Effects of Nanoparticles on the Antipullout Strength between the Reinforcement and Cement Mortar

Recently, the use of nanomaterials (i.e., Nano-Silica (NS) and Nano-SiC(NC)) to improve the mechanical properties and durability performances of cement-based materials has received considerable attention. This work presents the effects of nanoparticles (NS), the specimen size, and the water-reducing agent on the antipullout strength between the reinforcement and cement mortar on the basis of the laboratory antipullout tests. The mechanism is, then, validated by the microscopic analysis with Scanning Electron Microscopy (SEM). Results show that NS can accelerate the hydration reaction of cement, produce more Calcium Silicate Hydrate (CSH) gel, and increase the density of the cement mortar, thereby improving the microstructure and antipullout strength. The moderate NS (1.0%) is recommended to improve antipullout between the reinforcement and cement mortar. Besides, the specimen size and water-reducing agent have an obvious influence on the antipullout strength. These results would provide guidance on the design or construction of the cement mortar with reinforcement.