<p>The top twelve cement producing countries <a href="https://www.statista.com/statistics/267364/world-cement-production-by-country/" rel="noreferrer">in 2020</a> produced 3191 Mt of cement. Increase this to 4000 Mt to include the rest of the world.</p>
<p>Depending on the application, the <a href="https://civiconcepts.com/blog/water-cement-ratio" rel="noreferrer">water to cement ratio of concrete</a> is between 0.4 and 0.6.</p>
<p>Assuming the worst case scenario of 0.6, then 2400 Mt of water was locked in concrete in 2020.</p>
<p>Now, 1 t of water occupies 1 m<sup>3</sup>, which is the same a 1000 L (1 kL). This means 2400 million cubic meters of water (2.4(10)<sup>12</sup> L, or 2.4 TL, or 2400 GL) was locked in concrete in 2020.</p>
<p>Another way of looking at it is, 2400 million cubic meters is 2.4 km<sup>3</sup>, which is a minuscule fraction of the total <a href="https://ngdc.noaa.gov/mgg/global/etopo1_ocean_volumes.html" rel="noreferrer">volume of the worlds oceans</a>, which is 1,335,000,000 km<sup>3</sup>.</p>

CC BY-SA 4.0
2022-03-31T22:14:06.133Z
Very neat, and perfect way of responding to adjectival opinion. Work out the numbers.
Anton
CC BY-SA 4.0
2022-04-01T00:13:51.877Z
That's about 7 micrometers per year of reduced sea level
Alice Monday
CC BY-SA 4.0
2022-04-01T01:32:29.623Z
As a point of comparison, that's about three hours' flow of the Amazon River.
Mark
CC BY-SA 4.0
2022-04-01T07:41:09.290Z
Just one final point missing to answer the question: at current rates, around 556 million years to empty the oceans (and a fraction of that until the situation "becomes grave").  However, _locally_ the situation may of course be grave even if in total the planet has more than enough (salt) water (can concrete plants work with salt water?)
gerrit
CC BY-SA 4.0
2022-04-01T09:42:39.273Z
The 0.4-0.6 figure is for the concrete mixture and does not include water consumed in the process in this video (goes on for 10-14 days and is called "curing"): https://youtu.be/3j1W_rHbVIg?

Is oceanic water being used in curing of concrete in construction work? If that doesn't affect the build life, still, oceanic water can't be transported to distant metropolis. The concern is about depletion of fresh/usable water resources, which (AFAIK) accounts only for about 3% of the total water reserves on the planet.
lousycoder
CC BY-SA 4.0
2022-04-01T09:58:23.537Z
@lousycoder [seawater can be used in concrete in some cases](https://www.sciencedirect.com/science/article/pii/S0950061818323055) - steel reinforcement doesn't like salt
Chris H
CC BY-SA 4.0
2022-04-01T12:59:44.410Z
I'm not doing the maths, but I bet we make more water through combustion with all the stuff we burn
ScottishTapWater
CC BY-SA 4.0
2022-04-01T16:18:12.817Z
Ocean water is transported to metropolises via rain. Ocean water evaporates to form clouds & wind transports the clouds everywhere. Fresh water sources on land are replenished by rain. It's an integral part of the water cycle. Also, any additional water used in the manufacturing of concrete is still going to be a minuscule amount of the total water on the surface of the planet.
Fred
CC BY-SA 4.0
2022-04-01T16:36:26.243Z
@Persistence: Very good point! All the hydrocarbons, such as coal, oil & gas, that are burned to produce energy, whether it be in power stations, cars or whatever all produce carbon dioxide (CO2) & water (H2O), such as methane (CH4, where CH4 + 3O2 -> CO2 + 2H2O.
Fred
CC BY-SA 4.0
2022-04-01T16:40:14.420Z
@gerrit: Some concrete can use salt water, but sea water can also be desalinated if needed. Earth desalinates sea water via the evaporation of sea water & the formation of rain clouds. Oceans are the ultimate source all all our fresh water resources.
Fred
CC BY-SA 4.0
2022-04-01T17:55:48.163Z
@Fred "Lucky" us -- all the CO2 released in making, transporting, and curing concrete helps warm the climate, melting polar ice and replenishing the liquid water supply!
jeffronicus
CC BY-SA 4.0
2022-04-01T19:33:33.793Z
Over those kind of geological timescales, the concrete will become carbonated as well and water liberated and CO2 captured.
Dan
CC BY-SA 4.0
2022-04-01T19:47:35.633Z
@Persistence It looks like for every 2 molecules of octane (I'll just assume gasoline is all octane) combusted, 18 molecules of water are produced. There are ~6.15 moles of octane in a liter, so one liter of gasoline burnt produces almost exactly one liter of water. 562 billion liters of gasoline are consumed in a year, so about 23% of the water lost to concrete production is made up for just by combustion of gasoline (not gonna bother doing the calculations for natural gas, coal, wood, etc.,)
rydwolf
CC BY-SA 4.0
2022-04-01T20:47:26.023Z
@RadvylfPrograms - Legend... If gasoline does 23%, then I'm pretty confident we make up for the rest
ScottishTapWater
CC BY-SA 4.0
2022-04-01T21:31:14.083Z
Comparing to total water is not as meaningful as comparing to freshwater. I've been told freshwater represents between 1% and 2% of accessible water and the very-large-number analysis you've provided would still apply. You might [rightly] point out that the ocean won't stop evaporating, but we also won't stop making concrete. The water for concrete comes from our freshwater budget, and that would be the salient comparison.
user121330
CC BY-SA 4.0
2022-03-31T17:55:27.793Z
2022-03-31T17:55:27.793Z
Fred
<p>Concrete loses some minute water over time. It's undergoing curing....however for most part, Concrete does not harden by evaporation, it hardens by a chemical process called hydration. The water added to concrete mix becomes a part of the concrete and never leaves concrete or evaporates,in essence becoming a new substance.<br />
As a whole average water use is 82.8 liters per ton, with 365 billion liters used yearly...
According to researchers, Global concrete production and totals since 1900, Humanity has produced 549 Gigatons (billion) of Concrete, using 12 TRILLION gallons of water.
Oceans water mass is 1.4 × 10^21 kg or 1.4 Quintillion tonnes. Human concrete use in a Century used 1/2,500,000th of the Earths water.
Comparison: If you have a 1 gallon jug of water representing ALL water on Earth, You've used ONE drop.</p>

CC BY-SA 4.0
2022-04-05T07:42:18.637Z
2022-04-05T07:42:18.637Z
LazyReader
<p>Not to worry, the gas burned in the kiln to produce the cement produces an offsetting amount of water.</p>

CC BY-SA 4.0
2022-05-31T15:51:35.267Z
You make a very good point... the [balanced combustion reaction for octane](https://en.intl.chemicalaid.com/tools/equationbalancer.php?equation=C8H18+%2B+O2+%3D+CO2+%2B+H2O) shows a bit more H2O is released than CO2.  And https://en.wikipedia.org/wiki/Cement_kiln suggests cement kiln's are responsible for 2.5% of anthropogenic CO2 emissions :-o  Even if cement were created with different fuel sources, it seems we're releasing much more stored up H2O globally than we're storing back up in concrete.
JeopardyTempest
CC BY-SA 4.0
2022-06-01T09:24:24.837Z
(to be clear to my comment: more H2O than CO2 by quantity measures, like volume [for gases]/moles/ppm, not by mass)
JeopardyTempest
CC BY-SA 4.0
2022-06-01T23:59:46.213Z
I was only saying it is a substantial source for water  If you want more water ,figure how much water is produced by burning diesel and gasoline to quarry, crush, and  process gravel and sand for the concrete.
blacksmith37
CC BY-SA 4.0
2022-05-31T15:15:56.547Z
2022-05-31T15:15:56.547Z
blacksmith37
<p>Global sea level rise is an increasing problem that governments are struggling to find a solution to. Sea level rise is mostly caused by ice sheets, and other permanent snow/ice, melting and a little by expansion of the sea due to higher temperatures. If sea level rise could be mitigated by use of concrete I assume this would have been mentioned in the IPCC reports. Overall I cannot imagine that what you suggest is a serious problem or likely to become one.</p>

CC BY-SA 4.0
2022-03-31T15:23:07.603Z
2022-03-31T15:23:07.603Z
Mehmet Karatay
<p>Concrete is the key ingredient to building housing, roads, and all kinds of infrastructure. Curing of concrete makes sure that the infra is rock solid and reliably durable and safe. But, it also consumes humongous amounts of water irreversibly, and this water is not returning to the ecosystem of water cycle.</p>
<p>Till how many years can we carry this on until the situation becomes grave?</p>

CC BY-SA 4.0
2022-03-31T15:23:42.357Z
Probably not a bad idea but my answer below is from an earth science perspective.
Mehmet Karatay
CC BY-SA 4.0
2022-04-01T07:42:33.193Z
What exactly do you mean by "the situation becomes grave"?  Water is far from equally distributed, and the boundary for a grave situation in Sudan is very different from the boundary for a grave situation in Norway.
gerrit
CC BY-SA 4.0
2022-04-01T09:45:38.240Z
@gerrit exactly. Usable water is a basic resource, and even if we use oceanic desalination for fulfilling the needs, I think that the process is neither net water positive or energy positive.
lousycoder
CC BY-SA 4.0
2022-04-01T09:51:48.850Z
@lousycoder If considering the local situation, the question is too broad.  Depending on location, the answer varies from 0 (concrete production infeasible already today due to lack of water) to forever (lack of water will never become an issue).
gerrit
CC BY-SA 4.0
2022-04-01T09:55:56.230Z
I'm wondering how much water is released in the concrete-making process (e.g. as vapour) in proportion to the liquid water consumed.  Some of the input minerals hold a fair bit of water before being heated.
Chris H
<water><water-table><urban-climate>
How do we compensate the water that is being taken out of water cycle for curing of concrete in infra construction?
lousycoder
# How do we compensate the water that is being taken out of water cycle for curing of concrete in infra construction?

(Asked by: username_0 on 2022-03-31)

Concrete is the key ingredient to building housing, roads, and all kinds of infrastructure. Curing of concrete makes sure that the infra is rock solid and reliably durable and safe. But, it also consumes humongous amounts of water irreversibly, and this water is not returning to the ecosystem of water cycle.

Till how many years can we carry this on until the situation becomes grave?

**Tags:** water, water-table, urban-climate

> **Comments:**
> **username_1**: Probably not a bad idea but my answer below is from an earth science perspective.  
> **username_2**: What exactly do you mean by "the situation becomes grave"?  Water is far from equally distributed, and the boundary for a grave situation in Sudan is very different from the boundary for a grave situation in Norway.  
> **username_0**: @username_2 exactly. Usable water is a basic resource, and even if we use oceanic desalination for fulfilling the needs, I think that the process is neither net water positive or energy positive.  
> **username_2**: @username_0 If considering the local situation, the question is too broad.  Depending on location, the answer varies from 0 (concrete production infeasible already today due to lack of water) to forever (lack of water will never become an issue).  
> **username_3**: I'm wondering how much water is released in the concrete-making process (e.g. as vapour) in proportion to the liquid water consumed.  Some of the input minerals hold a fair bit of water before being heated.  

---

## 4 answers

### Answer by username_4 on 2022-03-31. Score: 10

The top twelve cement producing countries [in 2020](https://www.statista.com/statistics/267364/world-cement-production-by-country/) produced 3191 Mt of cement. Increase this to 4000 Mt to include the rest of the world.

Depending on the application, the [water to cement ratio of concrete](https://civiconcepts.com/blog/water-cement-ratio) is between 0.4 and 0.6.

Assuming the worst case scenario of 0.6, then 2400 Mt of water was locked in concrete in 2020.

Now, 1 t of water occupies 1 m3, which is the same a 1000 L (1 kL). This means 2400 million cubic meters of water (2.4(10)12 L, or 2.4 TL, or 2400 GL) was locked in concrete in 2020.

Another way of looking at it is, 2400 million cubic meters is 2.4 km3, which is a minuscule fraction of the total [volume of the worlds oceans](https://ngdc.noaa.gov/mgg/global/etopo1_ocean_volumes.html), which is 1,335,000,000 km3.

> **Comments:**
> **username_5**: Very neat, and perfect way of responding to adjectival opinion. Work out the numbers.  
> **username_6**: That's about 7 micrometers per year of reduced sea level  
> **username_7**: As a point of comparison, that's about three hours' flow of the Amazon River.  
> **username_2**: Just one final point missing to answer the question: at current rates, around 556 million years to empty the oceans (and a fraction of that until the situation "becomes grave").  However, _locally_ the situation may of course be grave even if in total the planet has more than enough (salt) water (can concrete plants work with salt water?)  
> **username_0**: The 0.4-0.6 figure is for the concrete mixture and does not include water consumed in the process in this video (goes on for 10-14 days and is called "curing"): https://youtu.be/3j1W_rHbVIg?  Is oceanic water being used in curing of concrete in construction work? If that doesn't affect the build life, still, oceanic water can't be transported to distant metropolis. The concern is about depletion of fresh/usable water resources, which (AFAIK) accounts only for about 3% of the total water reserves on the planet.  
> **username_3**: @username_0 [seawater can be used in concrete in some cases](https://www.sciencedirect.com/science/article/pii/S0950061818323055) - steel reinforcement doesn't like salt  
> **username_8**: I'm not doing the maths, but I bet we make more water through combustion with all the stuff we burn  
> **username_4**: Ocean water is transported to metropolises via rain. Ocean water evaporates to form clouds & wind transports the clouds everywhere. Fresh water sources on land are replenished by rain. It's an integral part of the water cycle. Also, any additional water used in the manufacturing of concrete is still going to be a minuscule amount of the total water on the surface of the planet.  
> **username_4**: @Persistence: Very good point! All the hydrocarbons, such as coal, oil & gas, that are burned to produce energy, whether it be in power stations, cars or whatever all produce carbon dioxide (CO2) & water (H2O), such as methane (CH4, where CH4 + 3O2 -> CO2 + 2H2O.  
> **username_4**: @username_2: Some concrete can use salt water, but sea water can also be desalinated if needed. Earth desalinates sea water via the evaporation of sea water & the formation of rain clouds. Oceans are the ultimate source all all our fresh water resources.  
> **username_9**: @username_4 "Lucky" us -- all the CO2 released in making, transporting, and curing concrete helps warm the climate, melting polar ice and replenishing the liquid water supply!  
> **username_10**: Over those kind of geological timescales, the concrete will become carbonated as well and water liberated and CO2 captured.  
> **username_11**: @Persistence It looks like for every 2 molecules of octane (I'll just assume gasoline is all octane) combusted, 18 molecules of water are produced. There are ~6.15 moles of octane in a liter, so one liter of gasoline burnt produces almost exactly one liter of water. 562 billion liters of gasoline are consumed in a year, so about 23% of the water lost to concrete production is made up for just by combustion of gasoline (not gonna bother doing the calculations for natural gas, coal, wood, etc.,)  
> **username_8**: @RadvylfPrograms - Legend... If gasoline does 23%, then I'm pretty confident we make up for the rest  
> **username_12**: Comparing to total water is not as meaningful as comparing to freshwater. I've been told freshwater represents between 1% and 2% of accessible water and the very-large-number analysis you've provided would still apply. You might [rightly] point out that the ocean won't stop evaporating, but we also won't stop making concrete. The water for concrete comes from our freshwater budget, and that would be the salient comparison.  

---

### Answer by username_13 on 2022-04-05. Score: 2

Concrete loses some minute water over time. It's undergoing curing....however for most part, Concrete does not harden by evaporation, it hardens by a chemical process called hydration. The water added to concrete mix becomes a part of the concrete and never leaves concrete or evaporates,in essence becoming a new substance.  
As a whole average water use is 82.8 liters per ton, with 365 billion liters used yearly...
According to researchers, Global concrete production and totals since 1900, Humanity has produced 549 Gigatons (billion) of Concrete, using 12 TRILLION gallons of water.
Oceans water mass is 1.4 × 10^21 kg or 1.4 Quintillion tonnes. Human concrete use in a Century used 1/2,500,000th of the Earths water.
Comparison: If you have a 1 gallon jug of water representing ALL water on Earth, You've used ONE drop.


---

### Answer by username_14 on 2022-05-31. Score: 1

Not to worry, the gas burned in the kiln to produce the cement produces an offsetting amount of water.

> **Comments:**
> **username_15**: You make a very good point... the [balanced combustion reaction for octane](https://en.intl.chemicalaid.com/tools/equationbalancer.php?equation=C8H18+%2B+O2+%3D+CO2+%2B+H2O) shows a bit more H2O is released than CO2.  And https://en.wikipedia.org/wiki/Cement_kiln suggests cement kiln's are responsible for 2.5% of anthropogenic CO2 emissions :-o  Even if cement were created with different fuel sources, it seems we're releasing much more stored up H2O globally than we're storing back up in concrete.  
> **username_15**: (to be clear to my comment: more H2O than CO2 by quantity measures, like volume [for gases]/moles/ppm, not by mass)  
> **username_14**: I was only saying it is a substantial source for water  If you want more water ,figure how much water is produced by burning diesel and gasoline to quarry, crush, and  process gravel and sand for the concrete.  

---

### Answer by username_1 on 2022-03-31. Score: 1

Global sea level rise is an increasing problem that governments are struggling to find a solution to. Sea level rise is mostly caused by ice sheets, and other permanent snow/ice, melting and a little by expansion of the sea due to higher temperatures. If sea level rise could be mitigated by use of concrete I assume this would have been mentioned in the IPCC reports. Overall I cannot imagine that what you suggest is a serious problem or likely to become one.


---

