Technology of self-healing road pavements: current status and development prospects

Abstract

Introduction. Presently, there exists no unified methodology that could control self-healing properties of materials due to the lack of criteria characterizing the ability of materials to respond to impacts and to cope with adverse effects produced on their properties or structure. All assessment methods applied to self-healing properties of materials are reduced to the calculation of the ratio of relative changes in the value of parameters to be measured. A “self-healing” material is a material capable of initiating liquidation of structural defects, so that the rate of this process could exceed the one of spontaneous propagation of defects, while the resistance of the new structure to operating loads is not lower than the initial one. Development of solutions, capable of implementing this principle, will ensure longer service lives of materials.
 Materials and methods. A set of general methods of logical research was applied. These methods are based on the theoretical analysis of process solutions presented in professional editions, information resources maintained by their developers and in mass media, patents, research articles and reports.
 Results. The self-healing technology is applicable to asphalt concrete with regard for its structural features and thermoplastic properties. Self-healing means restoration of the structural integrity of physical and chemical bonds by moistening crack surfaces, diffusion of molecules between them, and arbitrary dissipation of molecules to ensure reinforcement. Self-healing process uniformity is attainable by applying the technology of functional agent encapsulation so that it could be added to the mix along with other components at the stage of the asphalt concrete mix preparation.
 Conclusions. Existing technological solutions can generate capsules that contain the recovery agent in the amount of up to 90…94 % of the total volume. General requirements and quality standards that apply to self-healing materials, used in construction, must be developed to identify their efficiency depending on application conditions. Provisions of the adhesion theory can be applied to the self-healing technology in the course of its implementation.
 The study was funded by the grant from the Russian Science Foundation (Project No. 19-79-00262).