CEMP-E
TI 809-02
1 September 1999
Transfer shear, bending, and axial loads between beams and columns and
between beams and walls.
Connections between precast elements, or between cast-in-place concrete elements and
precast elements can include the following types of connections:
Column to foundation
Column to column
beam to column
Slab to beam
Beam to girder
Beam to beam
Slab to slab
Wall to foundation
Slab to wall
Beam to wall
Wall to wall
Details for these various types of connection can be found in the Prestressed Concrete
Institute (PCI) Technical Report No. 2, "Connections for Precast Prestressed Concrete
Buildings".
a. Shear Connections. Shear connections are classified as either "wet" or "dry". Wet
connections use reinforced or unreinforced cast-in-place concrete to form the junction between
members. Dry connections utilize a mechanical anchor, such as bolts or welded metal, to
transfer load. Wet and dry connections use shear-friction resistance to transfer forces. In wet
connections the reinforcing steel placed across the potential failure plane provides the
clamping force needed to provide the shear-friction resistance. The most common type of dry
connection involves embedded plates or other structural steel shapes that are anchored to the
concrete by welded studs, anchor bolts, or expansion anchors. The embedded plates or
structural steel shapes embedded in each of the concrete elements to be connected, are then
connected themselves by weldments or by bolting. Contractors prefer the "dry" type
connections because they are the easiest types to construct. The "wet" type connectors
however are usually the best performers, especially under cyclic loading conditions such as
occur during earthquakes.
b. Embedded Bolt and Headed Stud Anchors. Embedded anchor bolts and headed
studs are commonly used to transfer shear and tension loads between cast-in-place concrete
and precast concrete members and between cast-in-place concrete and structural steel
shapes. Anchor connections should be designed and detailed to assure connection failure will
be initiated by failure of the anchor steel rather than by failure of the surrounding concrete. The
design of anchor bolt connectors will be based on the requirements of FEMA 302, Paragraph
9.2, "Bolts and Headed Anchors in Concrete." Additional information regarding the use of
headed anchor bolts for anchorage can be found in the American Institute of Steel
Construction (AISC) Engineering Journal, Second Quarter / 1983 Report, "Design of Headed
Anchor Bolts," and in the Prestressed Concrete Institute (PCI) Design Handbook. Where
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