ACI detailing of columns 2

[mezzoms]

dear engineers

i have a question about the following paragraphs taken from ACI 318

10.7.4 Offset bent longitudinal reinforcement
10.7.4.1 The slope of the inclined portion of an offset
bent longitudinal bar relative to the longitudinal axis of the
column shall not exceed 1 in 6. Portions of bar above and
below an offset shall be parallel to axis of column.

10.7.4.2 If the column face is offset 3 in. or more, longitudinal
bars shall not be offset bent and separate dowels,lap spliced with the longitudinal bars adjacent to the offset
column faces, shall be provided.


what is cause for the 10.7.4.2? what will happen if the offset is about 4 in and i offset bent the long. bar with condition of maintaining the required slope of 1h:6v ???????????

if i have a beam with depth of 600mm adjecant to the column face that will be offset b 4 in can i offset the bar or have i to terminate it and provide a new dowel ??????


thanks

 

[txeng91]

On the column width, it is saying that if the column offset on either side is 3" or more each side, so 6" total column width assuming they are centered,(ex. splcing from a 24x24 to a 18x18) then you have to use bent dowels at a 1:6 slope to splice the column reinforcement. If it is less than 3" than you can just lap the column reinforcement with a gap, this is a standard detail I see on many concrete buildings. I'm not sure on the second question, what is the code year on these sections you are referring to?

 

[hokie66]

dnlv,

You have it backwards. If the sides are offset 3" or more, you cannot use 1:6 sloped bars.

I am not sure about the condition described in the OP's question. Perhaps he can provide a detail.

 

[dik]

Standard Detail attached:

 

[mezzoms]

dik (Structural)28 Mar 17 02:04
Standard Detail attached:

http://files.engineering.com/getfile.aspx?folder=49537674-f692-45f7-887a-f0

What is the name of this document/book to get it?
Or can you send it to download??
Thanks DIK

 

[dik]

It's a *.dwg file that I made... attached:

The text layers have -txti and -txtm for imperial and metric. Feel free to use, but, check first...

Dik

 

[Ingenuity]

Feel free to use, but, check first...

and mezzoms, you owe dik a virtual beer

 

[Trenno]

Step right up, free details here. FREE DETAILS!

 

[dik]

Ingenuity:

I'll drink to that... come to think of it, I'll drink to nearly anything.

Any improvements or corrections would be appreciated.

Dik

 

[mezzoms]

please my friends

i have attached a pdf with 4 details of columns to explain my first statements in my first post to clear what i want to say and understand


i want to know what are the right and wrong ones ( i recommend detail 2 and 4 to match the ACI318 statement that if i understand it right)

thanks
mezzoms

 

[hokie66]

That is the idea, 2 and 4, that is. You would have to determine whether ld is enough for your particular situation. And the 1:6 rule should be applied to the lapping bars on the sides where the columns align.

 

[dik]

I don't think that detail 1 and 3 are permissible.

Dik