COMPARISON OF POWDER SHEAR TESTS USING A JENIKE FLOW FACTOR TESTER AND A ROTATIONAL SHEAR APPARATUS.

The comparison of shear tests using a Jenike Flow Factor Tester (JFFT) and a Rotational shear Apparatus (RSA) shows different values particularly of the effective and internal angles of friction. A force and momentum balance for the JFFT gives a qualitative explanation for these differences. The ratio R//i/R//a (R//i-inner, R//a-outer radius) of rotational shear cells was varied to evaluate errors arising from the calculation of the mean shear stress from the measured torque momentum. No significant influence of the radii ratio on the mean shear stress was found which may prove the utility of RSA.