Quartz stress-strain curves

Figure 9.4. Stress-strain curves observed by Morrison-Smith et al. (1976) at the temperatures shown with specimens cut from the z-growth region of a single crystal of synthetic quartz (W2 with a water content of l,600-200H/10 Si). Stress normal to (lOTl) confining pressure 300 MPa strain-rate 10 s .

The following subsections are concerned with the grown-in defects in synthetic quartz and the dislocation microstructures associated with the various stages of the creep and stress-strain curves. The microstructural evolution in natural quartz deformed under various conditions of water fugacity, and other experimental variables, will be considered in Section 9.5. 

Figure 9.19. Stress-strain curves for single crystals of natural quartz deformed in buffered assemblies at 1.64 GPa confining pressure, 800°C, and strain-rate of 10 s after 20 hours preconditioning. (From Ord and Hobbs 1986.)...

The previous sections have been mostly concerned with the dislocations and microstructures observed in single crystals deformed to various strains under known experimental conditions. In some minerals, notably quartz and olivine, the macroscopic deformational behavior, as revealed by the creep and stress-strain curves, can be understood in terms of the micro-structural evolution during deformation and, furthermore, certain quantifiable characteristics of the microstructure correlate with the imposed... 

Fig. 6.16 Stress-strain curves for loading cycles a concrete with basalt aggregate, eured in standard conditions, b autoclaved concrete with quartz aggregate. (According to [47])...

Figure 9.14 Stress-strain curves of quartz deformed in compression under a confining pressure of 1.6 C Pa in various buffered assemblies at 800°C and a strain rate of 10 s The effective water content increases from the top to the bottom curve. Data from Ref. [87].

Figure 9.5. A typical creep curve for a single crystal of synthetic quartz (X-507 with 365H/10 Si) with a stress of 140 MPa applied normal to (lOTl) at 510°C. Note the incubation period followed by a region of constant strain-rate. (After Linker et al. 1984.)...

---