New technique for improvement on reactivity of cement industry wastes

A new technique, in which fly ash was first ground before grinding together with cement kiln dust (CKD), was developed in order to activate reactivity of CKD–fly ash systems. Test results of particle size distribution, rate of heat evolution and compressive strength of mixtures made with the new technique are discussed and compared with those of mixtures made with previous technique, in which CKD and fly ash were ground together without prior grinding of fly ash. The test results showed that CKD–fly ash mixtures made with the new technique exhibited significantly improved performance in comparison with that of mixtures made with the previous process.