A rotary mixer with a flat beater was used for mixing. Cement (if applicable), water, and either fly ash or silica fume (if applicable) were mixed for 5 min. After pouring into oiled molds, an external electrical vibrator was used to
A rotary mixer with a flat beater was used for mixing.Cement (if applicable), water, and either fly ash or silicafume (if applicable) were mixed for 5 min. After pouringinto oiled molds, an external electrical vibrator was used to