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?
You do know that rebar frames are completely essential for most concrete construction right? It’s not some conspiracy to induce failure. Concrete by itself can only handle compression forces - the rebar allows it to handle tension, torsion and sheering.
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.
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.
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.
Meh. Lime mortar absorbs and releases moisture. IRC “Roman” lime concrete is much the same.
Don’t get me wrong, I’m a huge fan, but that kind of thing isn’t compatible with modern insulation. You end up with damp and mould issues in the walls.
Sure it works great in uninsulated stuff though. But people and governments want every room in a building to be insulated nowadays. The whole one warm room, the rest of the building is cold and you’d better wear a three piece suit or heavy wool jumper thing, is abhorrent to our spoiled western arses.
Also: the Romans didn’t build their buildings that high. AFAIK Lime concrete has lower tensile and compressive strength, which is an issue with high rise buildings.
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.
Gold is no where near strong enough.
Titanium would work just as well, and last quite a bit longer.
