ISSN: 1813-0410

Keywords : Calcined Fly Ash

Effect of Calcined and Non Calcined Fly Ash Addition on The Strength of Concrete

Huda N. Kalifa; Omar Jalaa Yahya; Younes Mohsen

journal of kerbala university, Volume 10, Issue 4, Pages 141-148

The present work studies the effect of calcination of the fly ash that added to the concrete to enhance its strength. The fly ash added to the concrete batch in different weight ratios 20, 25, and 30 %. The fly ash added in two groups, group1: Fly ash without firing (Calcination) with particle size ranging from 0.425-1.18 mm. while group 2: Fired (calcined) fly ash at 700 ºC for 4 hours. The X-ray diffraction for calcined fly ash shows that the organic compound shown in the non calcined fly ash was disappeared and the main compounds was silica and millite. Slump test was achieved for the fresh concrete with the addition of calcined fly ash, which shows a clear reduction. The absorption of water during curing was reduced by calination the added fly ash. Also the strength of concrete was enhanced in the case of calcination the added fly ash more than in the case of adding non calcined fly ash.