Evaluation of tensile strength and failure response of geopolymerized rock waste using Brazilian tensile test

Khan A.; Zhang N.; Hedayat A.; Sosa B.; Gelber H. · 55th U.S. Rock Mechanics / Geomechanics Symposium 2021 (2021)

Resumen

Geopolymerization is the process to activate the aluminosilicates in raw materials by alkaline activation to make construction materials, such as geopolymer concrete. Industrial wastes like fly-ash and blast furnace slag and mining industry wastes such as mine tailings in form of crushed rocks are commonly used raw materials for production of geopolymers. Geopolymerized mine tailings have a wide application in building and construction industry. The compressive strength of geopolymer was extensively studied by many researchers; however, the tensile strength remains largely unexplored. In this study, the splitting tensile strength of alkali activated geopolymerized mine tailings was investigated using the Brazilian indirect tensile method along with the digital image correlation (DIC) technique. Sodium hydroxide (NaOH) was used as an alkali activator with molar concentrations of 8M and 10M. Initial water/tailing ratio was kept as 20% and specimens were tested after 7 and 28 days of curing. All the specimens were kept in oven at 75°C for an initial 24 hours and then sealed and cured at room temperature. The compressive load was diagonally applied to the specimens with the constant rate of loading of 2 N/s while the DIC system recorded images every 42 milliseconds. The strain profile on the disk surfaces were captured using the DIC correlation software and the critical tensile strain levels associated with the tensile fracture initiation was identified. Copyright

Instituciones: Universidad Nacional de San Agustín de Arequipa