Compressive strength and durability performance of limestone calcined clay cement concrete made from selected African raw materials

Abstract

Africa is one of the regions where significant construction will be experienced in future. While the use of Limestone Calcined Clay Cement (LC 3 ) is considered a viable option for lowering costs and environmental impact of concrete, its viability needs to be verified based on performance assessment of locally available constituent materials. In this study, the performance of LC 3 mixes with clinker contents of 45 %, 55 %, and 65 % with four different clays from South Africa and Tanzania, was assessed and compared with two conventional concrete mixes. Overall, it was concluded that, LC 3 mixes are characterised by reduced penetrability , increased electrical resistivity, higher chloride ingress resistance, and increased carbonation rates, indicating superior durability performance for marine exposure conditions. Factors such as the specific surface area of the clay and the alkali contents were found to influence the performance of the system, and these aspects require further study to better understand their influence. • The viability of selected African clays for LC 3 mixes has been verified. • The selected clays produced concretes with adequate strength performance. • The alkali content of the clay has high influence on the performance of concrete. • The LC 3 mixes show superior durability potential for marine exposure conditions.