Uncommon Type WWF As Calculation 1

[JJBLT]

Hi all,

I am trying to check a roof slab capacity of an existing building designed in 1971. The slab reinforcement was called out "4x10-#1/#8 x 5' WIDE WWF" and "4 Pieces of 4x6 - #2/ 1/4" WWF". With little experience with WWF, I looked up the ACI318 as well as concrete book but hardly find any WWF combination similar to the callouts. Can anyone with experience help me out?

For the callout "4x10-#1/#8 x 5' WIDE WWF", I'm not sure what is #1/#8. I also don't know why it says "x 5'"

For the callout "4 Pieces of 4x6 - #2/ 1/4" WWF", I'm not sure why it calls out "4 Pieces"

My goal is to calculate the area of steel "As" for these two callouts. Please help.

Thanks!!!

 

[jayrod12]

4x10 is the spacing in each direction. #1 #8 is bar sizing I believe. x5' means it is 5' wide rolls.

Again that may be slightly incorrect but I believe that's how it was explained to me once.

 

[TehMightyEngineer]

Jayrod is correct. The 4 pieces means they specified 4 mats.

WWF (or WWR as it's now called) is not much different from rebar calculation wise. Instead of the bars being placed and tied they are placed in welded sheets. They may or may not be deformed which might change development length.

For the 4x10-#1/#8 5' wide WWF you have the equivalent of #1 bars (1/8" diameter) at 4" o.c. with #8 bars at 10" o.c. the other way. The sheet is 5' wide.
For the 4x6-#2/1/4" WWF you have the equivalent of #2 bars (2/8" diameter) at 4" o.c. with 1/4" (2/8" diameter again) bars at 6" o.c. the other way.

From these you can calculate an equivalent reinforcement area by summing the cross sectional area of each "bar" in a unit length.

Maine EIT, Civil/Structural.

 

[JJBLT]

I got it! Thank you Jayrod and Teh for the detailed and fast responses.

 

[LonnieP]

I think (back in the 70's) the #1 & #8 were wire sizes, not rebar sizes. Check with other grey hairs to make sure.

LonnieP

 

[PEinc]

I would be surprised if the WWF had 1/8" (#1) diameter wire in one direction and 1" (#8) wire in the other direction. That would not be welded wired mesh. Wire size is designated by the # sign and a number. For example, #9 wire is often used to bundle items together. Wikipedia has the diameters for various wire sizes.
#1 = 0.2893" = 7.348 mm diameter
#8 = 0.1285" = 3.264 mm diameter
#9 = 0.1144" = 2.906 mm diameter
I searched for "#9 wire diameter" and Wikipedia was the first link listed.

http://www.PeirceEngineering.com

 

[jayrod12]

I would agree that the number is wire size not rebar size.

 

[TehMightyEngineer]

Ah learned something today, good to know that there was a time where #x was not the same as bar size. I should have guessed when they specified #2 and 1/4" called out in the same mesh.

Maine EIT, Civil/Structural.