Silane coupling agent impact on surface features of modification of basalt fibers and the rheological properties of basalt fiber reinforced asphalt

Abstract

Rheological properties of fiber reinforced asphalt (FRA) can be significantly influenced by the surface properties of fibers. Modified basalt fibers are emerging materials used to enhance the performance of FRA. Silane coupling agents (SCAs) make it possible to introduce versatile surface features to basalt fibers (BFs). Six typical SCAs were tested and evaluated for modifications on the rheological properties of BF reinforced asphalt at different high-level temperatures. The specific characteristics of each modified BF was measured by dynamic surface tension meter, denoted as surface energy components (SFEC), calculated using two distinct methods, OWRK (dispersive-polar approach) and vOCG (acid-base approach). The semi-quantitative correlation between SFEC based on each method and rheological properties with regard to temperature response were detailed. Study results show that Van de Waals interaction and acid-base interaction is more suitable to describe the interaction between asphalt and basalt fibers, and the interaction mechanism changes when temperature increases. Our research provides a guidance in the modification of SCAs when used in combination with mineral fillers to improve the overall performance of asphalt mixtures. Additionally, a novel SCA carrying long chain alkanes (UP312) shows high potential for modifying mineral fillers with excellent water resistance and improvement in the rutting resistance of asphalt concrete.