Geopolymers are inorganic aluminosilicate materials, which have been a great research interest as a material for sustainable development. However, they possess relatively low toughness properties similar to brittle solids. The limitation may be altered by fiber reinforcement to improve their strength and toughness. This research describes the synthesis of bamboo shaving (BS) reinforced geopolymer composites and the characterization of their mechanical properties. The effect of BS content (0–2 wt. %) on the physical and mechanical properties and microstructure of metakaolin based geopolymer paste were investigated. The workability, setting time, bulk density, apparent porosity, thermal conductivity, compressive strength, flexural strength, scanning electron microscopy (SEM), and X-ray diffraction (XRD) of geopolymer paste were determined. The results showed that the workability, setting time, density, and thermal conductivity decreased with the increasing of BS content. The BS content was proportional to the apparent porosity and a good linear relation was found between apparent porosity and BS content. The highest mechanical properties were achieved at an optimum BS content of 1.0 wt. %. The results of microstructural analysis revealed that BS act as inforcing phase in matrix, reducing cracks and making a dense geopolymer, which leads to favorable adhesion of the composites and produces a geopolymer composite with better mechanical properties than that of pure geopolymer. However, when the BS content exceeded 1.0 wt. %, interfacial bonding between BS and geopolymer matrix became less. XRD analysis showed that BS has little effect on the mineral composition of metakaolin-based geopolymer and no new phase is formed.

Bamboo shaving; geopolymer; strength; microstructure; thermal conductivity