Beneficiated Fly Ash Versus Normal Fly Ash or Silica Fume

The results of this paper indicate that a beneficiated fly ash (BFA) with a low carbon content, very fine particle size, and a more favorable shape of the small spherical particles, could be used instead of silica fume (SF) for high performance concrete. In particular, the BFA-concrete mixture derives more advantage from the use of polycarboxylate-based syperplasticizer (SP), when compared to the SF-concrete. Therefore, when the same SP dosage is adopted, the water-cement ratio as well as the water-binder ratio were lower. The compressive strength tends to be higher when BFA is used instead of SF for the same cost. On the other hand, when BFA is used instead of ordinary fly ash in the manufacture of self-compacting concrete (SCC), there is a significant technical advantage only where a self-leveling concrete is needed.