5 ms·

> reinforced concrete only has a lifespan of about 100 years. Currently, less than 1% of rebar is made from stainless steel: https://www.youtube.com/watch?v=zn

• scythe 3y ago
  Stainless steel contains a necessary 12% (often more, usually 18%) chromium, which is relatively scarce from a building materials perspective. Already 85% of available chromium is used for stainless steel; many other metals are primarily supplied as byproducts of chromium extraction because of the extensive efforts [1, 2] made to locate and exploit deposits. In fact, total rebar production is roughly the same scale (if not larger) as total stainless steel production, meaning that practically the entire world supply of stainless steel would have to be diverted to rebar in order to use it for this. In general only the 12 or so most common elements can be used for construction. Copper is the rarest material used in major applications, but this is relatively less total mass consumed than rebar. 1: https://en.wikipedia.org/wiki/Bushveld_Igneous_Complex#Mining https://en.wikipedia.org/wiki/Bushveld_Igneous_Complex#Minin... (50% of world supply) 2: https://en.wikipedia.org/wiki/Ring_of_Fire_(Northern_Ontario) https://en.wikipedia.org/wiki/Ring_of_Fire_(Northern_Ontario...
  • p1mrx 3y ago
    > Copper is the rarest material used in major applications, but this is relatively less total mass consumed than rebar. At 43:51 in the video, he claims that an outer layer of stainless steel rebar is sufficient to protect the interior, so the goal is not 100% stainless. https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth... says chromium is slightly more abundant than copper.
• quickthrowman 3y ago
  It’s probably close to 10x the price. I occasionally buy stainless steel strut and a 10’ stick of 12ga 1-5/8” deep SS 316 strut is around $250. The same strut made of galvanized steel is around $40.