Abstract:

The experimental tests for limestone specimens at 200 ℃ in uniaxial compression were carried out to study the mechanical effects of loading rates on limestone using the Rock Mechanics Servo-controlled Testing System MTS810, in which loading rate was treated as a variable. The mechanical properties of limestone such as the stress-strain curve, the variable characteristics of peak strength and the modulus of elasticity of limestone were studied under the loading rates ranging from 0.000 5 mm/s to 5.0 mm/s. The results show that (1) With the rise of the loading rates, the peak strength and elastic modulus of limestone increase sharply from 0.000 5 mm/s to 0. 005 mm/s at 200 ℃; bat show downward trend when the loading rates from 0.005 mm/s to 0. 5 mm/s; and show increase trend when loading rates over 0.5 mm/s. (2) The peak strain of limestone shows downward trend when the loading rates from 0.000 5 mm/s to 0.005 0mm/s; however, the peak strain increases slowly when the loading rates over 0.005 mm/s. The result can provide valuable references for the rock blasting effect and the rock engineering stability.

Key words: loading rates, high temperature, mechanical properties, limestone