Performance Optimization and Framework Enhancement of Balanced Asphalt Mixtures Modified with Liquid Anti-Stripping Additives

• Assessed cracking, rutting, moisture damage, and durability using BMD approach. • A procedural improvement to BMD framework was proposed to better integrate moisture damage evaluation. • LAS improved cracking resistance and moisture durability without compromising rutting This study investigates the multi-domain performance of asphalt mixtures modified with a liquid anti-stripping additive (BHMT-HP) and proposes a procedural improvement to Balanced Mix Design (BMD) framework to better integrate moisture damage evaluation. The experimental program involved preparing asphalt mixtures at four binder contents (4.0%, 4.5%, 5.5%, and 6.0%) and modifying them with BHMT-HP at dosages ranging from 0% to 1.0% by binder weight. Key performance indicators were evaluated, including cracking resistance indices (i.e., CT Index , NFlex, FI, CRI, BCI, Weibull CRI ), rutting resistance indices (i.e., HT-IDT, dynamic creep), durability index (Cantabro loss), and moisture susceptibility index (Tensile Strength Ratio). Results demonstrated that BHMT-HP significantly improves moisture resistance and toughness up to a 0.50% dosage; however, higher dosages led to diminished cracking and deformation resistance. A multi-criteria analysis confirmed that 0.50% represents the optimal dosage, balancing moisture durability with structural performance. Based on these findings, the study proposes advancing moisture susceptibility testing to the trial phase of the BMD process, ensuring its consideration before final binder content selection. This procedural improvement reduces the risk of post-OBC corrections and aligns the BMD workflow more closely with field practice. Overall, the study highlights both the technical benefits of LAS and a practical enhancement to support more robust, performance-based asphalt mixture design.