It　is　necessary　to　quantify　the　amount　of　delamination　present　in　load　bearing　rock　bolts,　as　small　amounts　may　be　deemed　acceptable　and　large　amounts　may　lead　to　catastrophic　failure.　In　this　work,　a　semi-analytical　FEM　model　is　used　to　calculate　the　theoretical　wave　structures　for　a　rod　embedded　in　concrete.　A　qualitative　relationship　between　percent　delamination　and　wave　reflection　energy　is　demonstrated.　It　is　shown　that　with　the　proper　selection　of　inspection　parameters,　it　is　possible　to　inspect　large　lengths　(10+　ft.)　of　embedded　rod　using　an　ultrasonic　guided　wave　pulse-echo　technique.　©　2006　American　Institute　of　Physics.