State of the art for fly ash uses in concrete

An overview of accomplishments in recent research and of attractive further work for improvements of the uses of fly ash in concrete is presented.Improved workability of fresh concrete, reduction of peak curing temperatures and increase of the denseness of hardened concrete are being recognized as attainable advantages in practice. Also pozzolanic reactivity as protection against reactions with alkali-susceptible aggregates is of increasing interest.There is in research a trend towards more work about the characterisation of fly ashes in relation to chemical composition and mineralogy structure. Also their impact on the rheology of fresh cement paste, on the energetics of the hydrating system and on the microstructure of hardened cement paste is increasingly being studied. More interaction with other branches of materials science is still desirable.The practice-research relations are demonstrated by experience with use of fly ash in the concrete of a major bridge construction in Denmark. Coherent research and development efforts are found commendable.