5 ms·

Concrete: The most destructive material on Earth

33 points by omarfarooq 5y ago

southerntofu 5y ago
TLDR > Take the floods in New Orleans after Hurricane Katrina and Houston after Harvey, which were more severe because urban and suburban streets could not soak up the rain like a floodplain, and storm drains proved woefully inadequate > Concrete is a thirsty behemoth, sucking up almost a 10th of the world’s industrial water use. This often strains supplies for drinking and irrigation, because 75% of this consumption is in drought and water-stressed regions. > It also worsens the problem of silicosis and other respiratory diseases. The dust from wind-blown stocks and mixers contributes as much as 10% of the coarse particulate matter that chokes Delhi > At this scale, even the acquisition of sand can be catastrophic – destroying so many of the world’s beaches and river courses that this form of mining is now increasingly run by organised crime gangs and associated with murderous violence. > The biodiversity crisis – which many scientists believe to be as much of a threat as climate chaos – is driven primarily by the conversion of wilderness to agriculture, industrial estates and residential blocks. > But, like the US, Japan, South Korea and every other country that “developed” before it, China is reaching the point where simply pouring concrete does more harm than good. Ghost malls, half-empty towns and white elephant stadiums are a growing sign of wasteful spending. Take the huge new airport in Luliang, which opened with barely five flights a day, or the Olympic Bird’s Nest stadium, so underused that it is now more a monument than a venue. Although the adage “build and the people will come” has often proved correct in the past, the Chinese government is worried. After the National Bureau of Statistics found 450 sq km of unsold residential floor space, the country’s president, Xi Jinping, called for the “annihilation” of excess developments. > As the Chinese landscape architect Yu Kongjian has pointed out, it also suffocates the ecosystems – fertile soil, self-cleansing streams, storm-resisting mangrove swamps, flood-preventing forests – on which human beings ultimately depend. It is a threat to what he calls “eco-security”. > Beijing’s much-vaunted Belt and Road Initiative – an overseas infrastructure investment project many times greater than the Marshall Plan – promises a splurge of roads in Kazakhstan, at least 15 dams in Africa, railways in Brazil and ports in Pakistan, Greece and Sri Lanka. To supply these and other projects, China National Building Material – the country’s biggest cement producer – has announced plans to construct 100 cement factories across 50 nations. Plus paragraphs about the aesthetics (or lack thereof) of a concrete jungle, the sentiments of people surrounded by huge walls on the shores of Japan, and the vast corruption/mafia behind the construction/concrete industry.
fomine3 5y ago
For Asia/Brazil part, is it a problem of concretes? Anyway we need alternative to concretes, but waste corrupt building may happen even without concretes.
smitty1e 5y ago
> In the time it takes you to read this sentence, the global building industry will have poured more than 19,000 bathtubs of concrete Let's see. Google says 13ft² * 19000=247000ft² And someone uses 10sec to read the sentence Surface area of earth=5.49 × 10^15 ft² 10 * 60 * 60 * 24 * 365.25 = 315576000 bathtub-sentence-years 5490000000000000/247000/31557600 704.322276yrs until the planet is covered in concrete.
- eesmith 5y ago
  Quoting https://www.cnbc.com/2021/03/05/sand-shortage-the-world-is-running-out-of-a-crucial-commodity.html https://www.cnbc.com/2021/03/05/sand-shortage-the-world-is-r... : > The UN estimates that 4.1 billion tons of cement is produced every year, driven primarily by China See also https://www.statista.com/statistics/267364/world-cement-production-by-country/ https://www.statista.com/statistics/267364/world-cement-prod... . Concrete is about 2,000 kg/m³ - https://www.engineeringtoolbox.com/concrete-properties-d_1223.html https://www.engineeringtoolbox.com/concrete-properties-d_122... 704 years * 4.1 billion metric tons/year / (2,000 kg / m / m / m) / (510,064,472 km * km ) => 2.83 mm So, 704 years to cover the planet in 3mm of concrete. The article says "In a single year, there is enough to patio over every hill, dale, nook and cranny in England". I am not able to reproduce that. Using 130,279 km2 from https://en.wikipedia.org/wiki/Geography_of_England https://en.wikipedia.org/wiki/Geography_of_England (4.1 billion metric tons) / (2,000 kg / m / m / m) / (130,279 km * km) => 1.57 cm https://duckduckgo.com/?t=ffsb&q=concrete+patio+thickness&ia=web https://duckduckgo.com/?t=ffsb&q=concrete+patio+thickness&ia... suggests 4 inches is the minimum depth for a patio, or about 10 cm. Which means it would take about 6 years to patio England. FWIW, 4.1 billion metric tons/year * 10 seconds => 1.3 kilo tons 1.3 kilo tons / density of concrete => 650 kilo Liters 650 kL / 19,000 bathtubs => 32 liters per bathtub I doubt UK bathtubs are 32 L. I'm finding numbers like around 150-200 L for a bathtub - https://duckduckgo.com/?q=volume+of+a+bathtub+in+liters&t=ffsb&ia=web https://duckduckgo.com/?q=volume+of+a+bathtub+in+liters&t=ff... .
  - smitty1e 5y ago
    How exactly we're curing all of this concrete over the ocean surface is left as an exercise for the straight-line approximation aficionado.

33 points by omarfarooq 5y ago

TLDR > Take the floods in New Orleans after Hurricane Katrina and Houston after Harvey, which were more severe because urban and suburban streets could not soak up the rain like a floodplain, and storm drains proved woefully inadequate > Concrete is a thirsty behemoth, sucking up almost a 10th of the world’s industrial water use. This often strains supplies for drinking and irrigation, because 75% of this consumption is in drought and water-stressed regions. > It also worsens the problem of silicosis and other respiratory diseases. The dust from wind-blown stocks and mixers contributes as much as 10% of the coarse particulate matter that chokes Delhi > At this scale, even the acquisition of sand can be catastrophic – destroying so many of the world’s beaches and river courses that this form of mining is now increasingly run by organised crime gangs and associated with murderous violence. > The biodiversity crisis – which many scientists believe to be as much of a threat as climate chaos – is driven primarily by the conversion of wilderness to agriculture, industrial estates and residential blocks. > But, like the US, Japan, South Korea and every other country that “developed” before it, China is reaching the point where simply pouring concrete does more harm than good. Ghost malls, half-empty towns and white elephant stadiums are a growing sign of wasteful spending. Take the huge new airport in Luliang, which opened with barely five flights a day, or the Olympic Bird’s Nest stadium, so underused that it is now more a monument than a venue. Although the adage “build and the people will come” has often proved correct in the past, the Chinese government is worried. After the National Bureau of Statistics found 450 sq km of unsold residential floor space, the country’s president, Xi Jinping, called for the “annihilation” of excess developments. > As the Chinese landscape architect Yu Kongjian has pointed out, it also suffocates the ecosystems – fertile soil, self-cleansing streams, storm-resisting mangrove swamps, flood-preventing forests – on which human beings ultimately depend. It is a threat to what he calls “eco-security”. > Beijing’s much-vaunted Belt and Road Initiative – an overseas infrastructure investment project many times greater than the Marshall Plan – promises a splurge of roads in Kazakhstan, at least 15 dams in Africa, railways in Brazil and ports in Pakistan, Greece and Sri Lanka. To supply these and other projects, China National Building Material – the country’s biggest cement producer – has announced plans to construct 100 cement factories across 50 nations. Plus paragraphs about the aesthetics (or lack thereof) of a concrete jungle, the sentiments of people surrounded by huge walls on the shores of Japan, and the vast corruption/mafia behind the construction/concrete industry.

fomine3 5y ago

For Asia/Brazil part, is it a problem of concretes? Anyway we need alternative to concretes, but waste corrupt building may happen even without concretes.

smitty1e 5y ago

> In the time it takes you to read this sentence, the global building industry will have poured more than 19,000 bathtubs of concrete Let's see. Google says 13ft² * 19000=247000ft² And someone uses 10sec to read the sentence Surface area of earth=5.49 × 10^15 ft² 10 * 60 * 60 * 24 * 365.25 = 315576000 bathtub-sentence-years 5490000000000000/247000/31557600 704.322276yrs until the planet is covered in concrete.

eesmith 5y ago
Quoting https://www.cnbc.com/2021/03/05/sand-shortage-the-world-is-running-out-of-a-crucial-commodity.html https://www.cnbc.com/2021/03/05/sand-shortage-the-world-is-r... : > The UN estimates that 4.1 billion tons of cement is produced every year, driven primarily by China See also https://www.statista.com/statistics/267364/world-cement-production-by-country/ https://www.statista.com/statistics/267364/world-cement-prod... . Concrete is about 2,000 kg/m³ - https://www.engineeringtoolbox.com/concrete-properties-d_1223.html https://www.engineeringtoolbox.com/concrete-properties-d_122... 704 years * 4.1 billion metric tons/year / (2,000 kg / m / m / m) / (510,064,472 km * km ) => 2.83 mm So, 704 years to cover the planet in 3mm of concrete. The article says "In a single year, there is enough to patio over every hill, dale, nook and cranny in England". I am not able to reproduce that. Using 130,279 km2 from https://en.wikipedia.org/wiki/Geography_of_England https://en.wikipedia.org/wiki/Geography_of_England (4.1 billion metric tons) / (2,000 kg / m / m / m) / (130,279 km * km) => 1.57 cm https://duckduckgo.com/?t=ffsb&q=concrete+patio+thickness&ia=web https://duckduckgo.com/?t=ffsb&q=concrete+patio+thickness&ia... suggests 4 inches is the minimum depth for a patio, or about 10 cm. Which means it would take about 6 years to patio England. FWIW, 4.1 billion metric tons/year * 10 seconds => 1.3 kilo tons 1.3 kilo tons / density of concrete => 650 kilo Liters 650 kL / 19,000 bathtubs => 32 liters per bathtub I doubt UK bathtubs are 32 L. I'm finding numbers like around 150-200 L for a bathtub - https://duckduckgo.com/?q=volume+of+a+bathtub+in+liters&t=ffsb&ia=web https://duckduckgo.com/?q=volume+of+a+bathtub+in+liters&t=ff... .
- smitty1e 5y ago
  How exactly we're curing all of this concrete over the ocean surface is left as an exercise for the straight-line approximation aficionado.