A rock bolt anchor includes a top portion permanently fixed to a bottom portion. The top portion carries a package of resin. A spring-loaded mechanism pressurizes the package and forces the resin out when the package is lanced. The bottom portion main body carries a pair of opposed outer shells in a dovetail joint on opposed tapers. The annulus adjacent to the rock bolt anchor is sealed by top and bottom bulkheads. The bottom portion is threaded onto a rock bolt. A hollow and ported lance is threaded onto the exposed end of the rock bolt. The combination is inserted into a drilled hole and the rock bolt rotated. The lance rises and pierces the package releasing into the sealed annulus. Continued rotation of the rock bolt, forces the main body down and the outer shells up the tapers compressing them against the wall of the drilled hole.