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How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

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Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#81

Post by dizhn »

aiauthoritydev wrote: post #24

The whole promise of engineering is not to build a bridge that stands but to build a bridge that barely stands. It is not a good idea to build a bridge that last 500 years. You likely destroyed valuable resources to build one. Build a bridge that lasts 100 years and save those resources. In 100 years the technology to build bridges improves so much that it is lot easier to build a new one. At least in most countries…

Aren't structures like bridges tested to at least 1.5x design parameters? In our field it's usually 2x (pressure and lifting lug strength).

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#82

Post by rkangel »

PunchyHamster wrote: post #79
rkangel wrote: post #73

Earlier quoted context omitted.

A broader view of this point would be "the economic structures in some countries do not allow for investments with a long payback".

Or simpler: people don't exactly want a house layout that was popular 100 years ago. And definitely not the level of insulation it provided. Nor the fact putting any new wiring and piping thru concrete is PITA Tastes change and so do other requirements. but , if we actually built for longevity in use, we could build a very durable shell of a house and then use more perishable but easier to modify methods for inside.…

There are some downsides, but most people on the UK would prefer houses that were 100+ years old. In the village I live in the houses immediately around me are "only" 50 years old. Most of the ones on the main street are well over 100 years old.

Housing tastes don't really change that much. Yes over the years we've had to fit things like double glazing and better insulation but that's a whole lot cheaper (and better for the environment) than building a whole new building.

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#83

Post by graemep »

cm2187 wrote: post #78

I am glad the pantheon still stands. But the real question is are there really any modern structure that will be worth preserving for 2000 years. Architects have long abandoned aiming for beauty to aim for originality. Originality doesn’t last. Humans in 2000 years will only wonder why on earth our society could manufacture atom level micro ships but couldn’t come with a single structure worth preserving.

There are some structures worth preserving. Sagrada Família is one. Places of worship and private homes (at least those individually architect designed vs standard designs) tend to be a lot nicer than office blocks and other commercial places.

I do think a lot of new building hideous. Looking at St Paul's in London from the west so you see the hideous backdrop to its east is depressing.

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#84

Post by hkt »

croes wrote: post #32
aiauthoritydev wrote: post #24

The whole promise of engineering is not to build a bridge that stands but to build a bridge that barely stands. It is not a good idea to build a bridge that last 500 years. You likely destroyed valuable resources to build one. Build a bridge that lasts 100 years and save those resources. In 100 years the technology to build bridges improves so much that it is lot easier to build a new one. At least in most countries…

Sometimes knowledge gets lost and newer doesn’t automatically mean better

Case in point, Roman concrete

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#85

Post by fhub »

cm2187 wrote: post #78

I am glad the pantheon still stands. But the real question is are there really any modern structure that will be worth preserving for 2000 years. Architects have long abandoned aiming for beauty to aim for originality. Originality doesn’t last. Humans in 2000 years will only wonder why on earth our society could manufacture atom level micro ships but couldn’t come with a single structure worth preserving.

Sydney Opera house comes to mind as something that might still be curious to people in 1000 years.

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#86

Post by middayc »

Very interestin discussion below/above. I just want to say that building with hempcrete, which relies on lime and NHL (natural hydraulic lime) or Baumit Trassitplus whic is some version of roman "cement" relies on may of these principles and is a "modern building technique". It's also much more carbon neutral than many other methods, can produce good thermal dynamics and "breathable" walls. And is DIY friendly.

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#87

Post by ChrisRR »

cm2187 wrote: post #78

I am glad the pantheon still stands. But the real question is are there really any modern structure that will be worth preserving for 2000 years. Architects have long abandoned aiming for beauty to aim for originality. Originality doesn’t last. Humans in 2000 years will only wonder why on earth our society could manufacture atom level micro ships but couldn’t come with a single structure worth preserving.

What makes you think buildings aren't going to change within the next 2000 years? Hell just look at all of the Tudor buildings dotted around. They probably didn't think they were anything special 600 years ago

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#88

Post by benj111 »

skybrian wrote: post #2

Modern concrete has steel rebar, which is very useful, but eventually corrodes. Stainless steel rebar could be used if longevity mattered, but usually it doesn’t because the building will likely become functionally obsolete and need replacing before then.

Define functionally obsolete.

Ultimately most tall structures as a reinforced concrete skeleton with glass hung on the sides.

It seems to me that as you're going to replace it with another basically identical concrete skeleton it makes sense to have that skeleton last as long as possible. And then refit that skeleton.

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#89

Post by cucumber3732842 »

ErroneousBosh wrote: post #56
Animats wrote: post #54

Earlier quoted context omitted.

Stainless steel rebar is a thing. It's expensive, but structures built with it last much longer. Washington State now has a policy that bridges over salt water will be built with stainless steel rebar. Stainless steel costs much more, but total project cost goes up less than 10%. Epoxy coated rebar looked promising for a while, but it's on the way out. Water gets in at cuts and joints. So all field joints have to hav…

> Stainless steel costs much more, but total project cost goes up less than 10%. I think people are often surprised how little materials cost affects the total cost of a job. I'm having this argument at work, where I want some more expensive cabling installed in a bunch of offices across Scotland so it doesn't need to be done again in another ten year's time, but "that stuff is so expensive, do we really need it?" is…

>I think people are often surprised how little materials cost affects the total cost of a job.

Because people don't understand how much compliance and box checking and check the guy who checked the last guy's work there is in a "you need government permission for this and not the easy permission they give a homeowner deck project" sized construction project.

Re: How Has Roman Concrete Lasted for Millennia? 1,900-Year-Old Latrine Offers Clues

#90

Post by [deleted] »

cm2187 wrote: post #78

I am glad the pantheon still stands. But the real question is are there really any modern structure that will be worth preserving for 2000 years. Architects have long abandoned aiming for beauty to aim for originality. Originality doesn’t last. Humans in 2000 years will only wonder why on earth our society could manufacture atom level micro ships but couldn’t come with a single structure worth preserving.

[deleted]
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