Cubes compressibility effects

While considerable work was conducted by Southwest Research Institute (2, 3) to develop sulfur-aggregate mixtures, tests were also conducted on the effects on compressive strength of adding sand to sulfur to determine its utility as a mortar material. Two mortar sands of different particle size distributions were used with the sulfur to produce 1-in. cube compression test specimens. Particle size distributions are presented in Table I. 

As a simple (indeed over-simplified) example, we take (as did Clapp) the case of the alloy CuAu we employ an essentially geometrical treatment of strain and ignore electronic effects (the effect of apbs on the Brillouin zones of the alloy, which controls the scale of the final periodicity). CuAu I has a simple superstructure of the cubic-close-packed (c.c.p.) arrangement of metal atoms in pure Cu or Au metals. In the parent, f.c.c. unit cell alternate (001) A layers of atoms contain exclusively Au and exclusively Cu (Fig. 23). Au is larger than Cu and hence, pmely in terms of size effects, the Cu layers must be under tension and the Au layers under compression if the layers are to be perfectly commensurate (as they are). The size effect is in fact seen, for the structure is metrically as well as symmetrically tetragonal the (now distorted) f.c.c. unit cell is face-centred tetragonal, with da = 0.93s instead of 1.000. In the CuAu II structure this strain is relieved (in one direction only ) by the introduction of apbs at every fifth cube plane normal to the layers (Fig. 24). 

The effect is illustrated in Fig. 5.2 in an experiment where a concrete cube, subject to compression, was tested under a cyclic load. The figure shows the AE rate versus time, and the applied load versus time. 

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