I don't have a lot of concrete experience, just a few foundation and slab pours. I have been told rebar isn't needed anymore because of the fiber added in the mix. Is this true for normal slabs and foundations, generally when is it needed or not needed?
It actually has quite a bit, but the dam structure itself did not require much because it doesn't have any tensile forces going on, since it is a horizontal arch.
What you gotta remember is that concrete is strong in compression(which is the type of load Hoover Dam puts on it) but weak in tension. In other words, if you have a long piece of concrete supported on each end, it is real easy to break by applying a load to the center. Put a rebar in the bottom of it: much stronger.
Rebar is necessary when it is necessary, and not when it isn't. Concrete is an engineered material, which means that the requirements need to be factored into design of the mix and the reinforcing of the structure.
Rebar is not required for a sidewalk, but may be for a cantilevered counter top of the same size and shape. When in doubt, do not throw more steel into the design, throw in more knowledge.
Contractor Talk - Professional Construction and Remodeling Forum
A forum community dedicated to professional construction and remodeling contractors. Come join the discussion about the industry, trades, safety, projects, finishing, tools, machinery, styles, scales, reviews, accessories, classifieds, and more!