Focus on Cellulose ethers

Izakhiwo Zokunamathisela Usimende Kulungiswe I-Cellulose Ether

Izakhiwo Zokunamathisela Usimende Kulungiswe I-Cellulose Ether

Ngokulinganisa izakhiwo zemishini, izinga lokugcinwa kwamanzi, ukubeka isikhathi nokushisa kwe-hydration ye-cellulose ether ene-viscosities ehlukene kumithamo ehlukene yokunamathisela usimende, nokusebenzisa i-SEM ukuhlaziya imikhiqizo ye-hydration, umphumela we-cellulose ether ekusebenzeni kokunamathisela usimende kwaba. wafunda. umthetho wethonya. Imiphumela ibonisa ukuthi ukungezwa kwe-cellulose ether kungabambezela ukugeleza kukasimende, ukubambezeleka kokuqina kukasimende nokusetha, ukunciphisa ukukhululwa kokushisa kwe-hydration, kunwebe isikhathi sokubukeka kwesilinganiso sokushisa kwe-hydration, futhi umphumela wokuvinjelwa uyanda ngokunyuka komthamo kanye ne-viscosity. I-cellulose ether ingakhuphula izinga lokugcinwa kwamanzi odaka, futhi ingathuthukisa ukugcinwa kwamanzi odaka ngesakhiwo songqimba oluncane, kodwa uma okuqukethwe kudlula u-0.6%, ukwanda komphumela wokugcina amanzi akubalulekile; okuqukethwe kanye ne-viscosity yizici ezinquma i-cellulose eguquliwe usimende slurry. Ekusetshenzisweni kwe-cellulose ether modified mortar, umthamo kanye ne-viscosity kufanele kucatshangelwe ngokuyinhloko.

Amagama angukhiye:i-cellulose ether; umthamo; ukukhubazeka; ukugcinwa kwamanzi

 

Udaka lokwakha lungenye yezinto zokwakha ezidingekayo kumaphrojekthi wokwakha. Eminyakeni yamuva, ngokusetshenziswa okukhulu kwezinto zokufakwa odongeni kanye nokuthuthukiswa kwezidingo zokunqanda ukuqhekeka kanye ne-anti-seepage ezindongeni zangaphandle, kuye kwabekwa izidingo eziphakeme zokumelana nokuqhekeka, ukusebenza kwebhondi kanye nokusebenza kokwakhiwa kodaka. Ngenxa yokushiyeka kokushwabana okukhulu kokomisa, ukungagxili kahle, namandla ebhondi eqinile aphansi, udaka lwendabuko ngokuvamile alukwazi ukuhlangabezana nezidingo zokwakha, noma lubangele izinkinga ezifana nokuwa kwezinto zokuhlobisa. Njengodaka lokuplasta, ngoba udaka lulahlekelwa amanzi ngokushesha okukhulu, isikhathi sokusetha kanye nokuqina siyafinyezwa, futhi izinkinga ezinjengokuqhekeka nokubhoboza zenzeka ngesikhathi sokwakhiwa okukhulu, okuthinta kakhulu ikhwalithi yephrojekthi. Udaka lwendabuko lulahlekelwa amanzi ngokushesha okukhulu futhi ukufakwa kukasimende akwanele, okuholela ekuvuleni isikhathi esifushane sodaka lukasimende, okuyisihluthulelo sokuphazamisa ukusebenza kodaka.

I-Cellulose ether inomphumela omuhle wokuqina nokugcina amanzi, futhi iye yasetshenziswa kabanzi emkhakheni wodaka, futhi isibe yingxube ebaluleke kakhulu ukuze kuthuthukiswe ukugcinwa kwamanzi odaka futhi inikeze ukusebenza kokwakhiwa, ukunciphisa ngempumelelo ukwakhiwa kanye nokusetshenziswa kamuva kodaka lwendabuko. . Inkinga yokulahleka kwamanzi phakathi. I-Cellulose esetshenziselwa udaka ngokuvamile ihlanganisa i-methyl cellulose ether (MC), i-hydroxypropyl methyl cellulose (HPMC), i-hydroxyethyl methyl cellulose ether (HEMC), i-hydroxyethyl cellulose ether (HEC), njll. Phakathi kwazo, i-HPMC ne-HEMC yizona ezisetshenziswa kakhulu.

Leli phepha licwaninga ngokuyinhloko umphumela we-cellulose ether ekusebenzeni (izinga lokugcinwa kwamanzi, ukulahlekelwa kwamanzi nesikhathi sokusetha), izakhiwo zemishini (amandla acindezelayo namandla ebhondi eqinile), umthetho we-hydration kanye ne-microstructure yokunamathisela usimende. Ihlinzeka ngosekelo lwezakhiwo zikasimende oguquliwe we-cellulose ether futhi inikeza ireferensi yokusetshenziswa kwe-cellulose ether modified mortar.

 

1. Isivivinyo

1.1 Izinto ezisetshenziswayo

Usimende: Usimende Ojwayelekile wasePortland (PO 42.5) usimende okhiqizwe yi-Wuhan Yadong Cement Company, enendawo ethize engu-3500 cm.²/g.

I-Cellulose ether: i-hydroxypropyl methylcellulose ether etholakala ngokuthengiswayo (MC-5, MC-10, MC-20, viscosities of 50,000 Pa·S, 100000 Pa·S, 200000 Pa·S, ngokulandelana).

1.2 Indlela

Izici zemishini: Enqubweni yokulungiswa kwesampula, umthamo we-cellulose ether ngu-0.0% ~ 1.0% wesisindo sikasimende, futhi isilinganiso samanzi-samende ngu-0.4. Ngaphambi kokungeza amanzi nokugqugquzela, hlanganisa i-cellulose ether nosimende ngokulinganayo. Ukunamathisela usimende okunosayizi wesampula ka-40 x 40 x 40 kwasetshenziswa ukuze kuhlolwe.

Isikhathi sokusetha: Indlela yokulinganisa yenziwa ngokuya nge-GB/T 1346-2001 "Ukusetshenziswa Kwamanzi Okujwayelekile Okujwayelekile Kwesimende, Isikhathi Sokusetha, Indlela Yokuhlola Ukuzinza".

Ukugcinwa kwamanzi: Ukuhlolwa kokugcinwa kwamanzi okunamathiselwe usimende kubhekisela ku-DIN 18555 “indlela yokuhlola yodaka lwento ephilayo usimende”.

Ukushisa kwe-hydration: Ukuhlolwa kusebenzisa i-TAM Air microcalorimeter ye-TA Instrument Company yase-United States, futhi isilinganiso samanzi-simende ngu-0.5.

Umkhiqizo we-hydration: Hlanganisa amanzi ne-cellulose ether ngokulinganayo, bese ulungisa i-slurry kasimende, qala ukubeka isikhathi, thatha amasampula ngezikhathi ezihlukene, yeka ukugeleza kwamanzi nge-ethanol ephelele ukuze uhlolwe, futhi isilinganiso sikasimende samanzi singu-0.5.

 

2. Imiphumela kanye nengxoxo

2.1 Izakhiwo zemishini

Kusukela ethonyeni lokuqukethwe kwe-cellulose ether emandleni, kungabonakala ukuthi ngokwanda kokuqukethwe kwe-cellulose ether ye-MC-10, amandla we-3d, 7d no-28d wonke ayancipha; i-cellulose ether inciphisa amandla we-28d kakhulu. Kusukela ethonyeni le-cellulose ether viscosity emandleni, kungabonakala ukuthi kungakhathaliseki ukuthi i-cellulose ether ene-viscosity ye-50,000 noma i-100,000 noma i-200,000, amandla we-3d, i-7d, ne-28d izokwehla. Kungabonakala futhi ukuthi i-cellulose ether Viscosity ayinawo umthelela obalulekile emandleni.

2.2 Ukusetha isikhathi

Kusukela kumthelela wokuqukethwe kwe-100,000 viscosity cellulose ether ngesikhathi sokusetha, kungabonakala ukuthi ngokwanda kokuqukethwe kwe-MC-10, kokubili isikhathi sokuqala sokusetha kanye nesikhathi sokusetha sokugcina siyakhuphuka. Uma okuqukethwe kungu-1%, isikhathi sokuqala sokusetha Kufinyelele ku-510min, futhi isikhathi sokusetha sokugcina sifinyelele ku-850min. Uma kuqhathaniswa nokungenalutho, isikhathi sokuqala sokusetha sandiswa ngo-210min, futhi isikhathi sokugcina sokugcina sandiswa nge-470min.

Kusukela kumthelela we-cellulose ether viscosity ngesikhathi sokusetha, kungabonakala ukuthi noma ngabe i-MC-5, MC-10 noma i-MC-20, ingabambezela ukumiswa kukasimende, kodwa uma kuqhathaniswa nama-ether amathathu e-cellulose, isilungiselelo sokuqala. isikhathi nesilungiselelo sokugcina Isikhathi sikhula ngokukhula kwe-viscosity. Lokhu kungenxa yokuthi i-cellulose ether ingakhangiswa phezu kwezinhlayiya zikasimende, ngaleyo ndlela ivimbele amanzi ukuthi axhumane nezinhlayiya zikasimende, ngaleyo ndlela kubambezeleke ukugeleza kukasimende. Lapho i-viscosity ye-cellulose ether iba nkulu, yilapho ungqimba lwe-adsorption luba lukhudlwana endaweni yezinhlayiya zikasimende, futhi umphumela wokuhlehlisa uphawuleka nakakhulu.

2.3 Izinga lokugcinwa kwamanzi

Kusukela emthethweni wethonya wokuqukethwe kwe-cellulose ether esilinganisweni sokugcinwa kwamanzi, kungabonakala ukuthi ngokukhuphuka kokuqukethwe, izinga lokugcinwa kwamanzi odaka liyakhuphuka, futhi lapho okuqukethwe kwe-cellulose ether kungaphezu kuka-0.6%, izinga lokugcinwa kwamanzi liyakhuphuka. uzinzile esifundeni. Kodwa-ke, uma kuqhathaniswa nama-ether amathathu e-cellulose, kukhona umehluko emthonjeni we-viscosity ngenani lokugcinwa kwamanzi. Ngaphansi komthamo ofanayo, ubudlelwano phakathi kwezinga lokugcina amanzi yilokhu: MC-5MC-10MC-20.

2.4 Ukushisa kwe-hydration

Kusukela kumphumela wohlobo lwe-cellulose ether nokuqukethwe ekushiseni kwe-hydration, kungabonakala ukuthi ngokwanda kokuqukethwe kwe-MC-10, ukushisa okushisayo kwe-hydration kuncipha kancane kancane, futhi isikhathi sokushisa kwe-hydration esiphezulu sishintsha kamuva; Ukushisa kwe-hydration nakho kwaba nethonya elikhulu. Ngokukhula kwe-viscosity, ukushisa kwe-hydration kwehla kakhulu, futhi izinga lokushisa eliphakeme le-hydration lashintsha kakhulu kamuva. Kubonisa ukuthi i-cellulose ether ingabambezela ukusikwa kwe-cement, futhi umphumela wayo wokuhlehlisa uhlobene nokuqukethwe kanye ne-viscosity ye-cellulose ether, ehambisana nomphumela wokuhlaziya wokusetha isikhathi.

2.5 Ukuhlaziywa kwemikhiqizo ye-hydration

Kusukela ekuhlaziyweni kwe-SEM yomkhiqizo we-1d we-hydration, kungabonakala ukuthi uma i-0.2% MC-10 cellulose ether yengezwa, inani elikhulu le-clinker engenalutho kanye ne-ettringite ene-crystallization engcono ingabonakala. %, amakristalu e-ettringite ancishiswa kakhulu, okubonisa ukuthi i-cellulose ether ingabambezela ukugeleza kukasimende kanye nokwakhiwa kwemikhiqizo ye-hydration ngesikhathi esifanayo. Ngokuqhathanisa izinhlobo ezintathu ze-cellulose ethers, kungatholakala ukuthi i-MC-5 ingenza i-crystallization ye-ettringite emikhiqizweni ye-hydration ibe njalo, futhi i-crystallization ye-ettringite ijwayele kakhulu. okuhlobene nokushuba kongqimba.

 

3. Isiphetho

a. Ukwengezwa kwe-cellulose ether kuzobambezela ukugeleza kukasimende, kubambezele ukuqina nokumiswa kukasimende, kunciphise ukukhululwa kokushisa kwe-hydration, futhi kwandise isikhathi sokubukeka kwezinga lokushisa eliphakeme le-hydration. Ngokukhuphuka komthamo kanye ne-viscosity, umphumela wokuhlehlisa uzokhula.

b. I-Cellulose ether ingakhuphula izinga lokugcinwa kwamanzi odaka, futhi ingathuthukisa ukugcinwa kwamanzi kodaka ngohlaka olunongqimba oluncane. Ukugcinwa kwayo kwamanzi kuhlobene nomthamo kanye ne-viscosity. Uma umthamo udlula u-0.6%, umphumela wokugcina amanzi awukhuli kakhulu.


Isikhathi sokuthumela: Feb-01-2023
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