Simplify Steel reinforcement details for Reinforced Concrete Beams

[keewan]

Hi Guys

We all know that we can calculate shear at different locations then assign different link to every area according to shear forces, what I am looking for what is the approximate distance from face of support to calculate shear for second area(assume beam is divided into two zones of links and the first area will be near support),,(I need the best practice)

For moment as well where it is approximately convenient to cut 3/4 of bottom steel (As per ACI 1/4 OF steel should be continuous ), without calculations

So what I am looking for basically after getting my analysis data from Etab, I need a simplified method to make steel details without going in ACI details(Just calculate steel at major points the use simplified method)

Thank you all

Please help me with this because it is important to me

 

[BUGGAR]

I'm not totally sure what you are asking but in heavy marine works (piers, wharves, Navy projects), we generally compute positive and negative steel at the worst points and run it continuous throughout. Sometimes we design the end span steel for the higher end span moments, but we try to keep all the rest of the main reinforcing the same sizes and quantities. Stirrups have generally only two spacings, 3" at and extending from the supports for a distance, then equal uniform spacing throughout the rest of the span. Steel material costs are higher, labor costs are lower, and some engineers believe a uniform strength throughout will yield a more survivable structure under catastrophic loadings (the Navy worries about such things).

 

[MacGruber22]

As per ACI 1/4 OF steel should be continuous

That is a minimum for general structural integrity. However, I engage in nearly the same practice as BUGGAR for typical buildings. It also minimizes construction mistakes.

"It is imperative Cunth doesn't get his hands on those codes."

 

[KootK]

For flexural bars above grade, most buildings firms' typical deatail shows the bars following ACI's simplified cutoff guidelines for one way slabs. The main exception seems to be grade beams where all rebar is run all the way through. I've always assumed that's related to concerns over frost heave and expansive clays.

For stirrups, I'll open up a tight spacing at the quarter points and do my best to maintain symmetry.

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.

 

[keewan]

Thank you all,

Kootk, just to make things clear, The ACIs Simplified cutoff are clauses dealing with development length, integrity requirements ,etc (Right. this what you meant)

Thank you

 

[KootK]

No, there's a table that presents simplified information in graphical form. A better version for you might be ACI 315 however. An excerpt is shown below.

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.

 

[keewan]

Thank you