Experimental study of non-elastic response of natural stone - sandstone - during Schmidt hammer rebound hardness test
Abstract
Determination of rebound hardness by the Schmidt hammer is considered to be non-destructive test which can be used for the evaluation of some rock mechanical properties of tested material. This paper focuses on the examination of assumed non-destructive character of this test method.
Experimental set-up was designed in order to allow study of possible brittle damage phenomena due to the impacting plunger of the Schmidt hammer. These phenomena were studied by using microscopic methods and computer-assisted image analysis.
Based on the results of tests performed on selected clastic sedimentary rocks – sandstones – it can be concluded that Schmidt hammer does not present non-destructive method. Damage of material encompasses formation of crater, damage zone and microcrack formation.
The overall pattern of damage caused by the Schmidt hammer is comparable with this caused by static indentation test methods.