Anchor bolt and annularly grooved expansion sleeve assembly exhibiting high pull-out resistance, particularly under cracked concrete test conditions

An anchor assembly adapted to be anchored within a bore-hole defined within a concrete substrate so as to be capable of meeting cracked concrete testing standards, comprising:

• an anchor bolt member having a longitudinal axis and an enlarged head portion disposed upon a forward end portion of said anchor bolt member;
• an expansion sleeve member annularly disposed around said anchor bolt member and having a longitudinal axis, an internal peripheral surface portion, and an external peripheral surface portion;
• and
• a plurality of annular grooves disposed only upon a forward external peripheral portion of said expansion sleeve member, while a rearward external peripheral portion of said expansion sleeve member is non-grooved and solid, such that when said anchor bolt member is moved axially rearwardly through said expansion sleeve member, said enlarged head portion of said anchor bolt member will initially progressively expand said forward portion of said expansion sleeve member so that said plurality of annular grooves will be progressively forced into engagement with internal peripheral side wall portions of a borehole defined within a concrete substrate so as to progressively define a progressively increased area and volume of interference with the internal peripheral side wall portions of the borehole defined within the concrete substrate, and subsequently, said enlarged head portion of said anchor bolt member will progressively expand said rearward portion of said expansion sleeve member so that said non-grooved solid portion of said expansion sleeve member will be progressively forced into engagement with the internal peripheral side wall portions of the borehole defined within the concrete substrate so as to achieve a maximum area and volume of interference with the internal peripheral side wall portions of the borehole defined within the concrete substrate so as to enhance the holding power and pull-out resistance of said anchor assembly with respect to the borehole defined within the concrete substrate;
• wherein said expansion sleeve member is slightly tapered, in a smooth, constant linear manner, along its entire axial extent such that the diametrical extent of the external peripheral wall surface of the expansion sleeve member, at the rear end portion thereof, is larger than the diametrical extent of the external peripheral wall surface of the expansion sleeve member at the forward end portion thereof as considered in the direction in which said expansion sleeve member is inserted into the concrete substrate so as to enhance the pull-out resistance of said anchor assembly with respect to the concrete substrate, and wherein further, said expansion sleeve member is plated with a tin-zinc (Sn—Zn) plating composition so as to achieve predetermined frictional characteristics between said expansion sleeve member and said anchor bolt member.