Message----- From: Arvel L.
Williams, P.E. [mailto:awilliams(--nospam--at)gwsquared.com] Sent: Thursday, May 12, 2005 10:50
RE: Lightweight yet stiff fill ?
foam blocks from Contech. Seen it used on airports over really bad
subsurface soil condition.
alternative is pumice or expanded shale. The unit weight is in the 90s
pcf. Might be expensive either way.
Message----- From: Bill
Allen, S.E. [mailto:T.W.Allen(--nospam--at)cox.net] Sent: Thursday, May 12, 2005 12:24
Lightweight yet stiff fill ?
working on a project where there is going to be an addition to an existing
penthouse. The existing roof is concrete slab over metal joists. The new
slab will be at least 6 inches above the existing roof slab and may be as
much as 12 inches above at the low part of the roof. Due to the loading, I
don’t want to fill the entire space with concrete. I would rather use a thin
slab (4” lightweight; 3,000 psi w/#3 @ 15” E.W. or something close to that)
over some lightweight material. My concern is the stiffness, of course. The
use is residential, so there will not be any heavy loads on the slab, but I
do not want the slab to “settle” too much. My first thought was pearlite or
vermiculite, but I don’t know if either is stiff enough.
thoughts/recommendations would be appreciated.