关键词: 胶结充填体, 尺寸效应, 抗压强度, 破坏模式

Abstract: Size changes affect the mechanical property parameters of the material.As a kind of concrete material，the uniaxial compressive strength of the cube filling body specimens has a significant size effect.Under the consistent conditions for the proportion of cement and tailings，slurry concentration and curing age，the effect of size change on the uniaxial compressive strength of cemented filling body was studied.The VIC-3D full-field strain measurement system was used to monitor the rupture and evolution of the filling body specimen.It was found that the uniaxial compressive strength of the cemented filling body decreased gradually with the increase of the size，reduce nearly half.The peak strain of the specimen decreased gradually with the increase of the size and stabilized at 0.9%.The elasticity modulus and deformation modulus increased with the increase of size.The peak strength of the specimens of the size effect was quantitatively analyzed by size effect degrees.The size effect degree of 200 mm specimen reached 54%.A number of cracks occurred at the surface of specimens with smaller size when it is damaged.With the increase of the specimen size，there was a significant macroscopic failure zone on the surface of the specimen.When the large specimen reached the peak strength，serious damage fractures appeared at the local area，but most of the region did not occur obvious strain changes.

Key words: Cemented filling body, Size effect, Compressive strength, Failure mode