Please note that high temperatures should not affect the fibers and make them brittle. Also, based on our knowledge, the glass fibers which are used in cementitious fireproofing materials must be resistant to alkaline environment.
Hello,
I made several test about fire resistance, specially using geopolymer binders that naturally are fireproof. I used different fibers for spraying tests and I noted these properties (tests made till 1300°C using propane flame):
- glass fibers , treated with superficial film that permitted them flexibility and of course alkali resistant, became brittle after 600-700 °C, but geopolymer binder protected from other damaging. Using a Portland cementitious binder sample exploded or was seriously damaged after the same temperature.
- poly propylene fibers , were very useful because after 450-600°C they burned but porosity that was so created (air ) permitted to gasses to move without creating big damaging. Even cementitious samples cracked but without exploding .
- basalt fibers , were produced at about 1200°C so in a geopolymer mortar remain stable , but if you use a Molar Ratio of silicate too low (user hostile so less than 1,45) very alcali ambient started to dissolve fibers. So fire wasn't an issue, on the contrary pH was necessary to be maintained on user friendly levels so about 13-13,2 with molar ratio higher till about 1,7-1,8 for this application. I tested potassium silicate , that showed better resistance and sodium silicate (was possible to use blends of silicates to this particular application with the best results). Using Portland cement, fibers maintained their properties but mortar was seriously damaged.
other fibers didn't show good performance when temperature increased . By the way I'm testing hemp fibers and they work incredibly good. There is only a problem of supplying because in Italy , this cheap fiber has still a niche market . At the moment I'm checking only geopolymer products with these fibers with the best results (no creeping).
Regards
Alex Reggiani
Можно в раствор добавлять волластонит и/или вермикулит.
Вермикулит природный материал. С его добавками можно наносить огнезащитное покрытие 1-3 мм. При высоких температурах вермикулит вспучивается и повышает огнестойкость конструкций на которые нанесено огнезащитное покрытие. При вспучивании толщина огнезащитного покрытия увеличивается до 3-4 см. Об этих моих исследованиях можно прочитать вот здесь https://elibrary.ru/item.asp?id=41039213
Кроме того огнезащищенность материалов могут повысить алкилфосфоновые кислоты, об этих моих исследованиях можно прочитать здесь - https://elibrary.ru/item.asp?id=30229681
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