Need a book? Engineering books recommendations...

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

Re: cantilver conc balcony

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Paul,

I would keep the full length (cantilever and backspan), use small top bars at maximum 6 inch spacing, and provide a saw cut or molded control joint over the support.  You could also add some 2" by 2" WWR over the support and extend say 2 feet each way.  You could also go with adding fibers to the concrete where I would recommend, if you go this route, using one with both polypropylene and steel fibers.  For the concrete you might double check ACI 318-08 Chapter 4 Durability Requirements that may require 4500 psi concrete and w/c of 0.45 which I would recommend anyway.  Increasing the concrete cover to 2 1/2" or 3" might also be warranted however this may make the slab overly thick.

Thomas Hunt, S.E.
Fluor



From:        PFFEI(--nospam--at)aol.com
To:        seaint(--nospam--at)seaint.org
Date:        10/14/2011 06:02 AM
Subject:        cantilver conc balcony




I have an exterior concrete balcony with a 15' cantilever and 10' backspan.  I expect that no matter how thick I make slab I will get deflection and a crack over the support.  would it be best to detail a pour joint over the support or cut a crack control joint to control the crack?  joint could be filled with caulk / flexible joint sealer.
 
Also, project is located on a bluff about 1/2 mile away and 300' above the ocean (Malibu).  For slab exposed as finish, is anything recommend fro rebar protection?  I was thinking 4000 psi conc with w/c = 0.5 max, and 2" cover.  should I include something like xypex in the mix, or increase rebar cover, or am I distant enough from ocean that salt will be a minor issue?
 
Thanks in advance,
 
Paul Franceschi
------------------------------------------------------------
The information transmitted is intended only for the person
or entity to which it is addressed and may contain
proprietary, business-confidential and/or privileged material. 
If you are not the intended recipient of this message you are
hereby notified that any use, review, retransmission, dissemination,
distribution, reproduction or any action taken in reliance upon
this message is prohibited. If you received this in error, please
contact the sender and delete the material from any computer. 

Any views expressed in this message are those of the individual
sender and may not necessarily reflect the views of the company. 
------------------------------------------------------------