8 Pages

The influence of intergrinding of cement and fly ash on concrete durability

B. Czarnecki & W. Johnston W. Dobslaw

ABSTRACT: The benefits of using fly ash in concrete include improved durability to thermal cracking, decreased permeability, improved resistance to sulphate attack and mitigation against alkali-silica reactivity. Blended cements combine Portland cement with one or more supplemental cementitious materials (SCM). Blended cements can be sourced as on-site or blended by cement producers to meet a variety of specifications. This paper presents the results from a comprehensive experimental programme to determine the effect of binary blends with Class F fly ash on the properties of concrete. The study shows that intergrounding of cement with fly ash results in a reduced expansion of concrete due to sulphate exposure when compared to Type HS cement concrete mixes. Chloride penetrability and strength development is improved. The impact of intergrounding of cement and fly ash on the microstructure of concrete and effective levels of fly ash replacements for durability is assessed.