Concrete foundations
Concrete foundations
(OP)
What is the formula for calculating the thickness of a concrete foundation from a predetermined Soil Bearing load? With a Soil Bearing load of 2,000psi, what thickness would my foundation need to be, in order to have a foundation strength of 3,000 psi. The purpose is to find out how many yards of concrete will be required, For cost estimating purposes.
Regards
Mhall
Regards
Mhall





RE: Concrete foundations
Question is a bit confusing........but, generally for an allowable bearing pressure, the thickness of concrete required depends on the loads to be supported, both vertical, horizontal and, if applicable, moment......other loading conditions such as seismic, wind or vibration need to be considered as well.......
The footing should generally be reinforced concrete, designed to resist the forces.......
Of course the allowable bearing pressure should be determined by a qualified engineer using soil boring data or at least some information about the soil......
If you can provide more specific information, it will be easier to provide a better answer........
RE: Concrete foundations
according to soil situation, weak or strong, you should thing fiber reinforced concrete.
if ground not hard enough use 50 mm from bottom wiremesh and 1,8kg/m3 fibermesh.
if ground good enough use 1,8kg/m3 fibermesh alone.
if ground perfect use 0.9kg/m3 fibermesh.
the main idea : ----------U---------- surface
joint 1/3 20
wiremesh 50mm --0--0--0--0--0-- cm
///\\\///\\\///\\\///\\ground
RE: Concrete foundations
Address: PCA, 5420 Old Orchard Road, Skokie, Illinois 60077-1083
It contains some charts that you can read off the slab thickness based on the design loads of the column. I think that could be very helpful for your cost estimation.
RE: Concrete foundations
Respect the second question, excavation in general, you can consult for example
Moving the Earth 4th Ed.
Nichols and Day
Mc Graw Hill
Standard Handbook of Heavy Construction 3d ed.
O' Brienm Havers, Stubbs Jr.
Mc Graw Hill
Respect concrete, in developed countries it is unlikely that for structural purposes reinforced concretes of less than specified compressive strength 25 MPa be now used, since cement contents -correlative to strength- is very significant in the protection against corrosion. However for poor cement content and mass concrete boulder foundations, or preparation layers, lower strength concretes are used, maybe up to a minimum of 10 to 7 MPa, but more typically in the 10 to 15 MPa range.
RE: Concrete foundations