I-cellulose ether ku-morphology ye-ettringite yakuqala

Imiphumela ye-hydroxyethyl methyl cellulose ether kanye ne-methyl cellulose ether ku-morphology ye-ettringite ku-slurry kasimende wangaphambi kwesikhathi yacwaningwa ngokuskena i-electron microscopy (SEM). Imiphumela ibonisa ukuthi isilinganiso sobude be-diameter yamakristalu e-ettringite ku-hydroxyethyl methyl cellulose ether modified slurry sincane kunaleso esise-slurry esivamile, futhi i-morphology yamakristalu e-ettringite ifushane njengenduku. Isilinganiso sobude be-diameter yamakristalu e-ettringite ku-methyl cellulose ether eguquliwe slurry sikhulu kunaleso esise-slurry esijwayelekile, futhi i-morphology yamakristalu e-ettringite iyinduku yenaliti. Amakristalu e-ettringite kumaslurry kasimende ajwayelekile ane-aspect ratio endaweni ethile phakathi. Ngocwaningo lokuhlola olungenhla, kuphinde kucace ukuthi umehluko wesisindo samangqamuzana wezinhlobo ezimbili ze-cellulose ether iyisici esibaluleke kakhulu esithinta i-morphology ye-ettringite.

Amagama angukhiye:i-ettringite; Isilinganiso sobude bobubanzi; I-methyl cellulose ether; I-Hydroxyethyl methyl cellulose ether; i-morphology

I-Ettringite, njengomkhiqizo we-hydration owandiswe kancane, inomthelela omkhulu ekusebenzeni kukasimende, futhi ibilokhu iyisizinda socwaningo sezinto ezisekelwe kusimende. I-Ettringite iwuhlobo lwe-trisulfide ye-calcium aluminate hydrate, ifomula yayo yamakhemikhali ithi [Ca3Al (OH)6·12H2O]2·(SO4)3·2H2O, noma ingabhalwa ngokuthi 3CaO·Al2O3 ·3CaSO4·32H2O, evame ukufushaniswa ngokuthi AFt . Ohlelweni lukasimende lwasePortland, i-ettringite yakhiwa ngokuyinhloko ukusabela kwegypsum ngamaminerali e-aluminate noma i-ferric aluminate, edlala indima yokubambezela ukugeleza kwamanzi kanye namandla okuqala kasimende. Ukwakheka kanye ne-morphology ye-ettringite kuthintwa izici eziningi ezifana nezinga lokushisa, inani le-pH kanye nokugxila kwe-ion. Kusukela ngo-1976, uMetha et al. isebenzise imakroskopu ye-electron yokuskena ukuze itadishe izici ze-morphological ze-AFt, futhi yathola ukuthi i-morphology yemikhiqizo enjalo ye-hydration eyandisiwe yayihluke kancane lapho indawo yokukhula inkulu ngokwanele nalapho isikhala silinganiselwe. Eyokuqala yayingama-spherules azacile amise okwenduku, kanti lena yakamuva yayiyi-prism emifushane emise okwenduku. Ucwaningo luka-Yang Wenyan luthole ukuthi amafomu e-AFt ayehlukile ngendawo yokwelapha ehlukile. Izimo ezimanzi zizobambezela ukwenziwa kwe-AFt kukhonkolo onwetshiwe futhi kwandise amathuba okuvuvukala nokuqhekeka kukakhonkolo. Izimo ezihlukene azithinti kuphela ukwakheka kanye nesakhiwo esincane se-AFt, kodwa futhi nokuqina kwayo kwevolumu. U-Chen Huxing et al. ithole ukuthi ukuzinza kwesikhathi eside kwe-AFt kwehle ngokunyuka kokuqukethwe kwe-C3A. UClark noMonteiro et al. ithole ukuthi ngokwanda kokucindezela kwemvelo, isakhiwo sekristalu ye-AFt sishintshile ukusuka ekuhleleni kuya ekuphazamisekeni. U-Balonis no-Glasser babuyekeze izinguquko zokuminyana kwe-AFm ne-AFt. URenaudin et al. ifunde izinguquko zesakhiwo se-AFt ngaphambi nangemuva kokucwiliswa esixazululweni kanye nemingcele yesakhiwo se-AFt ku-Raman spectrum. Kunther et al. ifunde umphumela wokusebenzelana phakathi kwe-CSH gel calcium-silicon ratio ne-sulfate ion ku-AFt crystallization pressure nge-NMR. Ngesikhathi esifanayo, ngokusekelwe ekusetshenzisweni kwe-AFt ezintweni ezisekelwe kusimende, u-Wenk et al. ifunde i-AFt crystal orientation yesigaba sikakhonkolo ngokusebenzisa ubuchwepheshe bokuqeda ukuhlukana kwe-synchrotron ngemisebe ye-X-ray. Ukwakhiwa kwe-AFt kusimende oxubile kanye nendawo yocwaningo lwe-ettringite kwahlolisiswa. Ngokusekelwe ekubambezelekeni kokusabela kwe-ettringite, ezinye izazi zenze ucwaningo oluningi ngembangela yesigaba se-AFt.

Ukwandiswa kwevolumu okubangelwa ukwakheka kwe-ettringite ngezinye izikhathi kuyathandeka, futhi kungenza "njengokunweba" okufana ne-ejenti yokwandisa i-magnesium oxide ukuze kugcinwe ukuzinza kwevolumu yezinto ezisekelwe kusimende. Ukwengezwa kwe-emulsion ye-polymer kanye ne-emulsion powder e-dispersible kushintsha izakhiwo ze-macroscopic zezinto ezisekelwe ku-cement ngenxa yemiphumela yazo ebalulekile ku-microstructure yezinto ezisekelwe ku-samente. Kodwa-ke, ngokungafani nempushana ye-emulsion ehlakazeka kabusha ethuthukisa ngokuyinhloko impahla yokubopha yodaka oluqinile, i-polymer cellulose ether encibilikayo emanzini (CE) inikeza udaka olusanda kuxutshwa ukugcinwa kwamanzi okuhle nomphumela wokujiya, ngaleyo ndlela ithuthukise ukusebenza komsebenzi. I-Non-ionic CE ivame ukusetshenziswa, kufaka phakathi i-methyl cellulose (MC), i-hydroxyethyl cellulose (HEC), i-hydroxypropyl methyl cellulose (HPMC),i-hydroxyethyl methyl cellulose (HEMC), njll., futhi i-CE idlala indima odakeni olusanda kuxutshwa kodwa futhi ithinta inqubo ye-hydration yodaka lukasimende. Ucwaningo luye lwabonisa ukuthi i-HEMC ishintsha inani le-AFt elikhiqizwa njengomkhiqizo we-hydration. Kodwa-ke, azikho izifundo eziqhathanise ngokuhlelekile umphumela we-CE ku-microscopic morphology ye-AFt, ngakho-ke leli phepha lihlola umehluko womphumela we-HEMC ne-MC ku-microscopic morphology ye-ettringham ekuqaleni (usuku olungu-1) usimende slurry ngokuhlaziywa kwesithombe kanye ukuqhathanisa.

1. Isivivinyo

1.1 Izinto ezingavuthiwe

I-P·II 52.5R yasePortland usimende ekhiqizwe yi-Anhui Conch Cement Co., LTD yakhethwa njengosimende ekuhlolweni. Ama-ether amabili e-cellulose yi-hydroxyethyl methylcellulose (HEMC) ne-methylcellulose (methylcellulose, i-Shanghai Sinopath Group) ngokulandelanayo. MC); Amanzi okuxuba amanzi ampompi.

1.2 Izindlela zokuhlola

Isilinganiso samanzi-samente wesampula yokunamathisela usimende sasingu-0.4 (isilinganiso esikhulu samanzi kuya kusimende), futhi okuqukethwe kwe-cellulose ether kwakuyi-1% yesisindo sikasimende. Ukulungiswa kwesifanekiso kwenziwa ngokuvumelana ne-GB1346-2011 "Indlela Yokuhlola Yokusetshenziswa Kwamanzi, Isikhathi Sokusetha Nokuzinza Kwe-Cement Standard Consistency". Ngemva kokwenza isifanekiso, ifilimu yepulasitiki yafakwa phezu kwesikhunta ukuvimbela ukuhwamuka kwamanzi angaphezulu kanye ne-carbonization, futhi isifanekiso safakwa egumbini lokuphulukisa elinokushisa okungu-(20±2)℃ kanye nomswakama ohlobene no (60±5). ) %. Ngemuva kosuku olu-1, isikhunta sisusiwe, futhi isampula yaphulwa, bese isampula encane ithathwe phakathi futhi ifakwe ku-ethanol e-anhydrous ukuze kuqedwe ukugeleza kwamanzi, futhi isampula yakhishwa futhi yomiswa ngaphambi kokuhlolwa. Amasampula omisiwe anamathiselwe kuthebula lesampula ngokunamathelayo okunamahlangothi akabili, futhi ungqimba lwefilimu yegolide lwafafazwa phezulu ngethuluzi lokufafaza le-ion elizenzakalelayo le-Cressington 108auto. I-sputtering current yayingu-20 mA kanti isikhathi sokufafaza sasingu-60 s. I-FEI QUANTAFEG 650 I-electronic Scanning Microscope (ESEM) isetshenziselwe ukubuka izici ze-morphological ze-AFt esigabeni sesampula. Imodi ye-electron yesibili evacuum ephezulu yasetshenziswa ukubuka i-AFT. I-voltage yokusheshisa ingu-15 kV, ububanzi bendawo ye-beam bungu-3.0 nm, futhi ibanga lokusebenza lilawulwa cishe ku-10 mm.

2. Imiphumela kanye nengxoxo

Izithombe ze-SEM ze-ettringite ku-slurry kasimende oshintshiwe we-HEMC oqinile zibonise ukuthi ukukhula kokuma kwe-Ca (OH)2(CH) enengqimba kwakusobala, futhi i-AFt ibonise ukunqwabelana okungavamile kwe-AFt efana nenduku emfushane, futhi enye i-AFT efana nenduku emfushane yayimboziwe. ngesakhiwo solwelwesi lwe-HEMC. UZhang Dongfang et al. iphinde yathola i-AFt emfushane efana nenduku lapho ibheka izinguquko ze-microstructure ye-HEMC eguquliwe usimende slurry nge-ESEM. Babekholelwa ukuthi udaka oluvamile lukasimende lwasabela ngokushesha ngemva kokuhlangana namanzi, ngakho-ke ikristalu ye-AFt yayincane, futhi ukwandiswa kweminyaka yobudala be-hydration kwaholela ekwandeni okuqhubekayo kwesilinganiso sobude bobubanzi. Kodwa-ke, i-HEMC yandisa i-viscosity yesisombululo, yanciphisa izinga lokubopha ama-ion esixazululweni futhi yabambezela ukufika kwamanzi ebusweni bezinhlayiya ze-clinker, ngakho-ke isilinganiso sobude bobubanzi be-AFt sanda kumkhuba obuthakathaka futhi izici zayo ze-morphological zibonisiwe. umumo ofana nenduku emfushane. Uma kuqhathaniswa ne-AFt ku-slurry kasimende ojwayelekile weminyaka efanayo, le thiyori iqinisekiswe kancane, kodwa ayisebenzi ukuchaza izinguquko ze-AFt ku-MC modified Cement slurry. Izithombe ze-SEM ze-ettridite osukwini olungu-1 oluqinile lukasimende olulungiswayo lwe-MC ziphinde zabonisa ukukhula okuqondile kwe-Layer Ca(OH)2, ezinye izindawo ze-AFt nazo zambozwa ngesakhiwo sefilimu ye-MC, futhi i-AFt ibonise izici ze-morphological zokukhula kweqoqo. Kodwa-ke, uma kuqhathaniswa, i-AFt crystal ku-MC modified Cement slurry inesilinganiso esikhulu sobude bobubanzi kanye ne-morphology encane kakhulu, ebonisa i-acicular morphology evamile.

Kokubili i-HEMC ne-MC ibambezele inqubo yokuqala ye-hydration kasimende futhi yandisa i-viscosity yesisombululo, kodwa umehluko ezicini ze-AFt ze-morphological ezibangelwa yizo zazisabalulekile. Izenzakalo ezingenhla zingachazwa kabanzi ngombono wesakhiwo samangqamuzana e-cellulose ether kanye nesakhiwo sekristalu se-AFt. URenaudin et al. ocwiliswe i-AFt ehlanganisiwe esixazululweni se-alkali esilungisiwe ukuze "i-AFt ibe manzi", futhi wayisusa kancane futhi yomisa ebusweni besisombululo se-CaCl2 esigcwele (35% umswakama ohlobene) ukuze uthole "i-AFt eyomile". Ngemva kocwaningo lokucwengisiswa kwesakhiwo olwenziwa yi-Raman spectroscopy kanye ne-X-ray powder diffraction, kwatholakala ukuthi kwakungekho mehluko phakathi kwalezi zakhiwo ezimbili, kuphela ukuqondiswa kokwakheka kwekristalu kwamaseli okushintshile enqubweni yokomisa, okungukuthi, ohlelweni lwezemvelo. ukushintsha kusuka “kumanzi” kuya “komile”, amakristalu e-AFt akha amaseli ngendlela evamile yokwanda kancane kancane. Amakristalu e-AFt ngaku-c indlela evamile aye ancipha. Iyunithi eyisisekelo kakhulu yesikhala esinezinhlangothi ezintathu yakhiwe umugqa ojwayelekile, umugqa ojwayelekile ongu-b kanye nomugqa ojwayelekile ongu-c oncike komunye nomunye. Esimeni lapho okujwayelekile okungu-b kulungisiwe, amakristalu e-AFt ahlanganiswe ngendlela evamile, okuholela ekwandeni kwesigaba esiphambanayo seseli endizeni yezimiso ezijwayelekile. Ngakho-ke, uma i-HEMC "igcina" amanzi amaningi kune-MC, indawo "eyomile" ingenzeka endaweni yendawo, ikhuthaze ukuhlanganiswa kwe-lateral kanye nokukhula kwamakristalu e-AFt. Patural et al. ithole ukuthi ku-CE uqobo, izinga le-polymerization liphakeme (noma isisindo samangqamuzana sikhulu), i-viscosity ye-CE inkulu futhi kuba ngcono nokusebenza kokugcinwa kwamanzi. Isakhiwo samangqamuzana ama-HEMCs kanye ne-MCS sisekela le nkolelo-mbono, neqembu le-hydroxyethyl elinesisindo samangqamuzana esikhulu kakhulu kuneqembu le-hydrogen.

Ngokuvamile, amakristalu e-AFt azokwakheka futhi ahlehle kuphela uma ama-ion afanele efinyelela ekugcwalisweni okuthile ohlelweni lwesixazululo. Ngakho-ke, izici ezifana nokugxila kwe-ion, izinga lokushisa, inani le-pH kanye nesikhala sokwakheka kusixazululo sokuphendula singathinta kakhulu i-morphology yamakristalu e-AFt, futhi izinguquko ezimweni zokwenziwa zokwenziwa zingashintsha i-morphology yamakristalu e-AFt. Ngakho-ke, isilinganiso samakristalu e-AFt ku-slurry kasimende ovamile phakathi kokubili kungase kubangelwe isici esisodwa sokusetshenziswa kwamanzi ekufakweni kokuqala kukasimende. Nokho, umehluko ku-AFt crystal morphology obangelwa i-HEMC ne-MC kufanele ikakhulukazi ube ngenxa yendlela yabo ekhethekile yokugcina amanzi. I-Hemcs ne-MCS zakha “umzila ovaliwe” wokuthuthwa kwamanzi endaweni encane yodaka lukasimende olusha, okuvumela ukuba kube “isikhathi esifushane” lapho amanzi “kulula ukungena khona futhi kube nzima ukuphuma.” Kodwa-ke, phakathi nalesi sikhathi, indawo yesigaba soketshezi ngaphakathi naseduze kwe-microzone nayo iyashintshwa. Izinto ezifana nokugxiliswa kwe-ion, i-pH, njll., Ushintsho lwendawo yokukhula lubonakala nakakhulu kuzici ze-morphological zamakristalu e-AFt. Le "loop evaliwe" yokuthutha emanzini ifana nendlela yesenzo echazwe ngu-Pourchez et al. I-HPMC idlala indima yokugcina amanzi.

3. Isiphetho

(1) Ukwengezwa kwe-hydroxyethyl methyl cellulose ether (HEMC) kanye ne-methyl cellulose ether (MC) kungashintsha ngokuphawulekayo i-morphology ye-ettringite ekuqaleni (usuku olungu-1) oludaka olujwayelekile lukasimende.

(2) Ubude nobubanzi bekristalu ye-ettringite ku-HEMC oguquliwe usimende umumo wenduku encane futhi emfushane; Isilinganiso sobude nobubanzi bamakristalu e-ettringite ku-MC oguquliwe usimende slurry sikhulu, esiwumumo wenduku yenaliti. Amakristalu e-ettringite kumaslurry kasimende ajwayelekile ane-aspect ratio phakathi kwalokhu okubili.

(3) Imiphumela ehlukene yama-cellulose ether amabili ku-morphology ye-ettringite ibangelwa ngokuyinhloko umehluko wesisindo samangqamuzana.