load-rating an existing slab-on-ground

huangyhg

load-rating an existing slab-on-ground
an owner would like to confirm the load-carrying capacity of an existing slab-on-ground at a one-story warehouse built in the 1940's.  a typical bay within the warehouse is 50'x35'.  unfortunately, there are no existing drawings available and the warehouse owner wants to avoid any destructive investigations (such as coring, slab removal, sub-grade soil testing, etc.).  realizing these limitations makes our job very difficult, does anyone know of a technique to reasonably test an existing slab-on-ground?
use a falling weight deflectometer.  it will give you the load capacity of the floor slab and give you some stiffnes information about the subgrade.
there are non-destructive methods of determining the size and location of reinforcement, but that would not test the subgrade, so might not be much help.
ba
any history of what has load been put onto the slab, and any damage or otherwise associated with that load?
mike mccann
mmc engineering
the falling weight deflectometer, as ron noted, is one very good ndt means.  you might want to do a core to determine strength of concrete and other information.  take a soil sample at the same location to get an idea of the type of construction and soil type and possible subgrade modulus.
taking two cores and soil samples may give better information <g>.
dik