Here, [[sigma].sub.compression] and [[sigma].sub.tension] represent the compressive and tensile

yield stresses or flow stresses at the given compressive and tensile plastic strains, respectively.

and castor oil derivatives that form physical networks, which produce

yield stresses. Associative thickeners in waterborne paints serve a similar purpose.

Figure 3 shows that the replacement of 10% of Portland cement (by weight) with opoka and dolomite dust additives (Compositions III and VI) reduce the

yield stresses of cement pastes by 9.1% and 21.7%, respectively.

(1), there are six independent anisotropic coefficients in which F, G, H are anisotropic coefficients of the main

yield stresses and L, M, N are anisotropic coefficients of the shear

yield stresses in the principal axes of anisotropy.

The maximum shrinkage stress values from drying were similar to those of relaxed compression

yield stresses at the same temperature and RH conditions.

The

yield stresses were measured by Duke viscometer at 2.5 [s.sup.-1].

Its breaking and

yield stresses were 28 and 32, respectively, with an elongational capability of 672% (ref.

Since grain breakage rotation, grain migration, and grain rotation coalescence events take place during grain refinement by ARB and ECAP whose rates depend on grain curvature or elongation, different material

yield stresses are being reported as shown in Figures 3(a) and 3(b).

Table 3 shows the

yield stresses at low fly ash addition levels.

In elastic deformation region the strain [[epsilon].sub.c] = const, but when

yield stresses are reached some polynomial approximations are determined and integrated with respect to [xi] (Fig.

Unfortunately, accurate measurements of

yield stresses and degrees of thixotropy are difficult and shear histories and other variables impact results.

The engineering stresses, corresponding to that strain at yield, are combined with the engineering

yield stresses from the tensile experiments in Fig.