“Geopolymer Chemistry and Composition: A Comprehensive Review of Synthesis, Reaction Mechanisms, and Material Properties—Oriented with Sustainable Construction” #geopolymers #cements #materials #paper #toread
on 02026-01-15#video from #Misadventures-with-materials with a recipe for high-temperature calcium phosphate refractory #materials: triple superphosphate in the coffee grinder, slaked lime, and perlite (run through a food processor), 3.7 parts triple superphosphate (Ca(H₂PO₄)₂) to 1 part lime, mixed as powders, then mixed as equal volumes with the perlite, then pressed dry into a mold, then moistened under pressure, to keep bubbles from expanding from the heat and cracking the material apart. It expands when curing, so it’s better to have a mold you can take the sides off of. #cements #toread
on 02025-11-11more #video about #cements #materials which falls pretty far short of including enough information for reproducibility, talking about “bast” fiber without specifying what plant, confusing caliche with clay, misstatements (“portland has clay in it”, “those [lime and portland bound concretes] need oxygen to cure”), etc. He’s also very confused about #geopolymers. I’m amazed how many factual errors he was able to fit into a single 21-minute video. Where it’s not wrong, it’s super unclear. Also I thought this was going to be about MgO cements, because that’s what it says in the title, but he doesn’t say anything specific about MgO, except that I think he’s confusing it with Al₂O₃. #Plonk to "mrglasecki".
on 02025-11-11#video making Parkhomov-style magnesium #cements with MgO, ZnO, and waterglass to fix a broken firebrick #toread
on 02025-11-11#video #toread by #Murray-Smith on magnesium-oxide #cements, specifically Sorel oxychloride cement #materials
on 02025-11-11magnesium phosphate #cements #materials #toread
on 02025-11-11#video on building a shower with a magnesium-phosphate drain, using magnesium oxide, Mega Buds potassium phosphate fertilizer, and borax, used to stiffen burlap. #cements #materials
on 02025-11-1135' #video on magnesium phosphate #cements #materials for airfield pavements for enhanced corrosion resistance and heat resistance by a guy whose product has been in service at Cannon Air Force Base for three years now. Apparently leaked lubricants were somehow forming phosphoric acid in the jet wash, which ate the concrete. Magnesium-phosphate pothole fillers were immune. Magnesium oxide (light, hard, or dead burned), ammonium or potassium phosphate salts, fly ash (40–60%) and boric acid to retard the reaction (though boric acid degrades the strength, by about 25% at 3% boric acid), and water. The set cement is struvite-K (MgKPO₄). He mentions that any unreacted phosphates are highly soluble, making porous concrete after they leach out. See ERDC Technical Report 20-12 from 02020 by Ramsey, Scott, Weiss, and Tingle. #toread
on 02025-11-11