Enhanced Durability and Microstructure of Low Aluminum Fly Ash-metakaolin Based Geopolymer

• 作 者: PingDUAN[1]WeiZHOU[2]ChunjieYAN[1]WenjunLUO[2]
• 机 构: Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
• 出 处: The 14th International Congress on the Chemistry of Cement (
• 发表日期: 2015年期

　　Geopolymer specimens were prepared by combination of fly ash and metakaolin activated by sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solutions.High temperature exposure properties for geopolymer and ordinary Portland cement (OPC) were assessed.Compressive strength, mass lose and thermal stability of geopolymer and OPC were compared.Microstructure formation and development was characterized in terms of pore structure by Mercury intrusion porosimetry (MIP).The experimental results reveal that at elevated temperatures, geopolymer is found to be far superior to that of OPC.Compressive strength development shows a dramatic drop of nearly 100% in OPC paste specimen while fly ash and metakaolin based geopolymer has a strength gain of about 3% after 400 ℃ and a final strength of 46 MPa is recorded after the 1000 ℃ temperature exposure.The geopolymer shows similar mass loss curves with OPC but with relatively lower mass loss.High temperature durability is proved by pore structure formation and development indicated by MIP.