sh00g

Planning and running my homebrew ttrpg campaign. I've sunk nearly three years into fleshing out my setting from plate tectonics to modern geopolitics!

This is one of the most commonly touted engineering myths that simply doesn't hold up to even a brief analysis. The first glaring problem is the inherent survivorship bias behind claiming Roman concrete was objectively better than modern concrete. As other users have already mentioned, modern concrete is actually very strong and exceeds the strength of Roman concrete when such strength is required, but where it really has an advantage is in its consistency.

If every concrete structure built in Rome was still standing and in good shape to this day, engineers would be salivating over the special blend and would be doing whatever they could to get their hands on it or replicate it. But we don't see that. We see the Roman concrete structures that have survived the test of time (so far), not the myriad structures that have not. Today's concrete on the contrary is deliberately consistent in chemistry, meaning even if it typically isn't designed to last hundreds of years, you can say with a great deal of confidence that it will last at least X years, and all of it will likely exhibit similar wear and strength degradation behaviors over that same duration.

There are other factors at play too:

1. Romans didn't use steel reinforcing re-bar, instead opting for massive lump sums of concrete to build structures. These massive piles are better against wear and porosity-related degradation, especially due to the self-healing properties of the Roman concrete blend due to volcanic ash helping to stop crack propagation.
2. Our modern concrete structures are much, much larger in many cases and/or are under significantly higher loads. Take roads for example—no Roman road was ever under the continued duress of having hundreds of 18 wheelers a day rumble over them.
3. Our modern concrete structures do things that would have been considered witchcraft to a Roman civil engineer. Consider the width of unsupported spans on modern concrete bridges compared to the tightly packed archways of Roman aqueducts.

None of this is to detract from Roman ingenuity, but to make the claim that Roman concrete was objectively better than what we have today is farcical.

Probably To Kill a Mockingbird and Fahrenheit 451 were my two favorites from my high school years.

This Old Tony, Abom, Tested (mostly just One Day Builds by Adam Savage), Wirtual, Isaac Arthur, CityNerd, Intelligence Squared debates, FloridaMan Diplomacy, Abom79

This is how I want to go out. A burial fit for a king indeed.

Yep a theater company in my town recently put on a play dramatizing the closing of the city's pools. Instead of integrating they filled the pools frequented by white patrons with concrete and the one frequented by black patrons with garbage. It also touched on the fact that the lack of availability for safe public swimming locations has led to needless deaths of hundreds and hundreds of black people who opted to swim in fast moving creeks and waters connected to industrial facilities. All because racists were unwilling to share a body of water with someone with a different color of skin.

Agreed with all your points. I used to love Airbnb because it was so much cheaper than staying in a hotel and would give you access to stay in areas much farther off the beaten path. But the last three times I have stayed in an Airbnb I or someone else from my party ended up on the phone for hours with them because the host blatantly lied about something in their listing or otherwise was inhospitable during the stay. Hotels are just way more consistent and when something does go wrong during your stay, you can at least count on a decent customer service experience.