Fracture and failure processes of geopolymerized mine tailings under uniaxial compression

Zhang N.; Hedayat A.; Sosa B.; Gelber H.; Cárdenas G.; José J.; Álvarez S.; Edgard G.; Rivera A.; Victor; González J. · 54th U.S. Rock Mechanics/Geomechanics Symposium (2020)

Resumen

Mine tailings that are rich in aluminosilicates can be activated and converted to geopolymers to develop building and construction materials, such as geopolymer concretes and bricks. Geopolymer can be widely used in retaining structures, building constructions, and pavement structures. However, due to the disturbances derived from external loads and the heterogeneities resulting from the internal activation extents, the geopolymerized materials may develop internal fractures and flaws. Therefore, the knowledge of damage, fracture, and failure behavior of geopolymer is critically important for its further re-use and application. The uniaxial compression test (UCT) is widely used to assess the compressive strength of materials as a function of the alkaline concentration. However, the damage and failure mechanisms of geopolymer are largely unexplored and there exist a limited number of experimental and numerical studies exploring these mechanisms. In this study, a series of UCTs were performed on geopolymer specimens to investigate these mechanisms considering different internal and external influential parameters such as the OH-%. Meanwhile, discrete element method (DEM) modeling was conducted to examine the corresponding microscale behavior. The damage pattern, fracture evolution, and failure modes as a result of the internal and external influential factors were studied. In addition, the stress-strain relationships for the geopolymerized mine tailings with regard to different influential factors were compared and interpreted.

Instituciones: Universidad Nacional de San Agustín de Arequipa