Potassium‐Based Geopolymer Composites Reinforced with Chopped Bamboo Fibers

Bamboo is a fast-growing, readily available natural material with tensile specific strength equivalent to that of steel (250-625 MPa/g/cm(3)). In the pursuit of sustainable construction materials, a composite was made with potassium polysialate siloxo geopolymer as the matrix and randomly oriented chopped bamboo fibers (Guadua angustifolia) from the Amazon region as the reinforcement. Four-point flexural strength testing of the geopolymer composite reinforced with bamboo fibers was carried out according to ASTM standard C78/C78M-10(e1). Potassium-based metakaolin geopolymer reinforced with 5 wt% (8 vol%) untreated bamboo fibers yielded 7.5 MPa four-point flexural strength. Scanning electron microscopy and optical microscopy were used to investigate the microstructure. In addition, X-ray diffraction was used to confirm the formation of geopolymer.