shear repair of p/c box beams using cfrp fabric kydot july 27, 2011 salt lake city, utah kentucky...
TRANSCRIPT
Shear Repair of P/C Box Beams using CFRP Fabric
KYDOT
July 27, 2011Salt Lake City, Utah
Kentucky Transportation Cabinet Kentucky Transportation Center University of Kentucky
RAC/TRB Summer Meeting
Objective Retrofit P/C Spread Box Beams using carbon fiber
reinforced polymer (CFRP) fabric to increase Shear
Capacity
CFRP CLOTH/FABRIC
CFRP Fabric
+ Resin
Steel P
late
(A36 Stee
l)
Ultimate Load = 3.25 kip
1”1”
hCFRP = 0.0066”
wCFRP = 0.0051 lb/ft wSteel = 0.19 lb/ft ≈ 37 wCFRP
hSteel = 0.056”
≈ 8.5 hCFRP
CFRP Fabric vs. Steel
Task #1
Material Testing
CFRP Fabric Test Specimens
Task #2
Beam Testing
45o
Beam Strengthening
Beam Testing
Beam Testing
Task #3
Field Application
Bridge on KY 3297 over Little Sandy RiverCarter County, Kentucky
Shear Cracks inP/C Box Beams
Cracks Growing at an Alarming Rate
SevereShear
Cracks
Original Solution
Replace the Superstructure - Cost: ~ $600,000 - Close Bridge to Traffic
Alternate Solution
Use CFRP Fabric - Cost: $105,000 (Design, Repair, and 3-years Monitoring)
- Bridge Remains Open to Traffic
Placement of CFRP FabricStep 1:Surface
Preparation
Placement of CFRP FabricStep 2:
Crack Injection and Filling of Voids
Step 3:Apply Primer
Placement of CFRP Fabric
Step 4:Apply Carbon
Fabric
Placement of CFRP Fabric
Step 5:CFRP Fabric on Outside Face Painted to Match Concrete Color
Placement of CFRP Fabric
Task #4
Monitoring
Scaffolding Used for Monthly Bridge Monitoring
Bridge Monitoring (10/01 to 12/06)
CFRP Fabric on Inside Faces of the Beams Was Not Painted to
Match Concrete Color
Crack Monitor
No Crack Movement Since Repair Was Completed in October 2001
Crack Monitor on Inside Beam Face
- Cost Effective: $105,000 for Repair vs.$600,000 for Replacement
- Repair is Effective: No Crack Movement Since Repair was Completed in
October 2001
- No Detour- No Traffic Control- No Traffic Disruption
Conclusion
!!!!! HURRAY !!!!!!
Associated Press November, 2001
The State Journal, December, 2001
The Daily Independent
November 2001
Other CFRP Projects in KY 9 Bridges Strengthened with CFRP 3 Bridges Strengthened With Steel FRP
Thank Youand
Have a Nice Day
KY