Damage evaluation of concrete using iron ore tailings as aggregates under uniaxial cyclic compression

Abstract

Using iron ore tailings (IOTs) as the main aggregate for concrete will not only save crushed stone mining but will also reduce the environmental impact of IOTs. A discrete element model of concrete with realistic IOTs shape was developed using particle flow coding 3D technique. The accuracy of the numerical model was verified with the laboratory uniaxial compressive test results, and the damage of concrete with IOTs of 40% under different working conditions, including stress amplitude or maximum stress in a cycle and the number of cyclic loadings, was also observed in detail. Combining the quantification of damage particles estimation, the macroscopic and microscopic damage mechanism of concrete under cyclic loading was revealed from the perspectives of both IOTs content and particle size. The results show that the maximum stress of cyclic loading is a more important factor than the stress amplitude to control the number of fractures generated. Although the increase of IOTs content can improve the compressive stress of concrete, the reduction of IOTs particle size can curb fracture formation.

Graphical abstract