이산화탄소 및 산소 기반 나노버블워터가 시멘트 모르타르 및 콘크리트의 물리적 특성에 미치는 영향

초록

This study investigated the influence of nanobubble water generated using carbon dioxide (CO₂) and oxygen (O₂) gases on the physical and chemical performances of cement-based materials, including mortar and concrete. Nanobubbles, defined as gas bubbles with diameters of less than 100 nm, exhibit high surface energy, prolonged stability in aqueous environments, and enhanced chemical reactivity. These properties promote accelerated cement hydration and the development of a refined microstructure. In particular, carbon-dioxide-based nanobubble water facilitates in situ calcium carbonate formation within the cement matrix, contributing to microstructural densification and offering a promising route for permanent carbon dioxide sequestration. Oxygen-based nanobubble water was used as the control because of its stable generation and measurable concentration. Mortar and concrete specimens were prepared using nanobubble water with various gas types and concentrations. The stability of the nanobubble water was evaluated using zeta potential and particle size distribution analyses. The mortar tests included flow and setting time evaluations, whereas the concrete tests consisted of slump, air content, compressive strength at different curing ages (3 and 28 d) and rapid chloride ion penetration resistance measurements. The results showed that carbon-dioxidebased nanobubble water effectively accelerated early hydration, improved early compressive strength, and reduced chloride ion permeability, indicating improved long-term durability. In contrast, oxygen-based nanobubble water resulted in moderate improvements in workability and strength development. These results suggest that the incorporation of nanobubble water, particularly carbon-dioxide-based nanobubble water, into cementitious systems can improve the material performance while supporting carbon-neutral construction through integrated carbon dioxide utilization.

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