Thermal-rate sensitivity of the yield-to-fracture transition in asphalt matrices

This study establishes a comprehensive engineering framework to characterize the transition from ductile yielding to brittle fracture in the asphalt matrix, a critical factor in the durability of pavement materials. Through a systematic program of uniaxial monotonic tension and compression tests across a wide range of temperatures ( − 6 ° C to 36 ° C ) and loading rates, a pronounced compression–tension (C–T) asymmetry was quantified. Experimental results demonstrate that peak stress is governed by two distinct physical regimes: viscoplastic yielding at high temperatures and fracture-driven failure at low temperatures. A multi-mechanism model was proposed that integrates the Eyring cooperative model for the ductile regime with Griffith’s theory (tensile) and a modified Mohr–Coulomb criterion (compressive) for the brittle regime. By incorporating the rate-temperature superposition principle and the Richeton modulus model, the proposed framework accurately predicts the peak stress and captures the critical thresholds for failure mode transition. This unified approach provides a robust theoretical foundation for developing advanced non-linear constitutive models for asphalt-based composites.