Physicochemical synergy and rheological performance of asphalt mastics modified with industrial waste precipitated calcium carbonate

This study investigates the performance of asphalt mastics incorporating precipitated calcium carbonate (PCC), an industrial waste by-product, as a sustainable alternative to conventional mineral fillers. The research evaluates the impact of PCC on rheological behavior, adhesion properties, and distress resistance across a broad temperature range. A factorial experimental design was employed, and the results were validated using Two-way Analysis of Variance (ANOVA). Filler-to-bitumen (F/B) weight ratios from 0.6 to 1.2 were analyzed using multiple stress creep and recovery (MSCR), linear amplitude sweep (LAS), and bending beam rheometer (BBR) tests. Surface free energy (SFE) results confirmed that the high basicity of PCC (\:Γ\:⁻= 556.11 mJ/m²) significantly enhances the work of adhesion and stripping resistance. Findings indicate that replacing base filler with PCC improves rutting resistance by 17.8% and fatigue life by 20.7%, with an F/B weight ratio of 1.2 identified as the practical upper limit. Statistical analysis revealed that while PCC dosage is the dominant factor, both filler type and concentration significantly influence the stress relaxation rate (m-value). Although higher PCC dosages lead to increased creep stiffness and reduced m-values—potentially impacting low-temperature cracking resistance—the non-significant interaction between filler type and dosage (P = 0.18) indicates a consistent and predictable rheological trend across different PCC sources. These results demonstrate that PCC significantly enhances high and intermediate temperature performance through strong physicochemical bonding, while its dosage must be optimized to balance stiffness and thermal relaxation. Utilizing PCC not only optimizes pavement performance but also promotes environmental sustainability by effectively upcycling industrial waste.