Cement Kiln Dust (CKD) is a by-product generated throughout the production of Ordinary
Portland Cement (OPC). It is normally emitted to the atmosphere or converted into liquid
and subsequently drained out as effluents to landfills and wastage areas. It impacted human
health and the environment negatively. However, it can be utilized in concrete as raw
cement replacement materials due to its engineering properties which work as an alternative
binder of OPC in addition to that it has benefits in creating economic and environmental
advantages. This study aimed to modify CKD and investigate the chemical composition
of normal-CKD and modified -CKD accordingly. The term modified noted that CKD has
gone through a process of modification using heating process. The reactivity property of
CKD was investigated using pH analysis. Then, mix proportions of different percentage
of normal-CKD and modified -CKD were developed to study the addition effects on
the compressive and flexural strength for different curing period. The trend of strength
development over the addition of CKD was also analyzed. OPC was replaced by CKD at
0% and successively increased by 10% to 100% through binder weight (OPC). A fixed
amount of water to binder (W/B) with a ratio of 0.45 was used for all hybrids. The mixes
were formed into the specimen and tested for compressive strength and flexural strength at
7, 14 and 28 curing days. The medium particle size of CKD used was less than 10μm. The
results of compressive and flexural strength showed that modified-CKD resulted in better
properties and 10% replacement showed
the maximum values of compressive and
flexural strength as a result considered best
percentage replacement in agreement with
its noteworthy results.