Influence of Texture on Mechanical Behaviour of Basalts

To understand the influence of texture on the mechanical behaviour of basalt, four variants each of vesicular basalt, four variants of amygdular basalt and two variants of porphyritic basalt were investigated in the laboratory. These basalts were obtained from different site locations of the Betwa River basin in central India. These basalts were investigated for uniaxial compressive strength, indirect tensile strength and shear strength parameters (cohesion and angle of internal friction). In addition to the above, wave velocities (compressive and shear), durability and density characteristics were also studied. And, mode of failure of basalts in compression has been discussed. The mineralogical composition of basaltic variants was quantified through an X-ray diffraction method. In comparison, vesicular basalts were inferior in all properties and parameters. And, it was observed that the failure propagated in vesicular and amygdular basalts along the chain of vesicles, whereas in porphyritic basalts, the failure is along the grain boundaries of phenocrysts.