The recipe for Roman concrete was recorded, but most places didn't have access to the materials and conditions necessary to produce it: https://www.sciencemag.o

The recipe for Roman concrete was recorded, but most places didn't have access to the materials and conditions necessary to produce it: https://www.sciencemag.org/news/2017/07/why-modern-mortar-crumbles-roman-concrete-lasts-millennia https://www.sciencemag.org/news/2017/07/why-modern-mortar-cr...