Direct Solution for Reinforcement Ratio
Direct Solution for Reinforcement Ratio
(OP)
In the Structural Engineering Reference Manual they give a direct solution for solving for rho for beams with tension reinforcing but they do not derive the formula. This seems like a pretty basic step that I should know but I'm having trouble with the math. I think they're using the quadratic formula but I can't seem to figure out how they simplify the formula as shown in the attached image file. Kudos to anyone who can show me the solution! Thanks.
(PS you can ignore the red pen writing)
(PS you can ignore the red pen writing)






RE: Direct Solution for Reinforcement Ratio
Bit difficult to read the above, so see attached file for a PDF copy.
RE: Direct Solution for Reinforcement Ratio
RE: Direct Solution for Reinforcement Ratio
No textbooks required - and the last time I derived it was more than 30 years ago.
This is the simple case.
I challenge you to consider a non-rectangular section with top and bottom layers of rebar with prestressing.