any concrete experts here?

The #1 community for Gun Owners in Indiana

Member Benefits:

  • Fewer Ads!
  • Discuss all aspects of firearm ownership
  • Discuss anti-gun legislation
  • Buy, sell, and trade in the classified section
  • Chat with Local gun shops, ranges, trainers & other businesses
  • Discover free outdoor shooting areas
  • View up to date on firearm-related events
  • Share photos & video with other members
  • ...and so much more!
  • ws6guy

    Expert
    Rating - 100%
    1   0   0
    Feb 10, 2010
    773
    43
    westside
    If I have a slab poured 7" thick with 4000PSI concrete with #5 aggregate on a minimum 6" compacted #53 stone base. Will this be sufficient enough hold a piece of machinery that weighs about 30,000 lbs. The equipment is a beam press and the estimated dynamic load is double the machine weight. The press has 4 feet that are 1 foot square. The soil below is listed as bearing capacity of 3,000PSF.
     
    Last edited:

    jagee

    Grandmaster
    Rating - 100%
    24   0   0
    Jan 19, 2013
    44,412
    113
    New Palestine
    Ok, this is more of a question for an engineer. But here is my $0.02...

    The concrete slab will do little to nothing to support your machine. The weight will transfer down to the footing- in this case it sounds like there isn't one. The sub grade (3000psf) may or may not support one of the feet for the base of the unit. 30,000lbs divided by (4) feet is 7,500lbs per foot (base leg).

    The concrete slab will help disperse the load out over a wider area, but you will still have point loading on the slab where the feet sit. This may cause excessive cracking in your slab around the legs. Cracking will happen, it's what concrete does, but excessive cracking will cause problems down the road.

    So, in short, to answer your question, "maybe". Lol
     

    ws6guy

    Expert
    Rating - 100%
    1   0   0
    Feb 10, 2010
    773
    43
    westside
    Great! To be honest we already at the point of no return as the press is set in place as of today. The manufacture said most of their customers only have a 4"-6" slab so we thought we were good to go. However moving the press into location today we cracked part of the slab. However the forklift caring the slab weight 60,000 lbs which means we were around 90,000. Hind sight is 20/20 that maybe we should've contacted an engineer.
     

    Backpacker

    Expert
    Rating - 100%
    27   0   0
    Apr 5, 2008
    932
    43
    Greenwood
    I'm not an engineer, but several years ago I was involved in the design and construction of precision machine foundations. The machinery manufacturer supplied design and engineering criteria that we in turn based the foundation design on.

    I see you posted just ahead of me. Good luck
     

    JRR85

    Marksman
    Rating - 100%
    4   0   0
    Oct 20, 2010
    166
    28
    NWI
    You need a footing around the perimeter and unless it was wasn’t listed you need rebar. Also, will the press cause any vibration during normal operation? That is something that needs to be considered as well.
     

    ws6guy

    Expert
    Rating - 100%
    1   0   0
    Feb 10, 2010
    773
    43
    westside
    nope no footings. The manufacture was very nonchalant when asked about concrete specifications saying they've not had any issues at customer sites. Starting to sound like we were mislead by the manufacture and we did not do our part on due diligence. I did just now talk to concrete tester at IMI and he said that the concrete should be plenty strong but it's going to depend on the base. hmmm, guess we'll probably run it and see what happens.
     

    jagee

    Grandmaster
    Rating - 100%
    24   0   0
    Jan 19, 2013
    44,412
    113
    New Palestine
    nope no footings. The manufacture was very nonchalant when asked about concrete specifications saying they've not had any issues at customer sites. Starting to sound like we were mislead by the manufacture and we did not do our part on due diligence. I did just now talk to concrete tester at IMI and he said that the concrete should be plenty strong but it's going to depend on the base. hmmm, guess we'll probably run it and see what happens.

    Know the guy from imi's name? I probably know him.

    Where is this place located? I could probably figure out who it was by region.
     

    indykid

    Grandmaster
    Rating - 100%
    4   0   0
    Jan 27, 2008
    11,859
    113
    Westfield
    Guessing the slab is already dry? Most people don't know and the people who pour the concrete don't tell you how important it is to keep the concrete damp to wet during the curing process. Concrete cures from the inside out and keeping the exterior wet allows for a longer cure giving harder surfaces.
     

    WebSnyper

    Maximum Effort
    Rating - 100%
    56   0   0
    Jul 3, 2010
    15,418
    113
    127.0.0.1
    If I have a slab poured 7" thick with 4000PSI concrete with #5 aggregate on a minimum 6" compacted #53 stone base. Will this be sufficient enough hold a piece of machinery that weighs about 30,000 lbs. The equipment is a beam press and the estimated dynamic load is double the machine weight. The press has 4 feet that are 1 foot square. The soil below is listed as bearing capacity of 3,000PSF.

    I was told there would be no math on INGO unless I got into long range shooting...
     

    nascarfantoo

    Master
    Rating - 100%
    9   0   0
    Oct 29, 2012
    3,168
    48
    Western IN
    Personally I would be more concerned with the dynamic load than the static. Dynamic loads can be much more damaging than static.

    Was there any rebar, or at least wire mesh, in the concrete?
     

    jagee

    Grandmaster
    Rating - 100%
    24   0   0
    Jan 19, 2013
    44,412
    113
    New Palestine
    Personally I would be more concerned with the dynamic load than the static. Dynamic loads can be much more damaging than static.

    Was there any rebar, or at least wire mesh, in the concrete?

    If I were to guess, it has mesh in it but installed improperly and in laying on the stone rather than in the middle of the slab. Essentially doing nothing.
     

    ws6guy

    Expert
    Rating - 100%
    1   0   0
    Feb 10, 2010
    773
    43
    westside
    since I know squat about concrete, please explain what 4000 psi concrete means. if the PSI is what the concrete can hold then wouldn't 1 sqft(144sqin) be able to hold 576000 lbs? This does't seem right to me. I guess the base would have to be perfectly capable of handling this load.

    I've seen a couple other manufacturing plants in my industry using similar size press and didn't notice any difference in the flooring around the machine. However these plants were older and would have been difficult notice. Our old press is roughly half the size of the new one and there has been zero cracking in the floor around it
     
    Last edited:
    Top Bottom