Effects of silicafume and fly ash on properties of alumina cement

Alumina cement which was used in this investigation contains about 56% of Al2O3 in the component. Early compressive strength alumina cement at 1 and 3 days can be achieved of 85% compressive strength value at 28 days. After a long period of hydration, the compressive strength of alumina cement harder decreased due to the releasing process of aluminum hydroxide [Al(OH)3] to the outside environment [1, 4,11]. To improve and maintain the long lasting compressive strength of alumina cement harden, new binders would be created SiO2- Al2O3 and among CaO-SiO2-Al2O3. The new binders would exist sustainably in the cement harden as a result of the chemical reaction between the product of hydrated cement called gel [Al(OH)3] with micro silica (amorphous SiO2) [4]. This report demonstrates the result of the investigation which is about the effect of silica fume and fly ash on alumina cement.