Building concrete slab
Building concrete slab
(OP)
I have a 4 story building that is 119' long by 25' wide. The lower floor has an elevated slab. Which is more economical?
1. Design the slab as a 1 way slab in the 25' direction?
2. Add beams down the 119' direction and design as 1 way slab.
3. Do number 2 and design as 2 way slab.
1. Design the slab as a 1 way slab in the 25' direction?
2. Add beams down the 119' direction and design as 1 way slab.
3. Do number 2 and design as 2 way slab.






RE: Building concrete slab
25' single one-way span slabs will results in pretty thick slabs, that may not be economic, depending on your location and its construction practices.
Continuity via incorporating 'supports' (columns, beams etc) will assist in reducing slab thickness, at the expense of increasing forming costs. If this is a prelim design stage, I have often checked out/presented two options and do prelim costing (or give it to the contractor for pricing info, if a GC is on-board) then base the final design on the selected system.
All adding beams, columns often has impacts to M/E/P and the architect usually has some significant input too.
RE: Building concrete slab
Project in DC
RE: Building concrete slab
1) Pan joists.
2) Topped precast hollow core planks.
If you have concrete perimeter walls that would be located beneath your beams, I'd definitely be looking to eliminate the beams.
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: Building concrete slab
RE: Building concrete slab
If you can't do that, I would put 25' long beams every 10' to 15' or so and span a one-way continuous slab in the 119' direction.
RE: Building concrete slab
But PT with tendons of 25' long are very UNeconomic. You want to optimize your anchorage hardware/fabrication costs over the longest possible tendon length, and also keep installation and stressing (labor) costs to a minimum by have longer tendon lengths.
RE: Building concrete slab
RE: Building concrete slab
RE: Building concrete slab