Generally, full-scale load testing follows the provisions laid out in the International Building Code (IBC). The structure is shored and a tank or some other means of applying load is installed. Devices are installed to measure the deflection of the structure during testing. The structure is then gradually loaded until the specified test load is reached (often 2x the final rated load) and the final deflection is measured. The load is held for 24 hours and then released. The deflection is continually measured as the structure “rebounds” from the load for an additional 24 hours. Provided that the structure does not exceed the calculated maximum deflection and rebounds sufficiently after the load is removed, the structure will be deemed to have passed and the rated load can be determined.
Sometimes during the renovation or repurposing of an existing building, the need arises for full-scale load testing. This is most often the case when original building drawings are not available and/or the original construction is of such a configuration as to not be easily analyzed. In some cases, damage to an existing structure may have occurred from water, fire or other means and the existing capacity is in question. In other cases, a limited increase in the rated capacity of a system is requested but conservative calculations do not accurately reflect the excess capacity of that system.