STUDIES
Concrete
Traditionally, research in this area has focused on incorporating metallic nanoparticles into concrete. This study, however, explores the addition of Micro-Nano Air Bubbles (MNAB) into water before combining it with aggregates and cement. Key engineering properties, including compressive and tensile strength, initial and final setting times, and temperature variations during setting, were analyzed. A water-to-cement ratio of 0.6 was maintained, and three specimens were prepared for each mix to ensure data reliability. Findings indicated that MNAB-treated concrete exhibited a 19% increase in compressive strength and a 16% increase in tensile strength. Additionally, the initial and final setting times were reduced by about half, and the hydration temperature was considerably lower compared to standard concrete, highlighting MNAB's potential to enhance concrete performance
Micro-nanobubbles (MNBs) are increasingly used in concrete to enhance properties.
This review shows MNBs can improve concrete’s mechanical strength (up to 31% compressive, 10–20% tensile, 3–34% flexural) and durability, with benefits like higher electrical resistivity, freeze-thaw resistance, reduced porosity (17%), and lower water and chloride absorption (20% at 28 days). While MNBs may slightly reduce workability, these effects are within standard limits. MNBs also improve crack resistance and early-age modulus development. More research is needed on workability, durability, and the environmental and economic impacts of MNB-enhanced concrete.
WMNB reduced setting times, mortar flow, and slump but significantly improved compressive strength, with up to 16% and 7% gains at 7 and 28 days. The optimal water-to-cement ratio was 0.35, yielding peak strength improvements (6%, 18.3%, and 16.3% at 7, 28, and 90 days). Higher ratios lowered compressive strength, and microscopy provided insights into WMNB-induced morphological changes.
Nanobubbles increased calcium silicate hydrate (C-S-H) production and enhanced calcium carbonate (CaCO₃) formation by promoting calcium ion reactions. Using CO₂-rich nanobubble-infused water decreased overall porosity and increased the micropore ratio, while differential thermogravimetry (DTG) and NMR confirmed enhanced cement reactivity. These findings suggest that nanobubbles and CO₂ contribute to stronger, more stable concrete by boosting calcium content and modifying pore structure.
This review explores their production, properties, and impact on concrete. MNBs can improve mechanical properties, enhancing compressive (up to 31%), tensile (10–20%), and flexural (3–34%) strengths, along with durability measures like electrical resistivity, chloride resistance, and freeze-thaw performance. Although MNBs slightly affect concrete workability, they remain within standard limits, and using them with sulfo-aluminate cement further improves flow properties. MNBs also reduce porosity and crack width, increasing resilience. However, more research is needed on their environmental, economic, and large-scale application impacts.