Abstract: A tubular anchoring member having an interior passage is inserted into an anchoring hole of a support structure. The anchoring member has transverse dimensions smaller than those of the anchoring hole so that a clearance is defined therewith. A ring-shaped cap member surrounds the anchoring member at a trailing end thereof, supports the anchoring member, and closes the open end of the clearance. An aperture formed in the anchoring member communicates the interior passage with the clearance. A guide sleeve is inserted into the interior passage until a closed leading end of the sleeve is located in the vicinity of the aperture. An open trailing end of the sleeve is connected to a collapsible envelope which is subdivided into a plurality of compartments, each containing a different component of a multi-component hardenable binder material.