereas its type may accelerate or reduce material degradation. [ABSTRACT FROM AUTHOR]