DESIGN AND DEVELOPMENT OF ADDITIVE FOR CO 2 FIXATION UTILIZING BY-PRODUCT CONTAINING Ca （4） ─EFFECT OF ADDITIVE FOR CO 2 FIXATION USING RAW CONCRETE SLUDGE ON INITIAL HYDRATION REACTIVITY OF CEMENT─

Key Points

• The aim is to design a CO2 fixation additive utilizing raw concrete sludge and assess its impact on cement hydration.
• Evaluated a CO2 fixation additive with a main component of γ-C2S using raw concrete sludge.
• Considered compositions that generate C4AF and C2AS for optimal performance.
• Examined the additive's effects on the initial hydration reaction of cement.
• The CO2 fixation additive inhibits reactions of cement's early-age alite.
• Adjusting gypsum content allows some aluminum ions to form ettringite, reducing reaction inhibition.
• Mortar tests show good strength development before and after carbonation using the adjusted additive.