Characterisation at the Bonding Zone between Fly Ash Based Geopolymer Repair Materials (GRM) and Ordinary Portland Cement Concrete (OPCC)
| Autor: | Mohd Fadzil Arshad, Remy Rozainy Mohd Arif Zainol, Marcin Nabiałek, Muhammad Faheem Mohd Tahir, Jerzy J. Wysłocki, Andrei Victor Sandu, Mohd Mustafa Al Bakri Abdullah, Katarzyna Błoch, Warid Wazien Ahmad Zailani, Rafiza Abd Razak |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Scanning electron microscope microstructure 0211 other engineering and technologies Sodium silicate 02 engineering and technology lcsh:Technology Article law.invention chemistry.chemical_compound law 021105 building & construction General Materials Science lcsh:Microscopy geopolymer lcsh:QC120-168.85 Calcium hydroxide lcsh:QH201-278.5 lcsh:T 021001 nanoscience & nanotechnology Microstructure Geopolymer Portland cement fly ash chemistry Chemical engineering Sodium hydroxide lcsh:TA1-2040 Fly ash lcsh:Descriptive and experimental mechanics bonding zone lcsh:Electrical engineering. Electronics. Nuclear engineering 0210 nano-technology lcsh:Engineering (General). Civil engineering (General) lcsh:TK1-9971 |
| Zdroj: | Materials Volume 14 Issue 1 Materials, Vol 14, Iss 56, p 56 (2021) |
| ISSN: | 1996-1944 |
| DOI: | 10.3390/ma14010056 |
| Popis: | In recent years, research and development of geopolymers has gained significant interest in the fields of repairs and restoration. This paper investigates the application of a geopolymer as a repair material by implementation of high-calcium fly ash (FA) as a main precursor, activated by a sodium hydroxide and sodium silicate solution. Three methods of concrete substrate surface preparation were cast and patched: as-cast against ordinary Portland cement concrete (OPCC), with drilled holes, wire-brushed, and left as-cast against the OPCC grade 30. This study indicated that FA-based geopolymer repair materials (GRMs) possessed very high bonding strength at early stages and that the behavior was not affected significantly by high surface treatment roughness. In addition, the investigations using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy have revealed that the geopolymer repair material became chemically bonded to the OPC concrete substrate, due to the formation of a C&ndash A&ndash S&ndash H gel. Fundamentally, the geopolymer network is composed of tetrahedral anions (SiO4)4&minus and (AlO4)5&minus sharing the oxygen, which requires positive ions such as Na+, K+, Li+, Ca2+, Na+, Ba2+, NH4+, and H3O+. The availability of calcium hydroxide (Ca(OH)2) at the surface of the OPCC substrate, which was rich in calcium ions (Ca2+), reacted with the geopolymer this compensated the electron vacancies of the framework cavities at the bonding zone between the GRM and the OPCC substrate. |
| Databáze: | OpenAIRE |
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