Bleeding of SCC pastes with fly ash and GGBFS replacement

In this paper, the influences of using large percentages of Class F fly ash (FA) and ground granulated blast-furnace slag (GGBFS) on bleeding capacity, bleeding rate, and other early-age properties of self-consolidating concrete (SCC) pastes were investigated. Seven mix proportions were studied, and they were a control mixture, two binary FA mixtures, two binary GGBFS mixtures, and two ternary FA and GGBFS mixtures. The water-to-binder ratio was kept constant for all the mixes. Target slump flow diameter values were achieved by modifying the superplasticizer dosage. Bleeding, early-age compressive strength, and hydration heat were tested for each mix. The bleeding tests found that, for the studied water-to-binder ratio, both the Class F FA and GGBFS increased the bleeding capacity, rate, and duration of the SCC pastes. Class F FA increased the bleeding properties more than GGBFS did.