TDLR; Reject modernity, Embrace Empire!
So for the non history guys wondering why this is a big deal 'we already have concrete?' Yes and it can be stronger than Roman concrete but does not have the longevity of roman concrete as look at the amount of Roman architecture still standing when left untouched by humans for thousands of years.
The cause is it's structure, roman concrete has a lot of lime deposits in it. When over time cracks form, when it rains the water reacts with these lime deposits, recrystalise and fill the cracks, essentially self healing the structure. The romans had nanomachines before they were a thing. Near seawater, their structures actually got tougher over time due to exposure to the minerals in the seawater.
So us finally understanding this means we can now create longer lasting and even stronger structures given time. Lets just hope this Roman concrete is ONLY used in ancient, renaissance or gothic architecture and not any of the shit we make nowadays!
Thought this was a fun example of how much studying history is extremely important to improving the current world.
Quite true unfortunately, at least now we know how it works, we can make structures in the style of those times or at least renaissance.
Or just fix old roman structures, how about we start with that wall in the UK between Scotland and England, both sides would probably enjoy that..
Need to build it into the hearts of the people first. Then make sure it's not for some other despot.