In this study, the effects of sintering at different temperatures on porosity of materials produced by addition of calcite in fly ash based geopolymers are investigated. For this purpose, geopolymeric compositions are prepared by fly ash (100U) and 20% calcite added fly ash (80U20K). Activating of these compositions with sodium hydroxide(12M) and sodium silicate solutions and then curing of the samples at 80 °C for 24 hours geopolymeric structures are obtained. The produced geopolymeric samples are sintered at 500°C, 700°C, and 900°C temperatures for 30 minutes. The temperature increase rate is 5°C/min. The effects of calcite in geopolymeric materials on sintering behaviour are determined by thermal analysis (DSC). The produced materials are characterized by phase analysis (XRD), porous size (mercury porosimeter), apparent density, open porosity, and water absorption analysis. As the sintering temperature is increased, open porosity values in materials decrease. Emergence of glassy phases such as nepheline by sintering the geopolymeric materials at 900°C, decrease 100U sample open porosity value from %29.78 to 12.30%, 80U20K sample value from %39.23 to 32.65%. Calcite addition to the materials provides porosity in the samples at 900°C, the temperature at which glassy phases emerge
Birincil Dil | TR |
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Bölüm | Makaleler |
Yazarlar | |
Yayımlanma Tarihi | 6 Ocak 2015 |
Yayımlandığı Sayı | Yıl 2014 |