Strategic strengthening of the interfacial transition zone (ITZ) between microfiber and cement paste matrix with carbon nanofibers (CNFs)

• Main Authors: He, Shan, Yang, En-Hua
• Other Authors: School of Civil and Environmental Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Civil engineering; Interfacial Transition Zone; Fiber Reinforcement
• Online Access: https://hdl.handle.net/10356/160670
• Institution: Nanyang Technological University

The interfacial transition zone (ITZ) governs the mechanical properties and durability of fiber-reinforced cement-based composites. It has been reported that strategic strengthening of the ITZ by simple coating of carbon nanofibers (CNFs) on microfibers resulted in a 22% enhancement of the fiber/matrix bond. In the current study, ingenious methods were used to characterize such CNF-reinforced ITZ (CNF-ITZ). Results show that strategic application of CNFs greatly densified the ITZ with much reduced voids and defects. A distinctive hairy microstructure, resembling the setae on the toes of geckos, and less portlandite were found in the CNF-ITZ. The indentation hardness and indentation modulus were enhanced in both the radial and the tangential directions. The resulting CNF-reinforced ITZ is tougher and stronger with improved mechanical properties against deformation and cracking, which leads to enhanced fiber/matrix bond and elevated load transfer efficiency between fiber and matrix.