shear resistence of existing RC beam

[n3jc]

Existing RC beam is 250/800 mm (its not a deep beam), concrete C25/30, reinforcement S400
Design shear force is 140 kN (d from supports)

All design resistance values are according to Eurocodes.

Resistence of concrete section (without shear reinforcement is approx. 85 kN)
Existing stirrups are fi8/200 mm (diameter of rebar is 8 mm) - design shear resistance of stirrups is 120 kN (which is less than design shear force)
I also have bend rebar fi22/750 mm (one bar per cross section)as a tension reinforcement that is bend at 45 degrees.
This rebar also has some shear resistance, but Im kinda wondering if my calculations are allright, since I got that design shear resistance of single bend fi22 rebar at 750 mm has approx 172 kN? (I find that hard to believe)!

I dont know if I should consider shear resistance of stirrups AND bend rebar or NOT. Because stirrups + bend rebar together has 120 + 172 = 292 kN > 140 kN so shear resistancve of beam is OK, BUT
If I dont consider a bend rebar my shear resistance reinforcement is NOT sufficient so in this case I ll reinforce existing beam with FRP (Fiber Reinforced Polymer)

What do you suggest? Should I consider bend rebar or not (i feel uneasy since i got only one rebar in a cross section)

 

[KootK]

I'd include the trussed bars in your shear capacity check. Use whatcha got.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[Klitor]

For what is worth,in older eurocode prenorms,there was a clause that allowed you to use bent bars for up to 50% of the shear force and use stirrups for the rest.
You can still find online a free worked example book using that clause.