Understanding the effect of curing age on the chloride resistance of fly ash blended concrete by rapid chloride migration test

Based on the RCM tested results, it is found that the effect of curing age condition on the chloride migration resistance is depended on the amount of fly ash incorporated in concrete. Short term curing age can lead to increase the chloride migration coefficient of concrete with low fly ash content. But resistance to the chloride migration can still be enhanced at this curing stage when high percentage of fly ash is supplied. Long term curing age can benefit the chloride migration resistance, regardless of how much fly ash is used in concrete. However, this positive effect becomes less significant when increasing the curing time at the late curing stage. The concrete microstructure is also explored to elucidate the macro-behavior of chloride migration.