#granularmaterials — Public Fediverse posts

Running Out of Sand?

Headlines over the past few years have suggested that the world is running out of sand — specifically, that we’re running out of the angular sand grains preferred for concrete. Grady breaks down this idea in this Practical Engineering video, showing that the issue is more complicated than the shape of a sand grain. Yes, angular sand grains make stronger concrete than rounded ones for the same ingredient ratios. But concrete’s water content is also a major factor for strength, and rounded sand grains need less water to form a spreadable, workable concrete. Using less water also makes for stronger concrete.

And though we may be short on some types of sand in certain places, sand is a manufacturable substance. We have machines and processes capable of breaking rocks into sand. It’s more a matter of choosing between the economics of mining and manufacturing. (Video and image credit: Practical Engineering)

#civilEngineering #fluidDynamics #granularMaterials #physics #sand #science

Watch sand defy gravity and flow uphill thanks to “negative friction” - There's rarely time to write about every cool science-y story that comes... - https://arstechnica.com/?p=1980391 #12daysofchristmas #granularmaterials #collectivemotion #fluiddynamics #granularflow #engineering #science #physics

Tiny Jenga: Ants can sense which soil grains to remove when digging tunnels - Enlarge / Two ants tunneling in green gel. A new Caltech study found that ants se... - https://arstechnica.com/?p=1789021 #granularmaterials #antsareawesome #engineering #anttunnels #science #biology #physics

Cracking the case: New study sheds more light on the “Brazil nut effect” - (video link)
Open a can of mixed nuts, and chances are you'll find a bunch... - https://arstechnica.com/?p=1757826 #x-raycomputedtomography #granularconvection #granularmaterials #brazilnuteffect #science #physics