A resin bonded mine roof bolt having an elongated rod with a drive head at one end and an expansion anchor threaded onto the other end. A segmented resin compression layer covers a portion of the rod below the expansion anchor. When installed in a mine roof bore hole with curable resin, the resin compression layer mixes the resin and partially fills the bore hole to minimize the amount of resin needed to anchor the bolt. Individual segments of the layer are tapered to create a wedging force on resin with the bore hole. The expansion anchor is expandable upon initial hardening of the resin to tension the bolt.