Friday, October 14, 2011

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