Use of CFRP Anchors to Strengthen Lap Splices of Rectangular RC Columns Under Seismic Loading

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Use of CFRP Anchors to Strengthen Lap Splices of
Rectangular RC Columns Under Seismic Loading
InSung Kim PhD, Degenkolb Engineers
Oguzhan BayrakPhD, University of Texas at Austin
James O. JirsaPhD, University of Texas at Austin
Objective

• Strengthen inadequate lap splices of longitudinal
  reinforcement in RC columns built in the 1970s
  and earlier through the use of CFRP jacketing and
  CFRP anchors

Rehabilitation Technique
1. Surface and Anchor Hole Preparation
2. CFRP Jacket Installation
4. Complete Installation
3. CFRP Anchor Installation
Surface Preparation
Test Setup
CFRP Anchor
18 in. x 36 in. Column Section
108 in.
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Test Results

• Effect of Number of Anchors (Full Jacketing)

As-built
Drift Ratio VS Normalized Load(Envelope)
Drift Ratio VS Normalized Load (Cyclic Loading)

• Effect of Jacketing (Partial or No Jacketing)

As-built
Drift Ratio VS Normalized Load(Envelope)
Drift Ratio VS Normalized Load (Cyclic Loading)
Concluding Remarks
CFRP Anchor and Jacket

• Brittle splice failure Yielding
  of column reinforcement
  
  (Ductile failure)
• Improvement of strength and deformation capacity
  after strengthening
• Combination of CFRP jacket and anchors
  CFRP jacket or anchor only
• Possible to apply column with walls using Partial
  or No Jacketing

Better Than