Precast concrete beams, circa 1920

[Hacksaw82]

Hi all, I have a building reno in Detroit, Mi. It was constructed around the early 1920s. The entire building is reinforced concrete. The floor appears to be precast "I beams". Structurally, they really act as tee beams, as the bottom steel is only located in the web, but they are shaped like an 'i'. They are about 8" deep, 12" wide, and have a topping slab on top, with tarazzo finish. They span about 16'.

We can do analysis on the geometry, and test the materials, but are interested if anyone has ever seen these things. Or has any idea about their origin.

 

[SlideRuleEra]

They were probably cast on site, by the building contractor. To my knowledge, precast concrete items like this were not manufactured (for sale) at that time.

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