Abstract
Various mineral and chemical admixtures have been widely added to modern concrete mixtures but few studies have investigated the characteristics of air bubbles in fresh cementitious materials under different admixture combinations. This study aimed to explore the influences of mineral and chemical admixture combinations including one Class F fly ash, three different air entraining admixtures (AEAs), and two various polycarboxylate superplasticizers (SPs) on the formation and stability of air bubbles in fresh cementitious systems. The foam index tests on fresh cementitious paste were utilized to explore the impacts of fly ash, AEA types, and SP on foam ability. Also, twelve fresh concrete mixtures were produced in laboratory, then the air volume content and air bubble spacing were measured within 60 min to assess the air bubble stability. Test results suggested that adding fly ash decreased the foam ability of AEA, while the SP addition improved the foam ability. The neutralized vinsol-resin based AEA1 had a higher foam ability than synthetic AEA2 and AEA3. The foam index of paste with SP addition showed a higher correlation with the AEA dosage for fresh concrete than those without SP addition. The air bubble stability in fresh concrete was highly affected by the admixture combinations. Overall, neutralized vinsol-resin based AEA1 produced more stable air bubbles than synthetic AEA2 and AEA3.
| Original language | English |
|---|---|
| Article number | 107264 |
| Journal | Journal of Building Engineering |
| Volume | 76 |
| DOIs | |
| Publication status | Published - 1 Oct 2023 |
Keywords
- Air bubbles
- Air entraining admixtures
- Cementitious materials
- Fly ash
- Foam index
- Superplasticizers
ASJC Scopus subject areas
- Civil and Structural Engineering
- Architecture
- Building and Construction
- Safety, Risk, Reliability and Quality
- Mechanics of Materials