- #1

emilyy__

- 1

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## Homework Statement

For the reinforced concrete T-beam find what axial torque would cause a shear stress of v

_{t}= 0.37 N/mm

^{2}to develop, and so make additional torsional reinforcement necessary according to BS 8110. Use the method indicated in Clause 2.4.4 of BS 8110 of distributing the torque in proportion to the h

_{max}.h

_{min}

^{3}values for the component rectangles.

The T-beam is symetrical with dimensions: 850mm wide, 150mm deep flange, 250mm wide, 300mm deep web.

Ans. (5.4 kNm)

## Homework Equations

v

_{t}= 2T / (h

_{min}

^{2}(h

_{max}- h

_{min}/3))

T

_{n}= T ((h

_{min}

^{3}.h

_{max})

_{n}) / (Ʃ(((h

_{min}

^{3}.h

_{max}))

## The Attempt at a Solution

I split the T-beam up into 3 sections; 250 x 450 mm, 300 x 150 mm, 300 x 150 mm

However, I don't know how to find T given v

_{t}. The second equation above for T

_{n}could be rearranged to give T in terms of T

_{n}and then substituted into the first equation so that it can be solved for each component rectangle. However, I don't know how/if v

_{t}needs to split for the three component rectangles, or if this is even the correct way to solve this problem.

My lecturer is away for a few days so I currently can't go and ask him for advice.

Thanks for any help that can be provided.