Date: April, 2012
Location: I-75 & 12 Mile Rd in Sterling Heights MI
Contractor: Smith's Waterproofing
Engineer: Michigan Department of Transportation
Concrete bridge columns are an integral part of the integrity of highway bridges that may be damaged by various physical forces including earthquakes and vehicle accidents. Vertical effects on these bridge columns lead to significant variations in axial force demand which can result in fluctuations in moment demands at the face of the bent cap, amplification of moment demands at the girder mid-span, and changes to moment and shear capacity of the column.
In this case, concrete columns were deemed to be fatigued due to deterioration of steel reinforcement.
Concrete Columns were deemed to be fatigued due to deterioration of steel reinforcement. Repair was to wrap columns using 600 gsm carbon fiber wrap utilizing onsite impregnator of epoxy saturant.
Material Used: Fortec 600 gsm unidirectional carbon fiber fabric w/ #4550 Epoxy Saturant and #590 Epoxy paste
Wrapping column with Fortec carbon fiber fabric allowed for minimal road closure as would have been needed with old method of teardown and replacement of column. The #4550 epoxy allowed contractor to cure out in field under difficult weather conditions. With highs in the 60's and lows dipping into the 40's a night curing was a challenge.