Properties of Calcined Clay and Limestone Powder Blended Bio-Self Compacting Concrete

Self-Compacting Concrete is a revolutionary concrete that has taken Europe, the America and Asia by storm following its development by Prof. Okamura’s research team in the late ۲۰th century. Since then, it has been revolutionized into various improved forms either by tinkering with the constituents and mix design towards perfecting it or by use of locally available secondary cementitious materials and fillers that are ecofriendly and economical, thereby reducing the carbon footprint as well as enhancing its properties. This research looks into the possibility of using Microbial Induced Calcite Precipitation on the engineering properties of calcined clay and Limestone powder blended ternary Self-Compacting Concrete, with emphasis on the evaluation of the fresh state properties as well as strength and durability. Calcined clay was used as Supplementary Cementitious Material at ۱۵% replacement of cement and Limestone powder as filler, with Sporosarcina Pasteurii as MICP bacteria at different bacterial cell densities of ۱.۵x۱۰۸cfu/ml, ۱.۲x۱۰۹cfu/ml, and ۲.۴x۱۰۹cfu/ml, (McFarland turbidity scale of ۰.۵, ۴.۰ and ۸.۰ respectively) and calcium lactate (nutrient) concentration of ۰.۵%, ۱.۰% and ۲.۰% by weight of cement incorporated into the ternary blend. The strength is evaluated using compressive strength (at ۷, ۲۸ and ۵۶ days curing) and split tensile strength (at ۷ and ۲۸ days) while the durability characteristics are evaluated using water absorption (۷, ۲۸ and ۵۶ days) and sorptivity (۷, ۲۸ and ۵۶ days) and the microstructure investigated using Standard electronic microscopy. The result indicates an overall improvement in the properties of the Self-compacting concrete.