71–80 of 299 posts
on the other end of the spectrum, did you know concrete can be used to demolish concrete? dexpan is a special demolition concrete mix that, when poured into holes, expands at 18kpsi. it gets used when jackhammers and explosives cant be used, for example, in refineries and explosive atmospheres.
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I live in Montreal; many of the concrete structures in my city are crumbling and decaying due to the constant freeze/thaw temperature cycling that they're exposed to. I wonder if the self-healing property of this new advanced concrete would help to avoid some of the cracking & flaking we're seeing in constructions from the 60s & 70s.
I live in Montreal too, and while all what you say is true ... the same is not true for the xUSSR cold cities I lived before immigration. So quality makes difference. Also planing and designing for less maintenance. Concrete structures from the same era across xUSSR are in way better shape.
To think that the USSR had better infrastructure (less corruption) than modern day corrupt places like Montreal is a brutal shock.
on the other end of the spectrum, did you know concrete can be used to demolish concrete? dexpan is a special demolition concrete mix that, when poured into holes, expands at 18kpsi. it gets used when jackhammers and explosives cant be used, for example, in refineries and explosive atmospheres.
Presumably dexpan has lower tensile strength so it can be disposed of easily? Or is the piece excavated and hauled away intact?
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A fun exercise is to calcualte the cost of some road in a neighboorhood, and compare that to the total collected property tax of all the homes along that road.
Then multiple that by 20 (the lifetime of the road surface) and factor in that the resurfacing is significantly cheaper than the initial build and you quickly find roads are easily subsidized by property taxes.
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Then multiple that by 20 (the lifetime of the road surface) and factor in that the resurfacing is significantly cheaper than the initial build and you quickly find roads are easily subsidized by property taxes.
Even in rural areas? Even if we add in the cost of maintaining infrastructure that runs under the road surface (water, sewer, and gas)?
I live at the end of a deadend road that is 0.9 miles off another very rural road.
The road is chip sealed, which according to google in 2022 is $25,000 to $42,000 per mile.
There are 7 parcels that collect $6396 per year in property taxes.
At the low end of the chip seal price, it would take 3.53 years to pay it off and 5.9 years at the high end.
This assumes that no sales or gas taxes are used to fund any of the road construction, which isn't true.
Earlier quoted context omitted.
I live in Montreal; many of the concrete structures in my city are crumbling and decaying due to the constant freeze/thaw temperature cycling that they're exposed to. I wonder if the self-healing property of this new advanced concrete would help to avoid some of the cracking & flaking we're seeing in constructions from the 60s & 70s.
Only if you take out the rebar. Concrete is porous, water penetrates to the rebar inside, the rebar rusts and expands, cracking the concrete. But if you remove the rebar, you remove much of the tensile strength of the structure, which means you need to use way more concrete to compensate (via the sheer compressive force of its own weight).
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for slow neighborhood roads I see no reason why brick isn't used more often. my hometown had brick roads everywhere and once every 3-5 years a few bricks would get replaced here and there. in the 1990s I'd look around and see a lot of the bricks on those roads that were made in the 1930s, and there were probably older bricks to be found if I'd looked harder. the rough ride kept speeding down a lot more than the polic…
It's not the plowing that gets bricks in winter, or not plowing exclusively, it's the freeze-thaw cycling that kills anything with joints. Every grout joint / polymeric sand joint is an opportunity for moisture intrusion and in any climate zone that gets cold enough to freeze, those joints are going to degrade incredibly quickly. Bricks may make sense in the South, but definitely not in most of the US.
Earlier quoted context omitted.
Then multiple that by 20 (the lifetime of the road surface) and factor in that the resurfacing is significantly cheaper than the initial build and you quickly find roads are easily subsidized by property taxes.
Even in rural areas? Even if we add in the cost of maintaining infrastructure that runs under the road surface (water, sewer, and gas)?
Over their lifetime, easily. The pipes for those will last 100 years, easily. The maintenance of them are paid for by the delivery costs you pay in your bill.
As for rural I think there's 2 distinctions. 1 is we need rural communities because they produce our food and other things. Secondly, rural areas are between 2 or more populated areas. We need to connect populated areas so by necessity there are roads. Rural communities are built off of those.
The other distinction where you may be closer is exuburban communities built into rural areas. These may or may not be fully covered. Not initially anyways, but you'd assume the property taxes would cover in time.