Comparison of the microstructure and the compressive strength of two geopolymers derived from Metakaolin and an industrial sludge

The aim of this study is to find out the degree of resemblance between the microstructure of a ceramic industry sludge based geopolymer and Metakaolin based geopolymer, in order to use this type of industrial sludge in some applications as a raw material instead of Metakaolin. The studied sludge is collected from a local industry manufacturing sanitary ceramic products. It 's generated during the treatment of its industrial wastewater. The structural change of geopolymer products is followed by FTIR spectroscopy, XRD and TEM analysis. Compressive strength of geopolymer specimens, prepared from the two raw materials, depends on the Na 2 O/Al 2 O 3 molar ratio. XRD analysis of calcined industrial sludge based-geopolymer and Metakaolin based-geopolymer, confirms the amorphous nature of the new formed phase. TEM micrographs of two kinds of raw materials based-geopolymer reveal one type of reacted region. Infrared spectroscopy shows that the behavior of the calcined industrial sludge vis-a-vis the sodium silicate solution is similar to that of Metakaolin.