It will come as no surprise to any engineer looking at that photo to hear that it was taken in a multi-story garage. What we’re seeing is the logical conclusion of water seeping through concrete (concrete is not waterproof, really) carrying road salt and causing accelerated rusting of the rebar in the concrete beams. Those …
When I mentioned some of the odd columns designs that used to be allowed, I said that I had seen examples of all of them. As it happens, I saw another example yesterday and it seemed worth discussing. The badly-framed picture above shows a probe at a round concrete column in a circa 1910 industrial …
A couple of years ago I wrote a series of blog posts on incompatibility, how trying to achieve one goal in design makes another goal difficult or impossible to reach. (I suggest using the search box on the right, as those posts were not on consecutive days.) The picture above, from a factory being converted …
Late last year, I wrote a long post on survival bias, and mentioning that topic yesterday made me realize I missed one aspect of it. When I discussed the topic before, I talked about how we don’t see a random cross-section of buildings from the past: we tend to see the better-constructed buildings because the …
Every structural material has its strengths and its weaknesses, and each has a feel and a look. But it can get confused, like the wood-grain concrete in the photo above. Old concrete was board-formed, cast in wood forms typically made of 1 by 6 planks. The easy way to identify board-formed concrete is to look …
