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Title |
Sulfate Resistance of Alkali-Activated Materials Mortar
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DOI |
http://dx.doi.org/10.11112/jksmi.2016.20.2.094 |
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Keywords |
알칼리 활성화 결합재 ; 지오폴리머 ; 황산염 저항성 ; 황산나트륨 ; 황산마그네슘 Alkali-Activated Materials ; Geopolymer ; Sulfate Attack ; Magnesium Sulfate ; Sodium Sulfate |
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Abstract |
This paper presents an investigation into the durability alkali-activated materials(AAM) mortar and paste samples manufactured using fly-ash(FA) and ground granulated blast furnace slag(GGBFS) exposed to a sulfate environment with different GGBFS replace ratios(0, 30, 50 and 100%), sodium silicate modules(Ms[SiO2/Na2O] 1.0, 1.5 and 2.0) and initial curing temperatures(23°C and 70°C). The tests involved immersions for a period of 6 months into 10% solutions of sodium sulfate and magnesium sulfate. The evolution of compressive strength, weight, length expansion and microstructural observation such as x-ray diffraction were studied. As a results, as higher GGBFS replace ratio or Ms shown higher compressive strengths on 28 days. In case of immersed in 10% sodium sulfate solution, the samples shows increase in long-term strength. However, for samples immersed in magnesium sulfate solutions, the general observation was that the compressive strength decreased after immersion. The most drastic reduction of compressive strength and expansion of weight and length occurred when GGBFS or Ms ratios were higher. Also, the XRD analysis of samples immersed in magnesium sulfate indicated that expansion of AAM caused by gypsum(CaSO4·2H2O); the gypsum increased up to 6 months continuously.
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