Pull-Out Strength of Hooked Steel Fiber Reinforced Geopolymer Concrete

Abstract Pull-out strength of fly ash steel fiber reinforced geopolymer concrete was studied. Fly ash steel fiber reinforced geopolymer concrete was produced by mixing of Class F fly ash which taken from Manjung power station, Lumut, Perak, Malaysia with alkaline activator which are combination of sodium hydroxide and sodium silicate. Steel wool fiber were added into the geopolymer concrete as reinforcement with different weight percentage vary from 0 % - 5 %. Chemical compositions of Malaysian fly ash was first analyzed by using X-ray fluorescence. All geopolymer concrete samples with inclusion of hooked steel fiber with different volume percentage which are 0 %, 0.5 %, 1.0 %, 1.5 %, and 2.0 % were tested in terms of microstructure, flexural strength, flexural toughness, and pull-out strength. Microstructure of steel fiber reinforced geopolymer concrete shows a good degree of bonding between geopolymer binder and hooked steel fibers. Flexural strength of samples increased with the addition of hooked steel fibers until at 3 % and will slightly decrease when amount of fibers addition over than 3 %. Meanwhile, addition of hooked steel fibers shows significantly improvement to the toughness of samples. However, there is no improvement of toughness with addition of fibers over than 3 %. Pull-out strength of samples shows an excellent result where maximum result of 505 N can be achieved that indicates a good degree of bonding between geopolymer matrix and fibers.