Acquirement of geopolymer and the effect of cation, pH and curing conditions on the properties of geopolymers

In this thesis, geopolymers were obtained by using a fly ash being a by-product of Çatalagzi Power Plant. Sodium silicate, sodium hydroxide and potassium hydroxide solutions were used as alkali activation solution in the experiments. The effect of curing conditions on the properties of geopolymer samples were investigated. The samples were aged for 7, 28 and 90 days in the laboratory. Compressive strength tests were performed on all the specimens. 28 days aged samples were used for microstructural and morphological analysis. Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffractometry (XRD) and Scanning Electron Microscope (SEM) techniques were used to investigate the microstructure of the mixtures. The maximum compressive strength was obtained as 51.45 MPa for the sample synthesized with 12M potassium hydroxide and aged for 28 days. FTIR spectra indicated the fingerprint of geopolymers observed in the region of ~950-1200 cm-1. XRD spectrums showed that geopolymers consisted quartz and mullite crystalls. In SEM images, geopolymeric gel phases were observed.