I-ether ye-cellulose kwi-morphology ye-ettringite yokuqala

Iziphumo ze-hydroxyethyl methyl cellulose ether kunye ne-methyl cellulose ether kwi-morphology ye-ettringite kwi-slurry yokuqala yesamente zaphononongwa ngokuskena i-electron microscopy (SEM). Iziphumo zibonisa ukuba umlinganiselo wobude bobude beekristale ze-ettringite kwi-hydroxyethyl methyl cellulose ether eguquliweyo ludaka luncinci kunoludaka oluqhelekileyo, kwaye i-morphology ye-ettringite crystals ifana nentonga emfutshane. Umlinganiselo wobude bobude beekristale ze-ettringite kwi-methyl cellulose ether eguquliweyo ludaka olukhulu kunoludaka oluqhelekileyo, kwaye i-morphology ye-ettringite crystals yinaliti-yenaliti. Iikristale ze-ettringite kwi-slurries yesamente eqhelekileyo inomlinganiselo wembonakalo kwindawo ethile phakathi. Ngolu phando lovavanyo lungentla, kucacile ngakumbi ukuba umahluko we-molecular weight yeentlobo ezimbini ze-cellulose ether yeyona nto ibalulekileyo echaphazela i-morphology ye-ettringite.

Amagama angundoqo:i-ettringite Umlinganiselo wobude bobubanzi; iMethyl cellulose ether; I-Hydroxyethyl methyl cellulose ether; imorphology

I-Ettringite, njengemveliso ye-hydration eyandisiweyo kancinane, inempembelelo ebalulekileyo ekusebenzeni kwekhonkrithi yesamente, kwaye ibisoloko iyindawo yophando yezinto ezisekelwe kwi-samente. I-Ettringite luhlobo lwe-trisulfide yohlobo lwe-calcium aluminate hydrate, ifomula yayo yekhemikhali yi [Ca3Al (OH) 6 · 12H2O]2 · (SO4)3 · 2H2O, okanye ingabhalwa njenge-3CaO · Al2O3 · 3CaSO4 · 32H2O, ihlala ifinyezwa njenge-AFt. . Kwinkqubo yesamente yasePortland, i-ettringite yenziwa ikakhulu kukusabela kwegypsum kunye neeminerali ze-aluminate okanye i-ferric aluminate, edlala indima yokulibaziseka kwe-hydration kunye namandla okuqala e-samente. Ukuqulunqwa kunye ne-morphology ye-ettringite ichaphazeleka kwizinto ezininzi ezifana nobushushu, ixabiso le-pH kunye nokugxininiswa kwe-ion. Kwangoko ngo-1976, uMetha et al. isebenzise i-electron microscopy yokuskena ukufunda iimpawu ze-morphological ze-AFt, kwaye yafumanisa ukuba i-morphology yemveliso ye-hydration eyandiswe kancinane yayahluke kancinane xa isithuba sokukhula sasisikhulu ngokwaneleyo kwaye xa isithuba sasilinganiselwe. Eyangaphambili ubukhulu becala yayizingqukuva ezibhityileyo ezimile okwenaliti, ngelixa eyokugqibela ubukhulu becala yayiyiprism emifutshane emile okwentonga. Uphando lukaYang Wenyan lwafumanisa ukuba iifom ze-AFt zazahlukile ngeendawo ezahlukeneyo zokunyanga. Iindawo ezimanzi ziya kulibazisa ukuveliswa kwe-AFt kwikhonkrithi eyongeziweyo kwaye yandise amathuba okudumba kwekhonkrithi kunye nokuqhekeka. Imimandla eyahlukeneyo ayichaphazeli kuphela ukubunjwa kunye ne-microstructure ye-AFt, kodwa kunye nokuzinza kwayo umthamo. UChen Huxing et al. ifumene ukuba ukuzinza kwexesha elide le-AFt lehlile ngokunyuka komxholo we-C3A. UClark noMonteiro et al. yafumanisa ukuba ngokunyuka koxinzelelo lwendalo, i-AFt crystal structure yatshintsha ukusuka kwi-order ukuya kwi-disorder. I-Balonis kunye ne-Glasser zihlolisise utshintsho loxinaniso lwe-AFm kunye ne-AFt. URenaudin et al. wafunda utshintsho lwesakhiwo se-AFt ngaphambi nangemva kokuntywiliselwa kwisisombululo kunye neeparamitha zesakhiwo se-AFt kwi-Raman spectrum. Kunther et al. wafunda umphumo wokusebenzisana phakathi kwe-CSH gel calcium-silicon ratio kunye ne-sulfate ion kwi-AFt crystallization pressure yi-NMR. Ngelo xesha, ngokusekelwe kwisicelo se-AFt kwizinto ezisekelwe kwisamente, i-Wenk et al. wafunda i-AFt crystal orientation yecandelo lekhonkrithi ngokusebenzisa i-synchrotron enzima ye-radiation X-ray diffraction finishing technology. Ukuqulunqwa kwe-AFt kwi-samente exutywe kunye ne-hotspot yophando ye-ettringite yaphononongwa. Ngokusekwe kwi-ettringite reaction yokulibaziseka, abanye abaphengululi baye baqhuba uphando oluninzi malunga nonobangela wesigaba se-AFt.

Ukwandiswa komthamo obangelwa ukubunjwa kwe-ettringite ngamanye amaxesha kuthandeka, kwaye kunokusebenza "njengokwandiswa" okufana ne-agent ye-magnesium oxide yokwandisa ukugcina umthamo wokuzinza kwezinto ezisekelwe kwi-samente. Ukongezwa kwe-emulsion ye-polymer kunye ne-emulsion powder edispersible iguqula iipropati ze-macroscopic zezinto ezisekelwe kwi-samente ngenxa yemiphumo yazo ebalulekileyo kwi-microstructure yezinto ezisekelwe kwi-samente. Nangona kunjalo, ngokungafaniyo nomgubo we-emulsion owenziweyo ophucula ubukhulu becala ipropathi edibeneyo yodaka oluqinileyo, i-polymer cellulose ether enyibilikayo yamanzi (CE) inika udaka olusanda kuhlanganiswa ukugcinwa kwamanzi kunye nokuqina, ngaloo ndlela kuphuculwe ukusebenza komsebenzi. I-CE engeyiyo i-ionic isetyenziswa ngokuqhelekileyo, kuquka i-methyl cellulose (MC), i-hydroxyethyl cellulose (HEC), i-hydroxypropyl methyl cellulose (HPMC),i-hydroxyethyl methyl cellulose (HEMC), njl., kunye ne-CE idlala indima kwi-mortar esanda kuxutywa kodwa ichaphazela inkqubo ye-hydration ye-cement slurry. Uphononongo lubonise ukuba i-HEMC itshintsha isixa se-AFt esiveliswe njengemveliso ye-hydration. Nangona kunjalo, akukho zifundo eziye zathelekisa ngokucwangcisiweyo umphumo we-CE kwi-morphology ye-microscopic ye-AFt, ngoko eli phepha liphonononga umahluko wempembelelo ye-HEMC kunye ne-MC kwi-microscopic morphology ye-ettringham ekuqaleni (i-1-day) ye-cement slurry ngokuhlalutya umfanekiso kunye uthelekiso.

1. Linge

1.1 IiMathiriyeli ezikrwada

I-P · II 52.5R i-samente yasePortland eveliswe yi-Anhui Conch Cement Co., LTD yakhethwa njenge-samente kuvavanyo. I-ethers ezimbini ze-cellulose ziyi-hydroxyethyl methylcellulose (HEMC) kunye ne-methylcellulose (i-methylcellulose, i-Shanghai Sinopath Group) ngokulandelanayo. MC); Amanzi axutywayo ngamanzi epompo.

1.2 Iindlela zovavanyo

Umlinganiselo wamanzi we-samente yesampula yokunamathisela i-samente yayingu-0.4 (umlinganiselo wobuninzi bamanzi ukuya kwi-samente), kunye nomxholo we-cellulose ether wawuyi-1% yobunzima besamente. Ukulungiswa komzekelo wenziwa ngokwe-GB1346-2011 "Indlela yoVavanyo yokuSetyenziswa kwamanzi, ukuSeta ixesha kunye nokuzinza koMgangatho we-Cement Consistency". Emva kokwenza lo mzekelo, ifilimu yeplastiki yagqunywa kumphezulu wokungunda ukuthintela ukuvela kwamanzi angaphezulu komphunga kunye necarbonization, kwaye lo mzekelo wabekwa kwigumbi lokunyanga elinobushushu obuyi-(20±2)℃ kunye nokufuma okunxulumene ne (60±5) %. Emva komhla we-1, isikhunta sasuswa, kwaye i-specimen yaphulwa, emva koko isampuli encinci ithathwe phakathi kwaye ifakwe kwi-ethanol e-anhydrous ukuphelisa i-hydration, kwaye isampuli yathathwa kwaye yomiswa ngaphambi kokuvavanya. Iisampulu ezomisiweyo zancanyathiselwa kwitheyibhile yesampulu kunye nencamatheliswayo emacala omabini, kwaye umaleko wefilimu yegolide watshizwa kumphezulu ngeCressington 108auto automatic ion sputtering isixhobo. I-sputtering current yayiyi-20 mA kwaye ixesha lokutshiza laliyi-60 s. I-FEI QUANTAFEG 650 yokusingqongileyo Ukuskena i-electron iMicroscope (ESEM) yasetyenziselwa ukujonga iimpawu ze-morphological ze-AFt kwicandelo lesampulu. Imowudi ye-electron yesibini ye-vacuum ephezulu yayisetyenziselwa ukujonga i-AFT. I-voltage ye-acceleration yayiyi-15 kV, ububanzi bendawo ye-beam yayiyi-3.0 nm, kwaye umgama wokusebenza ulawulwa malunga ne-10 mm.

2. Iziphumo kunye nengxoxo

Imifanekiso ye-SEM ye-ettringite kwi-HEMC-modified slurry ye-cement eqinile ibonise ukuba ukukhula kwe-orientation ye-Ca (OH) 2 (CH) yayicacile, kwaye i-AFt ibonise ukuqokelela okungaqhelekanga kwe-AFt emfutshane efana nentonga, kunye ne-AFT emfutshane efana ne-AFT. kunye ne-HEMC isakhiwo se-membrane. UZhang Dongfang et al. kwakhona kufunyenwe intonga emfutshane efana ne-AFt xa uqwalasela utshintsho lwe-microstructure ye-HEMC eguqulelwe ngodaka lwesamente nge-ESEM. Bakholelwa ukuba i-samente slurry eqhelekileyo iphendule ngokukhawuleza emva kokudibana namanzi, ngoko ke i-crystal ye-AFt yayincinci, kwaye ukwandiswa kwexesha le-hydration kwakhokelela ekunyukeni okuqhubekayo komlinganiselo wobude bobude. Nangona kunjalo, i-HEMC yandisa i-viscosity yesisombululo, yanciphisa izinga lokubopha i-ion kwisisombululo kwaye yalibazisa ukufika kwamanzi phezu kwamaqhekeza e-clinker, ngoko ke umlinganiselo wobude bobubanzi be-AFt unyuke kwindlela ebuthathaka kunye neempawu zayo ze-morphological zibonise. imilo emifutshane efana nentonga. Xa kuthelekiswa ne-AFt kwi-slurry ye-cement eqhelekileyo yeminyaka efanayo, le ngcamango iqinisekisiwe ngokuyinxenye, kodwa ayisebenzi ukucacisa utshintsho lwe-morphological ye-AFt kwi-MC modified cement slurry. Imifanekiso ye-SEM ye-etridite kwi-1 yosuku olulukhuni lwe-MC oluguquliweyo lwe-cement luphinde lwabonisa ukukhula okujoliswe kuko kwe-Ca (OH) ene-2, ezinye iindawo ze-AFt nazo zagqunywa ngesakhiwo sefilimu ye-MC, kwaye i-AFt ibonise iimpawu ze-morphological zokukhula kweqela. Nangona kunjalo, ngokuthelekisa, i-crystal ye-AFt kwi-MC eguqulelwe kwi-cement slurry inomlinganiselo omkhulu wobude bobude kunye ne-morphology ebhityileyo, ebonisa i-acicular morphology.

Bobabini i-HEMC kunye ne-MC yalibazisa inkqubo ye-hydration yokuqala ye-samente kwaye yandisa i-viscosity yesisombululo, kodwa ukungafani kweempawu ze-AFt ze-morphological ezibangelwa kubo kwakusebalulekile. Ezi zinto zingasentla zinokucaciswa ngakumbi kumbono wesakhiwo semolekyuli ye-cellulose ether kunye ne-AFt crystal structure. URenaudin et al. ifakwe i-AFt edibeneyo kwisisombululo esilungisiweyo se-alkali ukufumana "i-AFt emanzi", kwaye isuswe ngokuyinxenye kwaye yomise kumphezulu wesisombululo se-CaCl2 esihluthayo (35% ukufuma okuhambelanayo) ukufumana "i-AFt eyomileyo". Emva kokufundwa kokulungiswa kwesakhiwo nguRaman spectroscopy kunye ne-X-ray powder diffraction, kwafunyaniswa ukuba akukho mahluko phakathi kwezakhiwo ezibini, kuphela isalathiso sokubunjwa kwekristale yeeseli ezitshintshileyo kwinkqubo yokomisa, oko kukuthi, kwinkqubo yokusingqongileyo. utshintsho ukusuka "kumanzi" ukuya "komileyo", iikristale ze-AFt zenza iiseli kwicala eliqhelekileyo lokunyuka ngokuthe ngcembe. Iikristale ze-AFt ecaleni kolwalathiso lwe-c oluqhelekileyo lwaba luncinci kwaye luncinci. Eyona yunithi isisiseko sesithuba se-three-dimensional yenziwe ngumgca oqhelekileyo, umgca we-b oqhelekileyo kunye nomgca oqhelekileyo we-perpendicular omnye komnye. Kwimeko apho i-b normals ilungisiwe, iikristale ze-AFt zadityaniswa kunye neendlela eziqhelekileyo, ezikhokelela ekubeni i-cell cross cross section eyandisiweyo kwi-plane ye-ab normals. Ngaloo ndlela, ukuba i-HEMC "igcina" amanzi amaninzi kune-MC, indawo "eyomileyo" ingenzeka kwindawo yendawo, ikhuthaze ukuhlanganiswa kwecala kunye nokukhula kweekristale ze-AFt. Patural et al. yafumanisa ukuba kwi-CE ngokwayo, iqondo eliphezulu le-polymerization (okanye ubukhulu be-molecular weight), i-viscosity enkulu ye-CE kwaye ingcono ukusebenza kokugcinwa kwamanzi. I-molecular structure ye-HEMCs kunye ne-MCS isekela le ngcamango, kunye neqela le-hydroxyethyl elinobunzima obukhulu be-molecular kuneqela le-hydrogen.

Ngokuqhelekileyo, i-crystals ye-AFt iya kwenza kwaye iqhube kuphela xa i-ion efanelekileyo ifikelela kwi-saturation ethile kwinkqubo yesisombululo. Ngoko ke, izinto ezifana nokugxininiswa kwe-ion, ubushushu, ixabiso le-pH kunye nesithuba sokubunjwa kwisisombululo sokuphendula sinokuchaphazela kakhulu i-morphology ye-crystals ye-AFt, kunye nokutshintsha kweemeko zokwenziwa kwezinto ezenziweyo kunokutshintsha i-morphology ye-crystals ye-AFt. Ngoko ke, umlinganiselo weekristale ze-AFt kwi-slurry eqhelekileyo yesamente phakathi kwezi zibini unokubangelwa yinto enye yokusetyenziswa kwamanzi kwi-hydration yokuqala ye-samente. Nangona kunjalo, umahluko kwi-AFt crystal morphology ebangelwa yi-HEMC kunye ne-MC kufuneka ibe ngenxa yendlela yabo ekhethekileyo yokugcina amanzi. I-Hemcs kunye ne-MCS zenza "i-loop evaliweyo" yezothutho zamanzi phakathi kwe-microzone yodaka lwesamente entsha, evumela "ixesha elifutshane" apho amanzi "kulula ukungena kwaye kunzima ukuphuma." Nangona kunjalo, ngeli xesha, indawo yesigaba solwelo ngaphakathi nakufuphi ne-microzone nayo iyatshintshwa. Izinto ezifana ne-ion concentration, i-pH, njl., Ukutshintsha kwendawo yokukhula kubonakaliswa ngakumbi kwiimpawu ze-morphological ze-crystals ze-AFt. Le "loop evaliweyo" yokuthuthwa kwamanzi ifana nendlela yokusebenza echazwe nguPourchez et al. I-HPMC idlala indima yokugcina amanzi.

3. Isiphelo

(1) Ukongezwa kwe-hydroxyethyl methyl cellulose ether (HEMC) kunye ne-methyl cellulose ether (MC) inokutshintsha kakhulu i-morphology ye-ettringite ekuqaleni (usuku lwe-1) i-sement slurry eqhelekileyo.

(2) Ubude kunye nobubanzi bekristale ye-ettringite kwi-HEMC eguqulelwe kwi-samente slurry incinci kwaye imfutshane intonga; Ubude kunye nedayamitha ratio yeekristale ettringite kwi-MC modified ludaka lwesamente mkhulu, nto leyo imilo inaliti-intonga. Iikristale ze-ettringite kwi-slurries yesamente eqhelekileyo inomlinganiselo wecala phakathi kwezi zimbini.

(3) Iimpembelelo ezahlukeneyo ze-cellulose ethers ezimbini kwi-morphology ye-ettringite ziyimfuneko ngenxa yokwahlukana kwesisindo se-molecular.