Lime Activated Fly Ash Paste in the Presence of Metakaolin

The strength and ultrasonic pulse velocity of fly ash paste activated by lime and metakaolin is presented in this paper. Two fly ash pastes were prepared, one without metakaolin and one with 25% of metakaolin to replace the fly ash. Chemical activation was implemented by adding 10% lime (by weight of fly ash and metakaolin) to both pastes. The water-to-binder materials were maintained at a constant of 0.6 for both pastes. The binder consists of fly ash, metakaolin, and fly ash. There is strength enhancement for the paste containing metakaolin compared with the paste without metakaolin. The same trend was obtained for the ultrasonic pulse velocity values.