slab
slab
(OP)
what if a one way slab design used in actual instead of two way (the slab should be designed as 2way)
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
Download nowINTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: slab
RE: slab
RE: slab
RE: slab
RE: slab
RE: slab
RE: slab
RE: slab
http://www.nceng.com.au/
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
RE: slab
From the Ground Floor Framing Plan you provided it is 2-way slabs supported by beams in 2 directions. Supported by columns at intersection of alpha-numerical grid lines, and type C1A "columns over" at some perimeter grid locations that evidently support a roof of some type.
The slabs should be designed with reinforcement in both directions, and provide sufficient capacity for flexural actions in both top and bottom of the slab. Check your applicable building/concrete code for termination and curtailment of rebar to for positive and negative bending, in both directions.
The framing plan is obviously not showing reinforcement, but the arrows in 2 directions adjacent to the slab designation "S1" indicates that 2-way slab action is being considered. Hopefully there is a reinforcement plan/layout drawing or at least a schedule of rebar, each way, T&B.
A 180mm column is very thin. Going to be tough to make vertical splices and concrete cover work and still place concrete.
And the "B1" beams are only 200mm wide - again, going to be tough to make such narrow beams "constructible".
Not sure what "CHB" walls are - concrete hollow block? If so, the load tributary to the walls (from roof plus self weight) need to be included in the design of the ground floor beams where shown, eg at grid B2.
RE: slab
The 1400 column height referred to is from foundation to ground floor, not ground floor to roof.
RE: slab
http://www.nceng.com.au/
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
RE: slab
The only remedy that I can think of is to possibly detail your floor finish to "float" somehow if it's sensitive.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: slab
RE: slab
RE: slab
Okay, but exactly what reinforcement got placed to the slabs?
Even for a 1-way slab, there is temp and shrinkage rebar in the orthogonal direction.
Was top and bottom rebar provided?
Do you have records of what got placed vs what was designed etc?
If YOU can define what is the problem, WE can all be of more assistance.
RE: slab
RE: slab
for now I didn't see any sign of cracking. We have provided proper curing procedure..but I don't know in the next few weeks or month , years..i think the crack will occur eventually due to wrong reinforcement
RE: slab
RE: slab
RE: slab
Anyway, what SPACING of M10 grade 40 (ksi I presume, although you are mixing SI and Imperial units) in both directions, T & B?
RE: slab
RE: slab
RE: slab
Top and bottom rebar continuous?
Spans are pretty damn small - 3.5m with continuity on at least 2 adjacent edges.
Slab thickness?
Is this project in the Philippines? The adopted framing and spans remind me of framing systems I used to see from PI back a decade or so ago.
RE: slab
RE: slab
I think you are right - as-built MAIN rebar yet to be provided.
Confused!
RE: slab
RE: slab
RE: slab
Are the beams 150mm or 200mm wide?
Using 275 MPa steel, I think the reo provided is slightly less than min. reo? (According to the AUS standard - 390mm2 < 480mm2)
RE: slab
RE: slab
We do MIN 100mm thick slabs for slab-on-grade (ground) with top reinf only.
20mm MIN top and btm cover, 4 x M10mm ∅ for rebar, so you have maybe 20mm clear between top layers and bottom layers.
Damn, I struggle with 150mm slab suspended thickness.
Is your code-specified min. reinforcement satisfied?
Is min. slab thickness satisfied for fire transmission/insulation between floor?
Deflections?
Floor finishes - mortar bed and ceramic tile?
Concrete block wall supported by these slab - brittle finishes!
RE: slab
RE: slab
cegrace1485, you are obviously not a structural engineer. This site is for exchange of information and advice between practicing engineers.
RE: slab
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: slab
That's not what I said. I was talking about inadequate reinforcement in one direction, whether top or bottom. Based on the section he attached, he does have top bars, at least on the drawings. But from his various descriptions, who would really know?