As the title suggests. If roman concrete supposedly has the capabilities to mend tiny cracks via chemical reaction, why isn’t it used with modern reinforcements to seal the pathways to the steel beams to protect it from oxygen and elements and prevent corrosion? Are there any major downsides to hot-mixed concrete, is it not as good as the studies make it out to be, or is it simply not viable due to cost and manufacturing process/storage requirements?
Up until they had trucks to deliver concrete the process of pouring walls was completely different than what they do today. If you even tear into a concrete wall from 100 years ago what you find is concrete around all the big rocks they could throw in. It was cheaper and easier to use the concrete as a medium to hold stones than to entirely make up the wall. If you have ever mixed concrete by hand in a wheelbarrow you would understand.