RC beam strengthening plates 2

[mobe]

I am currently looking to strengthen an existing RC beam & am considering plating the underside. Looking at the concrete, existing steel & new plate composite action what would be the correct way to consider the shear connection between plate & concrete? If using the standard FAy/I type of approach how would "I" be considered?
Also, adhesive or mechanical connection? I have had problems with the former and heard delamination is a problem
with this & fibre reinforcement.
Thanks in anticipation

 

[graybeach]

Have you checked out ACI 440.2? This is for fiber reinforced polymer strengthing, but it covers the issue of shear in the interface. You may want to consider FRP. There has been a lot of research recently that you can find on the internet. NYSDOT has a "standard special" spec for it.

 

[Qshake]

There are other references out there on plating too. Check out Peter Emmons' Concrete Repair; Newman's Structural Renovation of Buildings and finally if you're in the bridge area, NCHRP 293 has all of the plating information.



Regards,
Qshake

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