Comments by "ke6gwf - Ben Blackburn" (@ke6gwf) on "Why The World Is Running Out Of Sand" video.

The report is wrong, using weathered sand and gravel seriously reduces the strength of the concrete. You want sharp sand straight from fresh crushed rocks at the quarry to make the best concrete. Anything else is weak BECAUSE of the rounded edges. And really? 10 tons of sand to make 1 ton of concrete?! Concrete is only about 1/3 sand, so that's just impossible!
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@bknesheim you have it backwards. Crushed aggregate is the best for making strong concrete, because the concrete bonds well to the sharp edges, and the aggregate doesn't want to slide on other pieces. When it's weathered, you lose a lot of strength from your mix, because it's smooth and doesn't have the grip potential. In the US where I have worked the cement plants are often right at the quarry, and the sand and gravel comes straight out of the crusher, and that's the mix specified by the standards.
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@drmodestoesq the crushed stone quarry sand is the best kind for making strong concrete, and last I checked we don't have any shortage on bedrock or mountains, so no sand shortage for making good concrete! (yes, you CAN make concrete from beach sand, but it's much weaker because of the smooth surface, as opposed to the sharp sand from a crusher.)
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This report has serious problems. Sand is about 1/3 of cement mix, so it's impossible to take 10 tons of sand to make 1 ton of concrete. And crushed stone sharp sand is the best for construction. Beach sand is too smooth and makes weak concrete. And we have no shortage of mountains to crush into sand for building construction! The places that use beach or river sand are making weak concrete, and just trying to save a buck, and they will adapt.
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