Stone Concrete definition 1

[IrvStrucNewbie]

Hi all,

I am relatively new to this profession and I have a question about concrete types that I came across on an as-built set of drawings from the 1980s. The project is a steel-framed office building w/ concrete over metal deck slabs to which we are adding new equipment. Nowhere in the detail or general notes can I find the weight information (NWC or LWC) of the concrete. It either says "Hardrock" or "Stone concrete". The typical deck is "2 1/2" stone conc over 3" W-3 Deck". I couldn't find anything on the name "stone concrete" after some quick search...

Thanks for the help.

 

[Ron]

That's a crappy description of concrete even for the time period. Unless it specifically states lightweight structural concrete I would assume conventional concrete with a unit weight of 140 to 150 pcf depending on your local aggregate type. If calcareous aggregates, 140 pcf. If quartzite or other, 145-150 pcf.

 

[r13]

For weight concern, I agree with Ron, it looks like to be a 5-1/2" normal weight concrete with 3" deep metal deck. Anywhere on the drawing indicating concrete compressive strength, fc'?

 

[IrvStrucNewbie]

Thanks for the response guys. @retired13, yes there are. Typical floors have f'c of 3000 psi, nonstructural SOG is 2500 psi and the roof w/ penthouse is 4000 psi.

 

[r13]

Another interpretation, my guess, can be concrete made out from "crashed stone" for hard rock concrete, and "natural stone" for stone concrete. In the local where I came from, the quality of the latter is considered superior to the former for better bonding with cement, thus higher strength, and water tightness, can be achieved with the same mix proportion. A believe of the past.