1. Zafin ruwa
Dangane da yanayin sakin zafi na hydration na tsawon lokaci, tsarin hydration na siminti yawanci yakan kasu kashi biyar, wato, lokacin lokacin hydration na farko (0 ~ 15min), lokacin shigar (15min ~ 4h), lokacin haɓakawa da saita lokaci (4h ~ 8h), raguwa da lokacin hardening (8h ~ 24h), da lokacin warkewa (1d ~ 28).
Sakamakon gwajin ya nuna cewa a farkon matakin ƙaddamarwa (watau lokacin farkon hydration), lokacin da adadin HEMC ya kasance 0.1% idan aka kwatanta da slurry na siminti mara kyau, an haɓaka kololuwar slurry kuma mafi girma yana ƙaruwa sosai. Lokacin da adadinHEMCyana ƙaruwa zuwa Lokacin da yake sama da 0.3%, farkon exothermic ganiya na slurry yana jinkiri, kuma ƙimar ƙimar a hankali yana raguwa tare da haɓaka abun ciki na HEMC; A bayyane yake HEMC zai jinkirta lokacin ƙaddamarwa da lokacin hanzari na slurry siminti, kuma mafi girman abun ciki, mafi tsayin lokacin ƙaddamarwa, da ƙarin lokacin haɓaka baya baya, kuma ƙarami mafi girma na exothermic; Canjin abun ciki na ether cellulose ba shi da wani tasiri mai tasiri akan tsawon lokacin raguwa da lokacin kwanciyar hankali na ciminti slurry, kamar yadda aka nuna a cikin Hoto 3 (a) An nuna cewa ether cellulose kuma zai iya rage zafi na hydration na simintin siminti a cikin sa'o'i 72, amma lokacin da zafi na hydration ya fi tsawon sa'o'i 36, canjin abun ciki na hydration yana da tasiri mai yawa kamar yadda ciminti yana da tasiri mai tasiri a kan hydration. Hoto na 3 (b).
Fig.3 Bambance-bambancen yanayin sakin zafi na hydration na siminti manna tare da abun ciki daban-daban na ether cellulose (HEMC)
2. Mechanical Properties:
Ta hanyar nazarin nau'ikan ethers na cellulose guda biyu tare da danko na 60000Pa·s da 100000Pa·s, an gano cewa ƙarfin matsawa na turmi da aka gyara wanda aka haɗe da methyl cellulose ether ya ragu sannu a hankali tare da haɓaka abun ciki. Ƙarfin matsawa na turmi da aka gyara tare da 100000Pa·s viscosity hydroxypropyl methyl cellulose ether yana ƙaruwa da farko sannan kuma ya ragu tare da karuwar abun ciki (kamar yadda aka nuna a hoto 4). Ya nuna cewa haɗa methyl cellulose ether zai rage ƙarfin matsawa na turmi siminti. Mafi yawan adadin, ƙananan ƙarfin zai zama; ƙananan danko, mafi girman tasiri akan asarar ƙarfin turmi; hydroxypropyl methyl cellulose ether Lokacin da kashi bai wuce 0.1% ba, ƙarfin matsawa na turmi na iya ƙarawa yadda ya kamata. Lokacin da adadin ya fi 0.1%, ƙarfin matsawa na turmi zai ragu tare da karuwar adadin, don haka ya kamata a sarrafa sashi a 0.1%.
Hoto.4 3d, 7d da 28d ƙarfin matsawa na MC1, MC2 da MC3 da aka gyara turmi siminti
(Methyl cellulose ether, danko 60000Pa · S, daga baya ake magana a kai a matsayin MC1; methyl cellulose ether, danko 100000Pa·S, ake magana a kai a matsayin MC2; hydroxypropyl methylcellulose ether, danko 100000Pa · S, ake magana a kai a matsayin MC2).
3. Clokacin kuri'a:
Ta hanyar auna lokacin saitin hydroxypropyl methylcellulose ether tare da danko na 100000Pa·s a cikin nau'ikan nau'ikan siminti daban-daban, an gano cewa tare da karuwar adadin HPMC, lokacin saitin farko da lokacin saitin karshe na turmi siminti ya tsawaita. Lokacin da maida hankali shine 1%, lokacin saitin farko ya kai mintuna 510, kuma lokacin saitin ƙarshe ya kai mintuna 850. Idan aka kwatanta da samfurin babu, ana ƙara lokacin saitin farko da mintuna 210, kuma lokacin saitin ƙarshe yana ƙara da mintuna 470 (kamar yadda aka nuna a hoto na 5). Ko HPMC ne tare da danko na 50000Pa s, 100000Pa s ko 200000Pa s, zai iya jinkirta saitin siminti, amma idan aka kwatanta da ethers na cellulose guda uku, lokacin saitin farko da lokacin saitin karshe yana tsawaita tare da karuwar danko, kamar yadda aka nuna a cikin Hoto na 6. Wannan shi ne saboda cellulose ether yana daɗaɗɗen simintin siminti, wanda ke hana ruwa haɗuwa da siminti, don haka jinkirta jinkirin siminti. Mafi girman danko na ether cellulose, da kauri Layer adsorption a saman simintin barbashi, kuma mafi muhimmanci da retarding sakamako.
Fig.5 Tasirin abun ciki na ether cellulose akan saita lokacin turmi
Fig.6 Tasirin viscosities daban-daban na HPMC akan lokacin saitin siminti
(MC-5(50000Pa·s), MC-10(100000Pa·s) da MC-20(200000Pa·s))
Methyl cellulose ether da hydroxypropyl methyl cellulose ether zai ƙwarai tsawanta saitin lokaci na ciminti slurry, wanda zai iya tabbatar da cewa ciminti slurry yana da isasshen lokaci da ruwa ga hydration dauki, da kuma warware matsalar da low ƙarfi da marigayi mataki na ciminti slurry bayan hardening. matsalar fashewa.
4. Riƙe ruwa:
An yi nazarin tasirin abun ciki na ether cellulose akan riƙe ruwa. An gano cewa tare da karuwar abun ciki na ether cellulose, yawan adadin ruwa na turmi ya karu, kuma lokacin da abun ciki na ether cellulose ya fi 0.6%, yawan adadin ruwa ya kasance mai tsayi. Koyaya, idan aka kwatanta nau'ikan ethers cellulose guda uku (HPMC tare da danko na 50000Pa s (MC-5), 100000Pa s (MC-10) da 200000Pa s (MC-20)), tasirin danko akan riƙe ruwa ya bambanta. Dangantakar da ke tsakanin adadin riƙe ruwa shine: MC-5.
Lokacin aikawa: Afrilu-28-2024