Comments: - - I have a degree in materials engineering, and have worked in concrete prestressed bridge beam construction. The comments below are correct. The steam aids in curing the concrete. The base plates are used to tension the steel rebar core. These both help speed the process and make for a much stronger end product. Steel is very strong in tension and concrete is very strong in compression. When you combine the two strengths of each you get an even stronger more flexible end result.

The first object they were securing to the steel cage was the baseplate. This is the "top" of the piling, as the piling will be sunk into the ground. The steel building will be bolted and possibly also welded to these baseplates.

The steaming helps the concrete cure faster. It hardens better, faster this way.

Thanks for uploading this video; nobody will ever see those pilings when they are in use but it is nice to know what the roots of your high-rise look like.

I have a degree in materials engineering, and have worked in concrete prestressed bridge beam construction. The comments below are correct. The steam aids in curing the concrete. The base plates are used to tension the steel rebar core. These both help speed the process and make for a much stronger end product. Steel is very strong in tension and concrete is very strong in compression. When you combine the two strengths of each you get an even stronger more flexible end result.