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cement is the binder, usually made of lime, which is mined from limestone. concrete is cement plus other materials such as gravel. stones are naturally formi

cement is the binder, usually made of lime, which is mined from limestone. concrete is cement plus other materials such as gravel. stones are naturally forming solids made from minerals. this should help get you started. wikipedia is your friend.

ogogmad 4y ago
I've looked this stuff up on Wikipedia before asking. There's too much information. A bit like your answer: Detail without explanation. It's like wading through descriptions of gear mechanisms before learning what a wristwatch is. This article got the closest to answering my question: https://www.thespruce.com/difference-between-cement-concrete-and-mortar-2130884 https://www.thespruce.com/difference-between-cement-concrete... The summary is that cement is a constituent of mortar and concrete, which is never used on its own, but is only used to make the latter two. Mortar is used to "glue" bricks together. Concrete is a substance which can be made into lots of different shapes before hardening. Where is the summary misleading? [edit: Changed the word "cement" in the 2nd last sentence to "concrete". That was an accident.]
- HPsquared 4y ago
  Concrete is cement + sand + stones. It's basically stones held together by mortar. You need to have a sufficient range of particle sizes to fill in the gaps between the stones. An individual stone is strong and has no voids. A pile of stones is weak because it has voids, the stones can roll around each other, and don't have much contact area. In concrete (and asphalt, etc.) the voids between the large stones are filled with sand. The gaps between the sand grains are then filled with cement, which is even finer. You end up with a solid mass of material with minimal voids and all the particles fixed in place. Concrete is stronger than mortar because a larger portion of it is solid material (the interior of the stones is solid, whereas the "mortar" contains voids between the sand grains).
  - ogogmad 4y ago
    Thanks. Combined with https://news.ycombinator.com/item?id=32116807 https://news.ycombinator.com/item?id=32116807, this is a very helpful answer.
  - carapace 4y ago
    There's also "aircrete" which is basically foamed cement. Air bubbles take the places of stones and sand. > Foam concrete, also known as Lightweight Cellular Concrete (LCC), Low Density Cellular Concrete (LDCC), and other terms is defined as a cement-based slurry, with a minimum of 20% (per volume) foam entrained into the plastic mortar.[1] As mostly no coarse aggregate is used for production of foam concrete the correct term would be called mortar instead of concrete https://en.wikipedia.org/wiki/Aircrete https://en.wikipedia.org/wiki/Aircrete It's pretty crazy stuff. It's light enough that it floats on water, and it's waterproof. It's also fireproof, as well as bug-proof and mold- and mildew-resistant. It's very durable but you can work it with hand tools, saw it, drill it, etc. It takes nails. It's also a great insulator. There are folks who figured out how to make backyard-scale foamers for ~$100 of parts from any hardware store, and they make these beautiful aircrete dome homes: https://www.domegaia.com/ https://www.domegaia.com/ I've also seen companies that manufacture large aircrete bricks that are assembled onsite like giant LEGO blocks.

ogogmad 4y ago

I've looked this stuff up on Wikipedia before asking. There's too much information. A bit like your answer: Detail without explanation. It's like wading through descriptions of gear mechanisms before learning what a wristwatch is. This article got the closest to answering my question: https://www.thespruce.com/difference-between-cement-concrete-and-mortar-2130884 https://www.thespruce.com/difference-between-cement-concrete... The summary is that cement is a constituent of mortar and concrete, which is never used on its own, but is only used to make the latter two. Mortar is used to "glue" bricks together. Concrete is a substance which can be made into lots of different shapes before hardening. Where is the summary misleading? [edit: Changed the word "cement" in the 2nd last sentence to "concrete". That was an accident.]

HPsquared 4y ago
Concrete is cement + sand + stones. It's basically stones held together by mortar. You need to have a sufficient range of particle sizes to fill in the gaps between the stones. An individual stone is strong and has no voids. A pile of stones is weak because it has voids, the stones can roll around each other, and don't have much contact area. In concrete (and asphalt, etc.) the voids between the large stones are filled with sand. The gaps between the sand grains are then filled with cement, which is even finer. You end up with a solid mass of material with minimal voids and all the particles fixed in place. Concrete is stronger than mortar because a larger portion of it is solid material (the interior of the stones is solid, whereas the "mortar" contains voids between the sand grains).
- ogogmad 4y ago
  Thanks. Combined with https://news.ycombinator.com/item?id=32116807 https://news.ycombinator.com/item?id=32116807, this is a very helpful answer.
- carapace 4y ago
  There's also "aircrete" which is basically foamed cement. Air bubbles take the places of stones and sand. > Foam concrete, also known as Lightweight Cellular Concrete (LCC), Low Density Cellular Concrete (LDCC), and other terms is defined as a cement-based slurry, with a minimum of 20% (per volume) foam entrained into the plastic mortar.[1] As mostly no coarse aggregate is used for production of foam concrete the correct term would be called mortar instead of concrete https://en.wikipedia.org/wiki/Aircrete https://en.wikipedia.org/wiki/Aircrete It's pretty crazy stuff. It's light enough that it floats on water, and it's waterproof. It's also fireproof, as well as bug-proof and mold- and mildew-resistant. It's very durable but you can work it with hand tools, saw it, drill it, etc. It takes nails. It's also a great insulator. There are folks who figured out how to make backyard-scale foamers for ~$100 of parts from any hardware store, and they make these beautiful aircrete dome homes: https://www.domegaia.com/ https://www.domegaia.com/ I've also seen companies that manufacture large aircrete bricks that are assembled onsite like giant LEGO blocks.