Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Min. masonry reinf

[Subject Prev][Subject Next][Thread Prev][Thread Next]
This is a little late to bring up in this thread, but here goes:

In a seminar put on by our local concrete association on concrete masonry,
an masonry consultant with the portland cement association recommended that
two re-bar never be used in horizontal applications in an 8" cmu wall unless
they are stacked vertically (one above the other in the block). His
explanation was that in many applications the bars create congestion and the
risk is high that the block will not be fully grouted. In the u-block used
for many lintels, there is not a lot of space in the bottom of the block. 

Do those of you with inspection experience in cmu construction find that
2-#6 bars placed horizontally can be reliably grouted?


> -----Original Message-----
> From:	Bill Sherman [SMTP:SHERMANWC(--nospam--at)]
> Sent:	Friday, December 04, 1998 4:58 PM
> To:	seaint(--nospam--at)
> Subject:	Re: Min. masonry reinf
> Thanks to all who responded to my question on minimum masonry
> reinforcement
> - 
> it sounds like maximum spacing of vertical cells is most economical if 
> partially grouted.  The suggestion of 1-#6@48" vertical and 2-#6@48" 
> horizontal sounds like a good solution for the typical application. 
> "And now for the rest of the story" - my project is in Massachusetts.  Its
> seismic zone is more like UBC Seismic Zone 2A but the Massachusetts State 
> Building Code requires masonry shear walls to be reinforced consistent
> with 
> UBC's Zone 3 requirements.  Also, we are using Korfil Hi-R 12-inch masonry
> block - this is an insulated block system which incorporates rigid
> insulation 
> within the cells and precludes two mats of steel.  We currently are
> proposing 
> to use 1-#6@32" vertical and 1-#6@48" horizontal.  Fully grouted may be a
> good 
> idea here.   
> Regarding Harold's question on experience with full vs partial grouting, 
> outside of the west coast I haven't encountered any regions in which fully
> grouted CMU is considered "standard".  I normally use partially grouted
> except 
> when "by judgement" the amount of grouted cells warrant fully grouted CMU.