Calcined kaolinitic clay as a supplementary cementing material and its pozzolanic effect on concrete blends characteristics (Part I)

The calcined kaolinitic clay (CKC) was investigated as a supplementary cementing material to assess its effect on the characteristics of concrete. The experimental protocol included optimization of the mixes of CKC/OPC containing 5, 10, 15, 20, 25, 30 and 35% CKC for production of hardened concrete. An evaluation of the use of CKC which contains about 79% of kaolinite mineral in south Sinai quarries in concrete fabrication. The objective of this study is to deliver an overview on CKC utilized in concrete modification. The physical and chemical characteristics of CKC were assessed. The compressive strength and slump of concrete was tested and discussed. The findings suggest that adding CKC to concrete enhances certain characteristics, particularly mechanical capabilities. For optimal performance, the right dosage ranged is between 10 to 20% by weight of the binder. The optimal replacement ratios for cement with CKC was 10% and 15%, which improved the compressive strength by an average of 120.8 and 118.7% respectively at the age of 28 days compared to the control mix. Assessment of the optimal dosage out of the two ratios (10 & 15%) requires a study of their fulfillment of many characteristics as well as their effect on durability and sustainability and their efficiency in facing harmful elements and media. And then determine the best ratio from the technical and economic point of view.