The result of eirect and indirect tensile strength experiment applide to gypsum and lime stone by changing the shpae at the displacement rate of 0.05cm/min, and 0.5cm/min is as follows;
Supposing that the displacement rate were slow, the tensile stren...
The result of eirect and indirect tensile strength experiment applide to gypsum and lime stone by changing the shpae at the displacement rate of 0.05cm/min, and 0.5cm/min is as follows;
Supposing that the displacement rate were slow, the tensile strength of rock would be low and if it were fast, it would tend to be high.
The tensile strength value, the experimental part in the shape of column, which is less influenced by the phenomena of a stress concentration is higher then that of notch which is influenced a lot by them.
And the tensile strength, the experimental part in the shape of slender has a middle value between column and notch and the direct tensile strength value is similar to indirect tensile strength value.
In the case of using the tensile strength value of rock when we make a blasting plan, if we use the tensile strength value found by direct tensile strength load which was at high speed to the experimental part in the shape of column, the plans with little probabilities of failure will be able to be made.