www.pedestrians... Demolition of the east wing of an office building on Nicholson Lane in North Bethesda, Maryland. It contained laboratories used for medical research. Produced by John Z Wetmore, producer of "Perils For Pedestrians".
I'm struck by how thin concrete slabs are in many of these vids. This lab facility must have been housing some heavy equipment and that slab is inadequate in terms of thickness and reinforcement (rebar looks thin as wire). It appears many of these buildings were built "on the cheap", which is perhaps why they're now being demolished? Also, the wrong machine is being used to pick and separate rebar from masonry. The concrete crumbles at the slightest touch anyway, so concentrate on breaking it up!
It will have been designed to code and laboratory loading can be quite low... 3.5 kN/m² only double domestic loading. In composite construction the bottom sheeting acts as main reinforcement and the top reinforcement is for crack control only ... basically light weight mesh like 6 or 8mm bars. The critical condition is usually the wet concrete condition during construction where it needs propping. Once cured, it is surprisingly strong for its thickness. I agree about the machine. It was too small for the height of the building and they were trying to do everything with it!
