| 摘要 |
A depth-insensitive concrete fastener system is provided for securing roofing insulation materials to concrete roofing or decking. The concrete roofing or decking substructure is provided with a pre-drilled hole or bore having a predetermined diametrical extent. An anchor bolt fastener comprises a head portion, a pointed tip portion, and a shank portion interconnecting the head and tip portions. The shank portion has a first relatively smooth shank portion disposed adjacent to the head portion and extending toward the tip portion, and a second ribbed portion disposed adjacent to the tip portion and having an axial extent which is only a fractional portion of the entire axial extent of the fastener. The diametrical extent of the first smooth shank portion is less than that of the pre-drilled hole or bore defined within the concrete substructure, whereas the diametrical extent of the second ribbed shank portion is greater than the diametrical extent of the pre-drilled hole or bore defined within the concrete substructure. Therefore, when the anchor bolt fastener is impactly driven into the pre-drilled hole or bore of the concrete substructure, an interference or friction fit is defined between the anchor bolt fastener and interior sidewalls of the concrete substructure defining the pre-drilled hole or bore only along the axial extent of the second ribbed shank portion of the bolt fastener. Consequently, the fastener system is rendered depth-insensitive in that regardless of the depth to which the anchor bolt fastener is driven into the concrete substructure, the installation force does not increase beyond a predetermined limit. A roofing washer element may be pre-assembled upon the anchor bolt fastener as a result of being captured between the head and second ribbed shank portions of the bolt fastener.
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