# Masonry Radius of gyration



## DAVE9999 (Oct 22, 2009)

Is there a table that has this information?


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## vhmehta (Oct 22, 2009)

DAVE9999 said:


> Is there a table that has this information?


Dave,

Those are in the CERM (Civil Engineering manual) appendix 69B, 69C and 69D.


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## DAVE9999 (Oct 22, 2009)

vhmehta said:


> Dave,
> Those are in the CERM (Civil Engineering manual) appendix 69B, 69C and 69D.


I don't have that book, is there any other place I could find this info?


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## bcy (Oct 22, 2009)

DAVE9999 said:


> I don't have that book, is there any other place I could find this info?


you can also find the info from the appendices of MDG 5 (Masonry Designer's Guide, 5th Edition). For Solid grouted masonary wall, r=(t^2/12)^0.5=0.29t, where t is the thickness of the wall.


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## wilheldp_PE (Oct 22, 2009)

DAVE9999 said:


> I don't have that book, is there any other place I could find this info?


Are you taking the exam tomorrow? If so, you are missing the greatest single resource for it.


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## vhmehta (Oct 22, 2009)

wilheldp_PE said:


> Are you taking the exam tomorrow? If so, you are missing the greatest single resource for it.


Dave, Try searching in google.. You may get it... Do not panic so late in the game.. In my first trial eventhough I had the tables I did not need them. Not to say that they are not useful... As wilhelpd told it is important to have it so that you ready just in case.


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## DAVE9999 (Oct 22, 2009)

vhmehta said:


> Dave, Try searching in google.. You may get it... Do not panic so late in the game.. In my first trial eventhough I had the tables I did not need them. Not to say that they are not useful... As wilhelpd told it is important to have it so that you ready just in case.


I asked around here and it turns out we have the MDG, 1993 (doesn't say what edition).


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## Casey (Oct 22, 2009)

DAVE9999 said:


> I asked around here and it turns out we have the MDG, 1993 (doesn't say what edition).


1993 definitely won't be the 5th Edition. I think the 5th came out in 2005 or 2006.

But it is not like the radius of gyration will change with each revision of the code... Masonry blocks are pretty much standard in size and have been for many years...


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## STRUCTURAL (Nov 5, 2009)

DAVE9999 said:


> Is there a table that has this information?


for 8" CMU r = 0.289*7.625 = 2.2 in ......... for 12" CMU r = 0.289*11.625 = 3.36 in ......... for 16" CMU r = 0.289*15.63 = 4.52 in


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## knelli (Nov 23, 2009)

STRUCTURAL said:


> for 8" CMU r = 0.289*7.625 = 2.2 in ......... for 12" CMU r = 0.289*11.625 = 3.36 in ......... for 16" CMU r = 0.289*15.63 = 4.52 in


This is true for 100% solid grouted wall. NCMA publishes a free TEK on this subject, TEK 14-1B

http://www.ncmaetek.org/etek/homefrm_map.c...tymaterials.com

Do you think the MDG-05 is necessary? I took the S1 (and passed) without it, do you think it is critical for the S2?


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