mayur
Civil/Environmental
- Jun 2, 2001
- 4
I have a question regarding the composite deck theory.
Metal pan (18GA) of 5'X16' size(consider as a stair landing with live load of 100 psf)with deformed welded bar(#4,10" O.C parallel to 5'-0" side) could be considered as composite deck or not?
This landing has clear span of 5'-0" and has support at every 4'-0" (i.e. stair stringer extends underneath the landing pan).
Q-1:--light weightConcrete depth is about 2 1/2" without any kind of reinforcing steel (of course it has welded rebar on the metal pan)could be consider as a composite structure. Is there any valid theory exist to prove this?
Q:-2 If the design of stringer meets the max. deflection criteria, and after the concrete placement before full load application concrete develops severe cracks (some like 1/8" wide) over the stringer supports and diagonal
cracks.--What is the reason?
Q:-3 Typ. tread of stair (4'-0" long X11"-0" wide) has a crack in the center of each trade. what could cause this kind of cracks. Is it the deflection of the stringers or concrete or poor design.
Any input regarding these questions would be appreciated. Thanks.
Metal pan (18GA) of 5'X16' size(consider as a stair landing with live load of 100 psf)with deformed welded bar(#4,10" O.C parallel to 5'-0" side) could be considered as composite deck or not?
This landing has clear span of 5'-0" and has support at every 4'-0" (i.e. stair stringer extends underneath the landing pan).
Q-1:--light weightConcrete depth is about 2 1/2" without any kind of reinforcing steel (of course it has welded rebar on the metal pan)could be consider as a composite structure. Is there any valid theory exist to prove this?
Q:-2 If the design of stringer meets the max. deflection criteria, and after the concrete placement before full load application concrete develops severe cracks (some like 1/8" wide) over the stringer supports and diagonal
cracks.--What is the reason?
Q:-3 Typ. tread of stair (4'-0" long X11"-0" wide) has a crack in the center of each trade. what could cause this kind of cracks. Is it the deflection of the stringers or concrete or poor design.
Any input regarding these questions would be appreciated. Thanks.