In plain concrete what is the effective depth value "d"
In plain concrete what is the effective depth value "d"
(OP)
Hi,
In a plain concrete beam, what is the value of the effective depth ? Do we take the full depth of the beam or if the ACI code is limiting us ? I don't see the article. Thanks for helping
In a plain concrete beam, what is the value of the effective depth ? Do we take the full depth of the beam or if the ACI code is limiting us ? I don't see the article. Thanks for helping






RE: In plain concrete what is the effective depth value "d"
The effective depth is defined as "the distance from the extreme compression fiber to the centroid of the longitudinal tensile reinforcement." Therefore, it would NOT be the full depth because the centroid of your tensile reinforcement will be the centroid of the the tensile half of the section.
Thus, your d = 0.75*depth of section
EIT with BS in Civil/Structural engineering.
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
Either way you're right, I forgot about chapter 22 which is all about plain concrete. In there it states that you use the full depth, h, unless you're cast against soil in which case you use h - 2 inches (for the uneven excavation).
EIT with BS in Civil/Structural engineering.
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
The assumption is that you assume linear stress-strain relationship in tension and compression. The code specifies maximum stress values in tension and compression.
For footings poured against soil, h used in calculations should be taken as 50mm (2") less than specified thickness.
BA
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
http://www.nceng.com.au/
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
If you want to see how effective plain concrete beams are take a look at the stone beams on top of the Parthenon. To get a span to depth ratio greater than about 2 someone invented arches.
RE: In plain concrete what is the effective depth value "d"
When designing new concrete members, I would not recommend using the Plain Concrete provisions of the code.
BA
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
I also think this question is pointless (maybe a bug). However pointless or not, I fully understand why gasma1975 raised this question in OP. I was actually totally confused at OP's question in a very special moment that was many years back. And still I wish I can get a nominal correct answer. I see most people in this forum has a (structural) title, I am just puzzled that did you guys never have such a moment that you were asked such question as raised in this post?
RE: In plain concrete what is the effective depth value "d"
Gasma1975
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
RE: In plain concrete what is the effective depth value "d"
As has been noted, if you want to check the capacity of an unreinforced section, use Chapter 22. The bending capacity is based on the elastic section modulus, which is based on the overall depth, "h."
You have multiple book sources showing this? Do you care to post one for us to look at? This seems highly unusual.