Internal Curing and Carbon Sequestration Induced by Ground Biochar in a Clinker-Free CaO-Activated GGBFS Binder System = 분쇄 바이오차를 활용한 무클링커 CaO 활성화 GGBFS 결합재의 내부 양생 및 탄소 격리

다국어 초록 (Multilingual Abstract)

This study examines the incorporation of pre-wetted, ground biochar into a clinker-free CaO-activated GGBFS system, highlighting its multi-stage desorption behavior and internal curing benefits. The biochar rapidly released pore-stored water between 1–6 h and maintains moisture beyond 6 h, delaying early hydration by up to 8 h but supplying secondary water that reverses initial strength deficits. At dosages up to 3 wt. %, 28-day compressive strength did not decrease but was instead improved by approximately 2% via this internal curing mechanism. However, a 5 wt. % replacement caused a 5% reduction in strength. The primary hydration products—ettringite, C–A–S–H, Ca（OH）2, and hydrotalcite—remained largely unchanged. The biochar incorporation reduced overall pore volume while keeping pore sizes below 50 nm, and enhanced Ca and Si dissolution of GGBFS. The incorporation of biochar and the proposed cementless binder significantly enhanced carbon sequestration, reducing net CO2 emissions to as low as 29.0 kg CO2 per ton of binder, compared to 637.1 kg for Ordinary Portland Cement （OPC）-based binder. Furthermore, the emission-to-strength ratio was reduced from 12.74 to 0.96 kg CO2 per MPa. These results underscore biochar’s dual role as an effective internal curing agent and carbon-sequestration additive in sustainable clinker-free binders.

목차 (Table of Contents)

• 1. Introduction 1
• 2. Experimental procedures 6
• 2.1. Raw materials 6
• 3. Results 16
• 3.1. Water absorption and desorption of the ground biochar 16
• 3.2. Heat of hydration 19
• 3.3. Strength development 21
• 3.4. XRD 25
• 3.5. TGA 27
• 3.6. MIP 33
• 3.7. ICP-OES and pH measurement 35
• 3.8. Evaluation of carbon sequestration contribution 39
• 3.9. Flowability 41
• 4. Discussion 44
• 5. Conclusion 47
• References 49
• 국문초록 64
• Acknowledgements 66