The Influence on High-Temperature Mechanical Properties of Hybrid-Fiber-Reinforced High-Performance Concrete and Microscopic Analysis
This paper investigated the high temperature mechanical properties of the hybrid fiber reinforced high performance concrete (HFHPC) and normal concrete (NC) .After being subjected to different elevated heating temperatures, two kinds of concretes have been tested for the compressive strength, splitting tensile strength and flexural strength of test specimen at room temperature and 200 °C,400 °C,600 °C,800 °C.Microstructure changes of concrete were also observed by using Scanning Electron Microscopy (SEM) after high temperature. The results show that the hybrid fiber can significantly increase mechanical properties of the concrete at room temperature and high temperature. SEM and XRD analysis shows that there is a permeable diffusion layer in the steel fiber surface because of solid state reaction in the Interfacial Transition Zone of steel fiber and concrete. This permeable diffusion layer is white, bright, serrated and mainly consist of FeSi2 and the complex hydrated calcium silicate. The compounds of this layer change the Interfacial Transition Zone structure, enhance bonding capacity of the steel fiber and matrix, and increase the high temperature mechanical properties of concrete.
Chunliang Zhang and Paul P. Lin
L. Yan et al., "The Influence on High-Temperature Mechanical Properties of Hybrid-Fiber-Reinforced High-Performance Concrete and Microscopic Analysis", Applied Mechanics and Materials, Vols. 226-228, pp. 1709-1713, 2012