INVESTIGATION OF THE TRIGGER MECHANISM OF SELF-HEALING OF CONCRETE BY MICROGRANULES

Introduction. Concrete, as a traditional building material, was first developed by the British civil engineer John Smeaton in the 18th century. In 1894, the Frenchman Joseph Monier first injected concrete into molds with steel bars, giving birth to reinforced concrete structures. Since then, concrete has been used to protect steel bars and improve the load-bearing capacity and safety of structures. However, concrete has a fatal flaw in its resistance to tension, so the repair of concrete as a branch of concrete materials has received widespread attention from both academic and engineering communities in the past decade. Methods. The addition of encapsulated millimeter particle units during the concrete mixing phase has been proven to be an effective implementation of autonomous concrete repair. In the development of self-healing concrete, the encapsulation unit and trigger design are important factors that determine the work performance of self-healing units and the overall repair efficiency of concrete. Results. This article describes the passive and active trigger in two directions, further explaining the main triggering mechanism of concrete self-healing and the corresponding repair mechanism, as well as compares and analyzes the technical characteristics and application range of various self-healing triggering mechanisms, providing a reference for future product development.