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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

#171

Post by folbec »

ajwin wrote: post #99

A lot of the reason why concrete structures have failed so quickly is that the material was still fairly new when most of the structures failing now were created. There’s nothing that says that well designed and constructed modern high performance polymer modified concretes will have the same problems. They also have additives like zypex paste that make it more waterproof and self healing. They also have permeable fo…

"A lot of the reason why concrete structures have failed so quickly is that the material was still fairly new when most of the structures failing now were created."

Or the designer can get too creative :

https://edition.cnn.com/2025/05/15/style/432-park-avenue-sky...

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

#172

Post by mixmastamyk »

IAmBroom wrote: post #146
throw0101d wrote: post #139

Earlier quoted context omitted.

> Stainless steel rebar is a thing. It's expensive […] That's an understatement. Fiberglass (GFRP) tops out at roughly US$ 2.50/foot, while SS can get up to $9: * https://www.wellcoindustries.com/the-cost-of-rebar-and-the-c... The low-end of plain steel rebar is $0.40.

As the GP noted, it's still only a small bump in overall cost.

Also lower TCO, total cost of ownership.

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

#173

Post by bityard »

IAmBroom wrote: post #144
carlmr wrote: post #94

Earlier quoted context omitted.

>Fun fact! Lime putty is anti-mold even in humid conditions because upon exposure to moisture, CaOH2 + H20 becomes too basic for mold to grow on. Can we use this instead of grout in the bathroom somehow?

Pure silicone caulk is mold-proof, even in the white variation. The various "improvements" in many caulks allow mold to get a foothold.

After decades of owning multiple bathrooms and only using products advertised as 100% silicon caulk, I can assure you that it is not mold-proof.

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

#174

Post by Brendinooo »

rkangel wrote: post #82
PunchyHamster wrote: post #79

Earlier quoted context omitted.

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…

Having been around enough houses (in the US) to have a balanced opinion - I personally prefer older houses but

- older houses tend to be a lot more inefficient in their use of square footage

- the rooms inside tend to be a lot less open, and one man's "fun/quirky layout" is another man's "why do I have to go down a step then immediately go up a step to cross a hallway"

- and, I begrudgingly admit (as I don't like how they wreck house aesthetics) people really like big, attached garages

My overall suspicion is that when a lot of people say they like old houses, what they really mean is that they like buildings that look beautiful on the outside and, to a lesser extent, have a sense of being rooted in some kind of context.

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

#175

Post by FuriouslyAdrift »

carlmr wrote: post #94
iknownothow wrote: post #74

For those not familiar, the secret ingredients are to do with the Lime Cycle [1]: 1) Quicklime/Slakedlime (Calcium Oxide, CaO) 2) Lime (Calcium Hydroxide, CaOH2) 3) Limestone (Calcium Carbonate, CaCO3) To keep it simple, typically you start with Quicklime (CaO) and after construction you end up with some mix of all three and after hundreds of years, the masonry transitions to mostly Limestone with microscopic traces…

>Fun fact! Lime putty is anti-mold even in humid conditions because upon exposure to moisture, CaOH2 + H20 becomes too basic for mold to grow on. Can we use this instead of grout in the bathroom somehow?

There is a variation of lime wash that includes a fatty oil as a sealant and has been around for 100s of years

https://en.wikipedia.org/wiki/Tadelakt

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

#178

Post by SoftTalker »

_n_b_ wrote: post #102
ErroneousBosh wrote: post #56

Earlier quoted context omitted.

> 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've worked on a few big EPC projects in a specialised industrial sector, including some in the UK. Three things drive the first digit of cost, assuming you've hired relatively competent engineers and constructors: 1. (Design) Building floorplate and architectural complexity (i.e., divergence from 'big box') 2. (Construction) Schedule adherence. Almost any one-off expense to stick to the schedule is worth it, but to…

Not permitting and regulation? We're told that is the biggest impediment to development.

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

#179

Post by SoftTalker »

PunchyHamster wrote: post #77
ErroneousBosh wrote: post #56

Earlier quoted context omitted.

> 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. It's because they frankly never did it. Nobody that had to contract something around the house is surprised by cost like that, it often costs more than price of renting equipment + you doing it yourself 3 times slower than an expert would did it, even if you're paid well. There is reason there is so many DIY channels, labo…

It's why plumbers use $25 sharkbite fittings now instead of soldering in a $2 copper fitting. But of course the sharkbite relies on a rubber O-ring and will probably leak in 10 years, the plumber will be long gone or the property probably under new ownership who don't remember.
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