Alkalinity and Its Consequences for the Performance of Steel-Reinforced Geopolymer Materials
| Autor: | Koenig, Andreas, Mahmoud, Hitham, Baehre, Oliver, Dehn, Frank |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
geopolymer concrete
Polymers micro X-ray computer tomography (µXCT) steel reinforcement corrosion alkalinity micro X-ray computer tomography (μXCT) Electrochemical Techniques Alkalies Hydrogen-Ion Concentration Coal Ash Article Carbon Polymerization lcsh:QD241-441 ddc:690 lcsh:Organic chemistry Steel Buildings Tomography X-Ray Computed |
| Zdroj: | Molecules Molecules: a journal of synthetic organic and natural product chemistry, 25(10) Molecules, Vol 25, Iss 2359, p 2359 (2020) Molecules, 25 (10), Art. Nr.: 2359 Volume 25 Issue 10 |
| ISSN: | 1420-3049 |
| Popis: | This paper investigates the development of the alkalinity and its impact on carbon steel reinforcement embedded in alkali-activated fly ashes (AAFA) and alkali-activated fly ashes with ten percentage mass (wt%) of blast furnace slag (AAFAS)-based materials (geopolymer&ndash GP). The pH analysis of eluates indicates a remarkable decrease of alkalinity in AAFA and AAFAS in the first hours of the geopolymerization process. Phenolphthalein solution and pore solution tests on concretes also show a sharp decrease of alkalinity with increased Ca content in the binder due to carbonation. Micro X-ray computer tomography (µ XCT) and electrochemical techniques indicate that the changed pH in the GP systems was accompanied by a decrease in the corrosion rates of steel reinforcement when compared to ordinary Portland cement (OPC) systems. In contrast to calcite and vaterite, which were detected in OPC and AAFAS after a carbonation process, only sodium carbonate natron was determined at lower levels in AAFA by X-ray diffraction (XRD). |
| Databáze: | OpenAIRE |
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