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Highlights • New resilient modulus master surface approach was developed. • The approach characterizes both granular pavement materials and subgrade soils. • The approach considers the effect of stress state and moisture content levels. • The proposed master surface-2018 model produces accurate predictions. Abstract Resilient modulus is a fundamental material property used for pavement materials characterization. A new methodology for predicting the resilient modulus of unbound/stabilized pavement materials and subgrade soils is developed based on a master surface function at a reference water content. The resilient modulus measurements at different levels of water content are shifted horizontally with respect to the octahedral shear stress, and bulk normal stress; simultaneously. A total of 2754 resilient modulus laboratory measurements, obtained from literature, for five granular base materials, four subgrade soils, one recycled crushed concrete material, and three cement-treated stabilized fine materials are used to evaluate the proposed Master Surface model for the resilient modulus prediction as a function of the stress state, and water content. The proposed predictive methodology is compared to well-known models from literature. The comparison of the investigated models exhibits that the Master Surface model has the most precise and unbiased predictions after numerically optimizing the resilient modulus data. [ABSTRACT FROM AUTHOR]

Currently, sustainable pavement research focuses on modified asphalt binders with self-healing features for achieving durability and safety goals. This study assesses the self-healing behavior of asphalt binders incorporating innovative lab-manufactured hybrid-structured phase change material capsules (HPCMC). The HPCMC, using by-product paraffin oil as a core encapsulated by waste nano-silica fume as a shell, varied in core-to-shell ratios (0.5:1, 1:1, 2:1) and dosages (1 %, 3 %, 5 %, 7 %) by asphalt weight. Morphological, thermal, and chemical characterizations were conducted using scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). Healing efficiency of unaged and short-term aged HPCMC-modified binders was evaluated using SEM and energy dispersive X-ray (EDX) for morphological and chemical analysis. Rheomechanics were examined through rotational viscosity (RV), performance grading (PG), multiple stress creep recovery (MSCR), strain sweep (SS), frequency sweep (FS), linear amplitude sweep (LAS), and linear amplitude sweep-based healing (LASH). Study findings exhibit superior healing in HPCMC-modified binders compared to unmodified ones, particularly at a 3 % dosage and 1:1 core-to-shell ratio in unaged conditions. This study also evaluates healing assessment criteria and validates the self-healing mechanism, indicating significant potential for the proposed approach to revolutionize pavement construction and maintenance. [Display omitted] • Innovative and sustainable self-healing approach through the incorporation of HPCMC to enhance asphalt binder durability. • Synthesis and characterization of HPCMC through morphological analysis, thermal stability, and chemical investigations. • Evaluation of rheomechanical performance and healing efficiency of HPCMC-modified asphalt binders under varied aging states. • Optimization of core-to-shell ratios and HPCMC dosages to maximize healing efficiency and rheomechanical performance. • Validation of self-healing mechanism, proving HPCMC's ability to repair microcracks and boost pavement quality. [ABSTRACT FROM AUTHOR]

• Recycled Plastic Waste (RPW) improved virgin (VA) & sulfur extended asphalt (SEA). • RPW made VA&SEA stiffer/elastic thus better resistance to rutting/fatigue cracking. • Addition of RPW to VA&SEA slowed the oxidation reactions of the binder. • Addition of RPW to VA&SEA made binder more suitable for wider range of temperature. • The modification effect of RPW on asphalt included chemical and physical processes. This study examines the effect of two different recycled plastic waste (RPW) which are high and low-density polyethylene (RHDPE and RLDPE) on the rheological/viscoelastic characteristics and aging performance of virgin asphalt and sulfur extended asphalt (SEA). Four dosages of the RPW additives representing 2%, 4%, 6%, and 8% by weight of the asphalt binder were investigated. The rheological characteristics of the RPW modified binders (virgin and SEA) are characterized at original and short-term aging conditions through the Rotational Viscometer (RV) and dynamic shear rheometer (DSR) tests. Fatigue performance is also characterized at the long-term aging condition. Also, high-temperature performance, dynamic storage stability (DSS), multiple stress creep and recovery (MSCR) are studied. Testing results show that RPWs lead to improved rutting and fatigue performance. Adding RPW to the virgin and SEA binders slows the binder oxidation reactions during the short-term aging. The Aging Index (AI) is found to be dependent on the asphalt rheological properties, amount/type of RPW, binder type, and temperature. RHDPE leads to an unstable modified virgin asphalt. Less than 4% RHDPE or 8% RLDPE with virgin asphalt show good DSS in terms of degradation and separation. The RPW with SEA meets the requirement of time degradation and separation set by the Federal Highway Administration (FHWA). The temperature susceptibility of asphalt binder decreases dramatically with the RPW modification making the asphalt binder more suitable for use at a wider range of temperatures. [ABSTRACT FROM AUTHOR]