5 ms·
That's probably true, steel rebar has the issue of rusting and cracking the concrete. But the advantage rebar gives you is a gradual failure mode, where the st
by gitgud 7y ago
That's probably true, steel rebar has the issue of rusting and cracking the concrete.
But the advantage rebar gives you is a gradual failure mode, where the steel holds the block together while the concrete cracks.
Without rebar, the failure of concrete is usually catastrophic (instant).
- darkpuma 7y agoThe alternative to rebar is making sure your structure is under compression with negligible tension.
- njarboe 7y agoIf your building site never has earthquakes, that can work well. Otherwise an earthquake might put some part of the structure under tension and cause it to fail.
- darkpuma 7y agoThe solution to that is to build it bigger with a wider footprint. Obviously this is an expensive way to build, but if you engineer it right (and throw enough concrete at it) you can create structures with nearly arbitrary shake resistance. (Think of how hard you'd have to shake the Great Pyramid of Giza to make it collapse. That's not concrete obviously, but it too is under compression almost entirely, except for the corbel and lintel ceilings. The proper arches used in Roman concrete construction show that with the right engineering you can push unreinforced concrete pretty damn far. The Pantheon is probably the most impressive example of it. Compare how well it's withstood earthquakes with the Colosseum.)
- primis 7y agoThe Pyramids actually did experience earthquakes, knocked off the limestone facades that eventually ended up being moved and used to build mosques in the area. https://www.thevintagenews.com/2016/09/06/the-great-pyramid-of-giza-was-once-covered-in-highly-polished-white-limestone-before-it-was-removed-to-build-mosques-and-fortresses/ https://www.thevintagenews.com/2016/09/06/the-great-pyramid-...