Need a book? Engineering books recommendations...

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

RE: Masonry lap splice (fwd)

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Hugh:

I posed your question to someone that I know on the MSJC and below is his
response.  I have removed names to "protect the innocent", except
mine...since I am not so innocent.  <grin>

HTH,

Scott
Ypsilanti, MI


---------- Forwarded message ----------
Date: Wed, 29 Oct 2003 16:01:32 -0500
To: 'Scott Maxwell' <smaxwell(--nospam--at)engin.umich.edu>
Subject: RE: Masonry lap splice

To not much surprise, this has been a hotly debated item within various code
forums.

It started (innocently enough) with a request from the seismic design
community questioning whether 48 bar diameters was long enough for all
applications where ductility was an issue.  When this topic was researched,
a mode of failure (a virtual splitting of the masonry along the length of
the lap) was identified that was not considered in the development of the
48db equation (which is primarily based on the bond strength between the
reinforcement and the grout).  The research however focused on laps
subjected to direct tensile loading (not flexural as is a more common design
case).  A full copy of the research report can be downloaded at
www.masonryresearch.org <http://www.masonryresearch.org/>

My personal feeling is that the longer lap lengths may be justified when:
1)       the laps are subjected to direct tensile loads
2)       large inelastic deformations are anticipated (i.e., plastic hinge
regions)
3)       no confining reinforcement is present (which may preclude this
splitting phenomenon seen in the research)

The debate on this topic is far from over - and will likely result in
substantial reductions in the required length of lap (as a function of one
or more of the above items).

Hope this helps.  Feel free to share this with your email list.



******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********