let me guess, the didn’t fill it with iron that would corrode and expand and blow out the concrete? or the fact that it has an excess of fired lime that re-seals cracks?
Yep, it’s the the lime. And:
“ The team is now working on commercializing their concrete as a more environmentally friendly alternative to current concretes.”
Quick lime as a ‘concrete’ is nothing new, or newly rediscovered though… The story seems to come up every few years, and anyone that has used a fluidised lime boiler knows how good quick lime is at forming concrete.
that’d be great, a lot of buildings are torn down just because the concrete cracks.
i’d be interested in seeing how using better concrete impacts overall costs and of course emissions. because the building ends up standing for a lot longer, the temperature isolation becomes very sub-par over time. that would increase total energy consumption compared to buildings that are frequently rebuilt.
Epoxy covered rebar exists as does one made from stainless steel. It’s just quite pricey so it’s rarely used unless absolutely necessary. Rust is generally not an issue as long as the rebar is deep inside the concrete. When it’s close to the surface and gets exposed to elements is when the problems start.
Isn’t titanium too rigid for this application though? I’ve worked with both for a mechanical application, and titanium has no flex, so stresses get passed in to other components.
I don’t know, I’m no civil engineer. Any civvies wanna fill us in?
I’d say all the Civil engineers who continue to spec steel do it for well-established reasons.
Steel is just so hard to beat in so many applications. Even for the average road bicycle, surprisingly. Because steel can tolerate more flex than things like aluminum/titanium/carbon fiber. So other materials require different designs. In the end, the average street bike in steel or aluminum can often weigh the same, depending on the design choices (not specialized bikes, where different compromises are made).
Like so many things, when used as designed in concrete, steel is just fine, and I assume meets the cost, availability, industry knowledge, etc, goals.
Makes me think of “don’t remove a fence until you know why it’s there”. Every year upcoming engineers do tests during their education. If a different material was a better choice, I’m sure a research arm of a university would present it.
let me guess, the didn’t fill it with iron that would corrode and expand and blow out the concrete? or the fact that it has an excess of fired lime that re-seals cracks?
Yep, it’s the the lime. And: “ The team is now working on commercializing their concrete as a more environmentally friendly alternative to current concretes.”
Quick lime as a ‘concrete’ is nothing new, or newly rediscovered though… The story seems to come up every few years, and anyone that has used a fluidised lime boiler knows how good quick lime is at forming concrete.
And, coincidentally, every time the story comes up there’s a company ready to sell you the magic roman concrete.
Yeah, I was thinking it’s like the “Voyager Has Left the Solar System” story - we’ve heard that several times over the years, and probably will again.
To be fair, we keep expanding what we class as the solar system. Poor old voyager keeps getting the goalposts moved!
The year is 76,014. Voyager still hasn’t left the solar system. Also, the solar system now contains Proxima Centauri.
What is that, like 12 people now?
that’d be great, a lot of buildings are torn down just because the concrete cracks.
i’d be interested in seeing how using better concrete impacts overall costs and of course emissions. because the building ends up standing for a lot longer, the temperature isolation becomes very sub-par over time. that would increase total energy consumption compared to buildings that are frequently rebuilt.
but very promising.
the iron is a great way to increase tensile strength, but decreases lifespan, rust free metals would also be much nore expensive.
Epoxy covered rebar exists as does one made from stainless steel. It’s just quite pricey so it’s rarely used unless absolutely necessary. Rust is generally not an issue as long as the rebar is deep inside the concrete. When it’s close to the surface and gets exposed to elements is when the problems start.
Wdym? Just replace the iron rebar with gold
Gold is no where near strong enough.
Titanium would work just as well, and last quite a bit longer.
Isn’t titanium too rigid for this application though? I’ve worked with both for a mechanical application, and titanium has no flex, so stresses get passed in to other components.
I don’t know, I’m no civil engineer. Any civvies wanna fill us in?
That could be. Maybe some alloy? Not sure
Aluminum then?
I’d say all the Civil engineers who continue to spec steel do it for well-established reasons.
Steel is just so hard to beat in so many applications. Even for the average road bicycle, surprisingly. Because steel can tolerate more flex than things like aluminum/titanium/carbon fiber. So other materials require different designs. In the end, the average street bike in steel or aluminum can often weigh the same, depending on the design choices (not specialized bikes, where different compromises are made).
Like so many things, when used as designed in concrete, steel is just fine, and I assume meets the cost, availability, industry knowledge, etc, goals.
Makes me think of “don’t remove a fence until you know why it’s there”. Every year upcoming engineers do tests during their education. If a different material was a better choice, I’m sure a research arm of a university would present it.