Workability test method for metals applied to examine a workability measure (plastic limit) for clays

The Küre clay (KC) and the Deresakarı clay (DC), taken from the Söǧüt region (Bilecik, Turkey), were examined by chemical analysis, X-ray diffraction (XRD) and thermal analysis techniques. It was determined that the KC and DC, whose basic clay mineral was kaolinite, contained 37% and 66% free quartz as mass percentage, respectively. The compression and upset tests applied to metals were applied to KC and DC. The KC and DC green bodies were passed through an extruder, and cylindrical clay green bodies having different moisture contents were obtained and used in the experiments. The yield stresses (σ0.2) were determined from the compression tests. Plastic tensile strain limit values (εθ*) were determined from the upset tests. The product of the two characteristic values, σ0.2εθ*, was defined as the workability. The variation of the σ0.2, εθ* and σ0.2εθ* values as a function of the moisture content of the green bodies was discussed for KC and DC. From the maxima of the σ0.2 curves, the optimum moisture percentages were determined as 22.0 and 26.5 for the KC and DC, respectively. These results and the results obtained from the Atterberg and Pfefferkorn tests were discussed comparatively.