Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Masonry Walls - Horizontally spanning 1

Status
Not open for further replies.

slickdeals

Structural
Joined
Apr 8, 2006
Messages
2,268
Location
US
What is the standard detail adopted when you design masonry walls spanning horizontally between concrete piers (pilasters). I have typically seen joint reinforcing (every 2 courses) extended into the column and the column gets poured after the masonry wall is built.

Are there alternate ways to doing this? What detail would be used if the column is built first, if contractor prefers to do so? I don't like the detail because I am not sure if the wall is "packed" in between piers and arching action developing is questionable. Can the horizontally spanning wall be attached to the column with wall ties? Has anyone specified something like this before?
 
That's pretty much the way to do it with the joint reinforcing taking the moment or with conventional design, the block being laterally supported at the pilasters.

I'll try to dig up some calculations from Glanville's book.

Dik
 
Control joints are often placed at one edge of a pilaster in this case so I would give details for that and design for the wall moment broken there. Unless you have enough reinf to eliminate the joints in the walls.
 
@haynewp,
Can you post a detail? In this current scenario, we are showing double piers (pilasters) separated by a 10mm gap. These double piers are at every 8.5m which matches the column grids. Are you saying that the wall will be designed to act as a cantilever from the adjacent pilaster to the control joint?

Also when you have joint reinforcing every 2 courses, is it fair to assume that the compression block width is the height of two courses and the tension steel is the joint reinforcing? Are there any checks/requirements for the bed joint mortar?

@dik,
Thanks for posting that. I will go through it. I don't think I have ever seen any other textbook or reference that details horizontally spanning walls and their design.

Any info on TEKs or other publications that deals with designing horizontal joint reinforcing to carry moments in horizontally spanning walls?

 
Came from 2 separate texts, Slick...

Dik
 
Slickdeals, the two texts are:

Engineered Masonry Design by Glanville, Hatzinkolas and Ben-Omran, and
Masonry Structures, Behaviour and Design by Drysdale and Hamid.

The earlier one is about 15 years old and may no longer be in print (John Glanville passed away a few years ago). The latter one is about 5 years old; both are extremely good...

Dik
 
The control joint will break the moment continuity. The joint would have to be detailed to transfer shear if you want it to act a a pinned support for the horizontally spanning wall at the control joint locations. NCMA TEK 14-3A gives some guidance on horizontal spanning walls and pilasters (looks like it is based on unreinforced walls though) and TEK 10-2C gives guidance on control joints and shear transfer with details:


It seems like I had tables with joint reinforcing and allowable horizontal spans but I can't seem to find them right now.
 
The double pier arrangement proposed by slickdeals is a good way to detail horizontally spanning walls, while at the same time providing necessary control joints. But I wouldn't even try to span unreinforced masonry 8.5 metres. Wire joint reinforcement is not a substitute for real reinforcement.
 
Hokie,
Control joints are provided at 8.5m o.c. There are intermediate single piers at 2.85m o.c, which is my horizontal span.
 
In that case, I wouldn't provide control joints at those single piers. You want continuity there. But now that I have read your OP thoroughly, I see that you were talking about concrete columns and masonry infill walls. Don't know how I would do that , as I have never done it with horizontally spanning walls.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top