Durability of high-volume fly ash concrete subjected to drying-wetting cycles and carbonation coupling effects

Abstract

This paper presents an experimental study on the durability properties of high-volume fly ash concrete that is suitable for channel revetment. The durability of the high-volume fly ash was determined after the material was subjected to carbonation and drying-wetting cycles. In comparison to the single damage process, the coupling effects caused the weight of the concrete to increase while decreasing the relative dynamic modulus of elasticity. In addition, carbonation depths in the concrete were significantly greater than they were in the standard carbonation test. Environmental scanning electron microscope was used to investigate the microstructure variations in the high-volume fly ash concrete. This analysis revealed that coupling effects caused damage to the concrete. The incorporation of fly ash obviously influences the concrete weight loss and relative dynamic modulus of elasticity. The carbonation resistance of the fly ash concrete is lower than that of the reference concrete.

Keywords:

• High-volume fly ash concrete
• Drying-wetting cycles
• Carbonation
• Coupling effects
• Durability