Section Modulus - Masonry Wall

[slickdeals]

Is it accurate to calculate the section modulus of a masonry wall for in-plane bending (shear walls) using an equivalent solid thickness and treating it as a rectangular section?

I have looked in NCMA TEK, but do not see any calculations for in-plane section properties.

 

[ToadJones]

I think those properties are listed in the CERM

 

[DaveAtkins]

For in plane section properties, I use just the thickness of the two face shells, and treat it as a rectangular section.

DaveAtkins

 

[slickdeals]

@Dave,
In case of a grouted wall (with say 24" or 16" o.c), that can add up to a significant bump in the section modulus. Do you still only consider face shells?

 

[ToadJones]

They are in the CERM

 

[a2mfk]

Agree with your original method, EST and treat it as rectangular. This is to check the CMU compressive stress right?

 

[ToadJones]

I mean come on guys, why the hell are you ignoring me!
The properties for the section moduli of grouted walls, partially or otherwise, are in the CERM

 

[slickdeals]

@Toad:
The properties in the CERM or any TEK publication is for out-of-plane bending (with walls spanning vertically or horizontally). It is not for in-plane section properties.

 

[slickdeals]

This is mainly to check the P/A + M/S on an unreinforced, partially grouted wall.

 

[ToadJones]

I see, & I apologize.
I hastily read the OP.

Do you mind my asking why it is necessary to calculate this for your application. I don't get into masonry design much.

Thanks

 

[a2mfk]

My bet is its a short shear wall with a nice overturning shear force, then you need to check the T/C couple in the ends of the walls...

 

[slickdeals]

See my response above Toad's post.

 

[ToadJones]

I'd say with 100% conviction that you can account for the grouted cells. You could probably just use the outermost grouted cell in your P/A + MC/I calc and use I=Ad^2 as a conservative check.

 

[DaveAtkins]

If the wall is FULLY grouted, then yes, the width is the full width of the wall. If partially grouted, I conservatively assume only the width of the two face shells are the width.

DaveAtkins