Properties of Self-Compacting Concrete Using Multi-Component Blend Binders for CO2 Reduction

Abstract

This paper aims to reduce the quantity of cement used by up to 80% by utilizing industrial by-products. By reducing the amount of cement used, there is an effect of reducing CO2 emissions during cement manufacturing. To reduce the amount of cement used, ground granulated blast-furnace slag (GGBF), fly-ash (FA), and calcium carbonate (CC) were used as substitute materials for cement. CC is a by-product, discharged by collecting CO2 emitted from a coal-fired power plant and reacting with additives. The specific surface area and the average particle size of CC used are 12,239 cm2/g and 5.9 μm (D50), respectively. The viscosity of pastes that contained GGFF and FA decreased by up to 51 and 49% respectively compared to the use of only cement (OPC) paste. However, paste using with CC increased up to 23% in relation to plain. As a result of measuring slump flow, segregation resistance ability, and filling ability to evaluate construction performance, slump flow was reduced by up to 3% (G40F10C30) in relation to plain concrete. Segregation resistance ability of fresh concrete using, GGBF (15, 30, and 45%), FA (10, 20, and 30%), CC (10, 20, and 30%), the time it takes for the slump flow to reach 500 mm, time it takes to through the V-funnel showed a decreasing tendency as the usage of FA increased. However, CC increased with increasing mixing ratio. This trend is, the viscosity increase when CC was mixed in terms of rheology. Filling ability of fresh concrete using GGBF (15, 30, and 45%), FA (10, 20, and 30%) and CC (10, 20, and 30%), the criteria were met, and the average increase was 16% and the maximum was 20% in relation to plain concrete. In the case of compressive strength, the compressive strength at 1 day was found to be an average of 5 MPa when 80% of the cementitious was substituted. At 3 days, at least 8 MPa was measured. The compressive strength at 28 days showed a tendency to decrease as the mixing rate of CC increased, but was measured to be at least 34 MPa. The relationship between compressive strength and splitting tensile strength or elastic modulus at 28 days satisfies the standard range.