The Effect of CKD Fineness for Karbala Cement Plant on the Engineering Properties of Cement When add it as a Partial Replacement

Cement kiln dust (CKD) is a waste of cement manufacture. The disposal CKD management has becomes an environmental challenge. In order to overcome this problem, researchers are carried out to find out active means to utilize it in various applications .One of these applications is adding it as partial substitution of cement. The aim of this study is investigating the effect of CKDs fineness on the engineering properties of cement, when utilized as a partial replacement. the CKD was grind by jet mill  and classify into 4 groups according fineness (3000 , 6000  , 8000 ,10000 ) cm2/gm  then prepared blends with (5 ,10 , 15 , 20 , 25 , 30 , 35  and 40) %  replacement by CKD for each fineness ,.The results showed  that  increasing of fineness lead to increasing of water demand for consistency,. Setting time(initial and final) retarded with increase fineness of CKD, and the compressive strength of samples contain CKD up to 20% in fineness more than  6000 cm2/gm are enhanced.  These results may came from the increasing specific area activity of CKD compounds which affected on cement hydration and improve in the cement hydrated particles  packing and more denser and compact of cement hardened. Keywords: Cement, CKD, fineness, consistency, setting time, compressive strength, Karbal