Rocks can be tested for uniaxial compressive strength (UCS) using either the stress rate or the strain rate. In both scenarios, the loading rate affects the mechanical and elastic characteristics of a rock sample, including its compressive strength, yield strength, elastic modulus, Poisson's ratio, time at ultimate load, etc., vary with the loading rate. Many researchers worldwide have observed that these properties of the materials differ mostly based on the variation of stress rate or strain rate under the uniaxial compression strength test [Bischoff et al., 1991].
The mechanical and elastic behaviour of artificial rock samples under UCS test at five different strain rates: 10-6 s-1, 10-5 s-1, 10-4 s-1, 10-3 s-1, and 10-2 s-1 has been attempted to be studied in this paper. These tests are carried out by a servo control stiff testing machine of 3500 kN (INSTRON). Mechanical and elastic properties are determined by laboratory tests, and then the relationships of these properties with strain rate are established. Mechanical and elastic properties increase with strain rate in logarithmic relations. However, Poisson's ratio does not show any relationship and does not vary significantly with strain rate. The fracture patterns in artificial rock samples have also been studied in great depth. Type 2 and type 3 fracture patterns in the samples are observed at different strain rates between 10-6 s-1 to 10-2 s-1.
Uniaxial compressive strength, Yield strength, Strain rate, Stress rate, Elastic behaviour
