Steel beam encased in concrete.

[jvolk]

There is an old existing building with what I believe are steel shapes encased in concrete. What test is the best way, to determine the steel shape inside of the concrete hopefully with out demolishing the beam?

 

[Ron]

The most accurate would be radiography; however, this will be expensive and the thickness of the concrete will limit the device to an active cobalt radiation source if the thickness is greater than about 12 inches. There are only a few labs in the country that maintain cobalt radiation sources.

You could try ground penetrating radar using an antenna that has a frequency consistent with concrete surveying (about 900 mhz).

 

[lexim]

Hi jvolk,

From an investigation point of view i.e supporting either side of the beam where the inspection is to be carried out.

An elemental width of the concrete beam may be chipped off to the top of the bottom flange and also at the side of the concrete beam(at a position). The width and thickness of the top flange can be determined by chipping the cover off the concrete near the top of concrete beam to expose the steel section. Remember to use concrete patch to close up exposed section on completion of inspection.

On completion of determining the steel section dimensional properties, futher test or emperical analysis can be used to deduce the steel grade (this should bbe taken as the lowest steel grade- it is good to be conservative for design).

Lexim

 

[csd72]

agree with lexim, it is not that much trouble to expose the bottom flange of the beam and then the actual beam size can usually be determined from this.