Grouting is an empirical constructional technique aimed at improving poor ground
conditions prior to construction of underground structures through the injection of
cementitious, resinous or chemical grouts. For rock grouting, microcements are often
used as a grout material due to their higher strength gain and lower bleeding potential
compared to Type I ordinary Portland cement. The injected microcement grout flows
through the innate discontinuities present in rock masses and contribute significantly to
their mechanical behavior. The deformational characteristics of geological media are
affected by the subjected strain levels and state of stress and for jointed rocks, the
state of joints (roughness, filling material etc.) also have a significant effect. In this
study, the dynamic properties of microcement grouted granitic rocks were analyzed
using the rock mass dynamic test (RMDT) apparatus. Resonant column tests were
conducted on a regularly spaced, planar jointed granitic rock specimen before and after
grouting to analyze the effects of grouting on the strain-dependent shear modulus and
damping ratio.