【摘 要】
：
Alkali-activated aluminosilicate material, geopolymer, has been expected to be an alternate material for concrete.In this study, fly ash was activated only by alkali hydroxide solution with autoclave
【机 构】
：
Civil Engineering Research Laboratory, Central Research Institute of Electric Power Industry, 1646 A
【出 处】
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The 14th International Congress on the Chemistry of Cement (
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Alkali-activated aluminosilicate material, geopolymer, has been expected to be an alternate material for concrete.In this study, fly ash was activated only by alkali hydroxide solution with autoclave curing to achieve both high strength and high content of zeolite.Zeolite has cation exchange ability, so the proposed geopolymer material is expected to have high capability in captering hazardous trace elements.The autoclave curing temperature was set at 180℃ for highly production of zeolite.There are suitable range of Si/A1 ratio of amorphous phase and preferable grain fineness of fly ash to obtain enough strength and production of zeolite under constant mixing ratio of fly ash and sodium hydroxide.Gmelinite was the main product in any cases.On the other hand,production amount of Zeolite NAP1, Hydroxysodalite and unidentified product with 9-10℃ broad peak in XRD profile depend upon the properties of fly ash.Compressive and flexural strength showed good correlation with pore size distributing property of hardened materials.High strength specimen obtained less porosity in 1-100μm and much porosity in 0.003-0.1 μm.Cation exchange capacities of powderized specimens were 80-150 cmol/kg.The patition coefficients for cesium were 33-71 L/g, the higher reaction rate of fly ash, the higher absorption capacity.
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