Capacity of Form-Hanger Anchors in Prestressed Concrete Girders

摘要

A study of the practice of supporting formwork with cast-in-place and welded form-hanger anchors in precast, prestressed concrete girders was accomplished. The study included identification of the types of anchors available for use in Texas, identification of the existing procedures for selection and installation of such anchors, and laboratory testing of 60 anchors of various types in a full-scale girder. It is concluded that while the anchors tested did generally meet manufacturers' specified strengths, some anchor systems tend to fail in a brittle mode, without exhibiting significant deformation prior to ultimate failure. Furthermore, the strength of the various anchors is usually strongly dependent on edge distance, and specifications do not exist to satisfactorily ensure the safe placement and inspection of such anchors. Guidelines, in the form of a draft specification and interim recommendations, are submitted for consideration by the Texas State Department of Highways and Public Transportation.