[nudephil (OP)]

Paul sent us this question:

I have read that the world is running out of river sand for building, and that desert sand is no good because the grains are spherical because of constantly being blown around. When folk play billiards, they use a triangle to hold the balls. Can something along those lines be designed (maybe some sort of sponge structure) which would hold the sand in place? Alternatively with all the heat in deserts during the day, concentrate it with mirrors so you have furnaces which can fuse the grains together, perhaps with some binder. You'd get fulgurites which could be crushed and used in the normal way as river sand.

Anyone care to comment?

[alancalverd]

Old buildings make cheap ballast. Problem is that it takes a lot of fossil fuel to make cement, so we'll probably have to stop using the stuff anyway.

[pensador]

Paul sent us this question:

I have read that the world is running out of river sand for building, and that desert sand is no good because the grains are spherical because of constantly being blown around. When folk play billiards, they use a triangle to hold the balls. Can something along those lines be designed (maybe some sort of sponge structure) which would hold the sand in place? Alternatively with all the heat in deserts during the day, concentrate it with mirrors so you have furnaces which can fuse the grains together, perhaps with some binder. You'd get fulgurites which could be crushed and used in the normal way as river sand.

Anyone care to comment?

The world is not running out of sand and desert sand is perfectly useable, if it is full of salt it might need washing first to reduce the salt content. Where I live they use (araia do mar) sand from the sea and wash it to reduce the salt content. It is not as clean as river sand, but it works with few problems, if washed properly. I do however notice in some older houses or those worked on by dodgy builders they have used less clean cheaper sand, there is an issue with salt in the walls.

You could always recycle glass and use that in your concrete structures, it even looks pretty. Fine volcanic ash can be a good substitute for sand.

If the world was to run out of sand, we could always go back to wattle and daub, or just build houses without cement, the old fashioned way. There are plenty of different building materials to use, wood works well in many parts of the world. Different building materials are good for different applications. Wood for example would not be for a nuclear reactor

[alancalverd]

Washed sea sand is OK but expensive. Like the man said, however, most desert sand is unsuitable for mortar or concrete as the surface sand and blown dunes are "soft", with rounded faces and a high dust content - it has its uses but the sand/cement matrix has very little strength. Building sand needs to be coarse "sharp" material with little dust. The UK is, or at least used to be, a major exporter of estuary sand to desert countries.

[pensador]

All building materials should ideally confirm to the relevant EU/international standards, and should be suitable for the application, in mind. It is only through having standards can we guarantee the quality of the finished goods.
A lot of desert sand is coarse grained, and is suitable for construction.

A lot of trading ships often used sand as ballast? Which companies shipped sand commercially.

It is normal for sand to be characterized for physical and chemical properties inline with the relevant standards.
In the UK we currently have EU standards, which are probably similar to the older British Standards, but possibly not available electronically.

[Petrochemicals]

All building materials should ideally confirm to the relevant EU/international standards, and should be suitable for the application, in mind. It is only through having standards can we guarantee the quality of the finished goods.
A lot of desert sand is coarse grained, and is suitable for construction.

A lot of trading ships often used sand as ballast? Which companies shipped sand commercially.

It is normal for sand to be characterized for physical and chemical properties inline with the relevant standards.
In the UK we currently have EU standards, which are probably similar to the older British Standards, but possibly not available electronically.

Coarse is different to sharp. But rounded sand is acceptable for building, only thing is it takes more cement  to get the same result. 100 percent cement is possible, very strong but is expensive. Aggregates are used as fill rather than a constituent strengthener in cement.

Edit

Also if you have ever wondered about the running out of rock and stuff for building, when you see a major mountain range you think differently.

[rattentodcm]

Where I live they use (araia do mar) sand from the sea and wash it to reduce the salt content. It is not as clean as river sand, but it works with few problems, if washed properly. I do however notice in some older houses or those worked on by dodgy builders they have used less clean cheaper sand, there is an issue with salt in the walls.

Where I live they use (araia do mar) sand from the sea and wash it to reduce the salt content. It is not as clean as river sand, but it works with few problems, if washed properly. I do however notice in some older houses or those worked on by dodgy builders they have used less clean cheaper sand, there is an issue with salt in the walls.