Evaluation of the computer controlled dynamic yield locus tester

The purpose of this study was to further evaluate the computer controlled d ynamic yield locus tester (DYLT) based on the constant volume approach. Thi s was done by comparing the flow parameters of five test materials: (1) BCR limestone, (2) glass fibers, (3) ground silica, (4) microcrystalline cellu lose, and (5) wheat flour, using the computer controlled Jenike tester (CCJ T) and DYLT. Test results showed that the flow parameters, cohesion and ang le of internal friction, measured using the CCJT and DYLT for BCR limestone , glass fibers and microcrystalline cellulose were statistically similar (p > 0.05). Only one flow parameter value, cohesion at a consolidation stress of 10.7 kPa, for ground silica was significantly different (p < 0.05) betw een the two experimental techniques. Three of six flow parameter values, i. e., cohesion and angle of internal friction, for wheat flour were significa ntly different (p < 0.05) between the CCJT and DYLT. These differences are attributed to inconsistent post yield behavior. Minimal differences occurre d between the experimental techniques, CCJT and DYLT, and the published dat a for BCR limestone. (C) 1999 Elsevier Science S.A. All rights reserved.