The geopolymerisation of aluminosilicate materials such as fly ash has been a radical change in construction material\u27s chemistry and composition, compared to the portland cement-based concrete calcium silicate-hydrate chemistry. The adoption of fly ash in concrete industry is a good use of by-product ashes to reduce emissions of the greenhouse gas implicitly. However, in this research, the replacement of portland cement by fly ash is 100%, which makes it a zero-cement concrete with no proprietary chemical additives.
Geopolymer concrete (GC) is a revolutionary synthetic material that combines sustainability and high engineering properties, and it is relatively cost-effective compared to portland cement-based concrete, its traditional competitor. Limited research on the structural performance of GC versus the microstructural and material properties has been conducted until now, thus this research focuses on the shear behavior of fly ash-based geopolymer concrete. The main three factors that affect the shear strength are dowel action, shear reinforcement ratio, and shear span-to-effective depth ratio. The experimental program consists of six beams: one Conventional Concrete (CC) beam and five Geopolymer Concrete (GC) beams. Two beams had no stirrups and different flexural reinforcement ratio (ρω), two beams had different shear reinforcement ratio (different stirrup spacing, s) and one beam had higher shear span-to-effective depth ratio (α/d). All the beams failed in shear except two beams; one had higher α/d ratio and one had smaller s. These beams failed in flexural-shear mode. All the GC beams showed high shear strength --Abstract, page iv
