Extensive training activities were taken by the Fellow to enhance his expertise in theoretical material science and chemistry knowledge, multiphysics computational modelling and performance predictions, experimental material characterisation, and model implementation in industrial applications. In addition, project management, communication and networking skills were also developed via the project. Knowledge inter-transfer was also stimulated between the Fellow and the hosts. The main research activities and results achieved so far include:
• Multiphysics adhesion mechanisms of rubberised asphalt binders. The models for interrelated multiphysics adhesion mechanism contain 1) environmental physics; 2) chemical models for rubber swelling and dissolution, adhesion initiation; 3) mechanics-based constitutive modelling; and 4) microstructural morphology.
• Prediction model of adhesion multiphysics for rubberised asphalt binders. Circular dependencies between the Multiphysics of adhesion were identified and coupled with each other through material fundamental properties (e.g. surface energy, bond energy, diffusivity, modulus) and shared parameters and variables in the constitutive models. A systematic adhesion model was formed by assembling all separate models to interpret the fundamental adhesion mechanisms at the CRMB-aggregate interface.
• Experimental development and evaluation of the adhesion performance. Selective bitumen, aggregates and adhesion promoters were tested in the laboratory and examined using the proposed adhesion models and computational framework (Molecular dynamics simulations). Mechanical testing including dynamic shear rheometer (DSR) at varying testing conditions, surface free energy (SFE) measurements and bitumen bond strength (BBS) tests were performed to quantitatively evaluate the adhesive bond between CRMB and aggregate. Based on experimental and numerical results, an optimized evaluation protocol considering both materials design and service conditions was proposed to evaluate the effectiveness of the existing or newly developed adhesion promoters and technologies.
• Industry applications and feedback. The adhesive performance of industry bituminous binders at Total and industry asphalts at AI were evaluated using the proposed adhesion models and the developed computational performance prediction framework. New anti-stripping materials and technologies were potentially identified for industry use. Construction technologies and design practices were optimized based on the feedback from the industrial applications to increase the adhesion capacity and strength of CRMB.
The results of the project were disseminated and published to the most extent via multiple communication platforms such as printed publications (3 journal articles), 4 conference presentations, 2 workshops, 2 seminars and so on, which targeted a variety of potential users and partners including material companies, infrastructural designers, engineers, managers, contractors, and researchers throughout Europe and the world.
