Research on the connection performance and micro-hydration mechanism of super-performance grouting material for prefabricated component connections

The performance of grouting material determines the connection reliability of prefabricated components and the overall safety of the structure. In order to realize the rapid connection of prefabricated components, improve the construction efficiency and improve the quality of component connection. The research group has developed a grouting material with fast early strength improvement and high late strength. The formation mechanism was analyzed by scanning electron microscopy (abbreviation-SEM). The reliability of grouting material was verified by uniaxial tensile test of sleeve grouting connector. The results show that : Ca(OH) 2 (abbreviation-CH), ettringite (abbreviation-Aft) and calcium silicate hydrate (abbreviation-C-S-H) are formed inside the grouting material, and the cementing system is dense inside. The skeleton formed by AFt inhibits the shrinkage of the system, which can provide support for the later compressive and flexural strength. Uniaxial tensile test results and theoretical analysis. The external reinforcement of the sleeve is broken, and the bonding performance between the grouting material and the reinforcement inside the sleeve is reliable. The internal bond stress is far less than the failure stress of the connector, which is about 50% of the failure stress.