Experimental study of anisotropic strength characteristics of grouted concrete block masonry

Compared with plain concrete material, concrete block masonry exhibits distinct directional characteristics on account of the different properties of the anisotropy of the block, its component materials and the regular topology pattern. In this paper, the effect of any component is not distinguished and is treated as a whole. By the phenomenological approach, test on the macro-element with macroscopic dimension was conducted for different principal stress ratios under in-plain loading. By the classical anisotropic failure criteria and coordinates transformation, the laws have been achieved by expressing them in terms of principal stresses and orientation of principal stress to material axis. The strength of uniaxial compression inclined to the material axis 20°-70° reduce nearly to 60% of the strength with coincidence of principal stress direction and material axis. The difference gradually diminishes with the two stresses closing to each other. And the orientation of principal stress to material axis has little influence on the compressive strength when the two stresses approach equality.