Mixed Alkali Regional Metakaolin‐Based Geopolymer

This chapter examines the synthesis of geopolymer using metakaolin produced from kaolinite extracted from Amazonian soil, and microscopically compared to a commercial, highly reactive, metakaolin-based geopolymer. Scanning electron microscopy was used to investigate the microstructure and the Si/Al ratio. In addition, XRD was used to confirm the formation of geopolymer. Biocomposites have low density, low cost and low energy consumption. Amazonian tropical bamboo species Guadua angustifolia was selected based on abundance, accessibility, mechanical properties, durability and commercial size criteria. Four-year old Guadua culms were collected from a research plantation area14,15 at the National Institute for Amazonian Research (INPA) in Manaus, Brazil, and immersed in water for three days for better machine workability. Tests were carried out on an Instron-4483 testing machine, with 100-kN load cell, at the Mechanical Testing Instructional Laboratory (MTIL) on the Talbot Laboratory of UIUC. The test crosshead speed was 0.010 mm/s. Strain was calculated from crosshead displacement. Fractography of post tested composite samples were performed by SEM to understand the toughening mechanisms that improves the flexure strength of the composite when compared to pure K-geopolymer.