ROCK QUALITY TESTS.
a. Standards. Quality is normally evaluated by visual examination of
the state of weathering and number and condition of discontinuities. RQD
provides the best currently available basis for establishing overall rock
quality. See Chapter 1 for additional guidance regarding the evaluation of
rock quality using RQD. Relative measurements of rock quality can be made
by comparing ratios of field values of compression or shear wave velocities
to laboratory values (see Chapters 1 and 2).
b. Aggregate Tests. While intended for roadway construction and
asphalt and concrete aggregates, there are several standard tests which
provide methods for measuring certain aspects of rock quality (see Table 9).