Effect of curing temperature on geopolymerization of metakaolin-based geopolymers

• The changing conductivity of geopolymer paste could reveal geopolymerization stage.
• The geopolymerization of metakaolin geopolymer was investigated within 20–100 °C.
• The results indicated that elevating temperature accelerates the geopolymerization.
• The geopolymers present the best mechanical properties cured at about 60 °C.

The effects of different curing temperature (within the range 20 to 100 °C) on electrical conductivity in geopolymerization process were systematically discussed with Impedance Analyzer. The variations of setting time conducted by Vicat apparatus can be described as the influence of curing temperatures on the geopolymerization of metakaolin-based geopolymers. Simultaneously, the impacts on the microstructure and mechanical properties of the geopolymer samples are discussed. The results indicated that elevating curing temperature will accelerate the dissolution, polymerization, reprecipitation processes of the geopolymerization reaction. The optimum curing temperature of geopolymer is about 60 °C at which the geopolymer samples present the best mechanical properties with the compressive strength of 97.95 MPa after cured for 7 days.

Variations of electrical conductivities of the geopolymer slurries against time at different temperature.Figure optionsDownload as PowerPoint slide