Umthelela we-cellulose ether ekushiseni kwe-hydration kasimende ohlukile ne-ore eyodwa

imiphumela ye-cellulose ether ekushiseni kwe-hydration kasimende wase-Portland, usimende we-sulfoaluminate, i-tricalcium silicate ne-tricalcium aluminate ku-72h yaqhathaniswa nokuhlolwa kwe-calorimetry ye-isothermal. Imiphumela ibonisa ukuthi i-cellulose ether inganciphisa kakhulu izinga lokukhishwa kwamanzi kanye nokushisa kwe-Portland Cement kanye ne-tricalcium silicate, futhi umphumela wokuncipha ku-hydration kanye nezinga lokukhishwa kokushisa kwe-tricalcium silicate kubaluleke kakhulu. Umphumela we-cellulose ether ekwehliseni izinga lokukhishwa kokushisa kwe-hydration kasimende we-sulfoaluminate ubuthakathaka kakhulu, kodwa unomphumela obuthakathaka ekuthuthukiseni izinga lokukhishwa kokushisa kwe-hydration ye-tricalcium aluminate. I-Cellulose ether izokhangiswa ngeminye imikhiqizo ye-hydration, ngaleyo ndlela ibambezele ukufakwa kwekristalu kwemikhiqizo ye-hydration, bese ithinta izinga lokukhishwa kokushisa kwe-hydration likasimende ne-ore eyodwa.

Amagama angukhiye:i-cellulose ether; Usimende; Insimbi eyodwa; Ukushisa kwe-hydration; i-adsorption

1. Isingeniso

I-Cellulose ether iyi-ejenti ebalulekile yokuqina kanye ne-ejenti egcina amanzi odakeni olomile oluxubile, ukhonkolo ozihlanganisayo kanye nezinye izinto ezintsha ezenziwe usimende. Kodwa-ke, i-cellulose ether izophinde ibambezele ukugeleza kukasimende, okusiza ukuthuthukisa isikhathi sokusebenza sezinto ezisekelwe kusimende, ukuthuthukisa ukungaguquguquki kodaka kanye nokulahlekelwa isikhathi sokuwohloka kukakhonkolo, kodwa futhi kungase kubambezele ukuqhubeka kokwakhiwa. Ikakhulukazi, kuzoba nemiphumela emibi odakeni nokhonkolo olusetshenziswa ezimweni eziphansi zokushisa kwemvelo. Ngakho-ke, kubaluleke kakhulu ukuqonda umthetho we-cellulose ether ku-cement hydration kinetics.

I-OU kanye ne-Pourchez bahlola ngokuhlelekile imiphumela yemingcele yamangqamuzana njengesisindo sengqamuzana se-cellulose ether, uhlobo lokuthatha indawo noma izinga lokushintsha kusimende hydration kinetics, futhi bafinyelela iziphetho eziningi ezibalulekile: Ikhono le-hydroxyethyl cellulose ether (HEC) ukubambezela ukugeleza kwamanzi usimende uvame ukuba namandla kunalowo we-methyl cellulose ether (HPMC), i-hydroxymethyl ethyl cellulose ether (HEMC) ne-methyl cellulose ether (MC). Ku-ether ye-cellulose equkethe i-methyl, ukwehla kokuqukethwe kwe-methyl, amandla anamandla okubambezela ukugeleza kukasimende; Ukuncipha kwesisindo samangqamuzana e-cellulose ether, amandla okubambezela ukugeleza kukasimende anamandla. Lezi ziphetho zinikeza isisekelo sesayensi sokukhetha i-cellulose ether ngendlela efanele.

Ezingxenyeni ezihlukene zikasimende, umthelela we-cellulose ether ku-cement hydration kinetics uyinkinga ethintekayo kakhulu ekusetshenzisweni kobunjiniyela. Nokho, alukho ucwaningo ngalesi sici. Kuleli phepha, ithonya le-cellulose ether ku-hydration kinetics kasimende we-Portland ojwayelekile, i-C3S(i-tricalcium silicate), i-C3A(i-tricalcium aluminate) kanye nosimende we-sulfoaluminate (SAC) yahlolisiswa ngokuhlolwa kwe-calorimetry ye-isothermal, ukuze kuqondwe kabanzi ukuxhumana indlela yangaphakathi phakathi kwe-cellulose ether kanye nemikhiqizo ye-cement hydration. Ihlinzeka ngesisekelo esengeziwe sesayensi sokusetshenziswa okuphusile kwe-cellulose ether ezintweni ezisekelwe kusimende futhi ihlinzeka ngesisekelo socwaningo sokusebenzelana phakathi kwezinye izixube nemikhiqizo ye-cement hydration.

2. Isivivinyo

2.1 Izinto ezingavuthiwe

(1) usimende ojwayelekile wasePortland (P·0). Ikhiqizwe yi-Wuhan Huaxin Cement Co., LTD., imininingwane ithi P· 042.5 (GB 175-2007), inqunywa i-wavelength dispersion-type X-ray fluorescence spectrometer (AXIOS advanced, PANalytical Co., LTD.). Ngokokuhlaziywa kwesoftware ye-JADE 5.0, ngaphezu kwamaminerali kasimende e-C3S, C2s, C3A, C4AF kanye negypsum, izinto zokusetshenziswa zikasimende nazo zihlanganisa i-calcium carbonate.

(2) usimende we-sulfoaluminate (SAC). Usimende oqinile we-sulfoaluminate okhiqizwa yi-Zhengzhou Wang Lou Cement Industry Co., Ltd. uyi-R.Star 42.5 (GB 20472-2006). Amaqembu ayo ayinhloko yi-calcium sulfoaluminate ne-dicalcium silicate.

(3) i-tricalcium silicate (C3S). Cindezela okuthi Ca(OH)2, SiO2, Co2O3 kanye ne-H2O ngo-3:1:0.08: Isilinganiso sesisindo esingu-10 sixutshwe ngokulinganayo futhi sacindezelwa ngaphansi kwengcindezi engapheli engu-60MPa ukuze kwenziwe i-cylindrical green billet. I-billet yabalwa ku-1400 ℃ amahora angu-1.5 ~ 2 esithandweni sikagesi se-silicon-molybdenum esishisayo, bese ithuthelwa kuhhavini we-microwave ukuze kuqhutshekwe nokushisisa i-microwave imizuzu engu-40. Ngemva kokukhipha i-billet, yapholiswa kungazelelwe futhi yaphuka ngokuphindaphindiwe futhi yabalwa kuze kube yilapho okuqukethwe kwe-CaO yamahhala emkhiqizweni ophelile kwaba ngaphansi kuka-1.0%.

(4) i-tricalcium aluminate (c3A). I-CaO ne-A12O3 zixutshwe ngokulinganayo, zabalwa ku-1450℃ amahora angu-4 esithandweni sikagesi se-silicon-molybdenum, zagaywa zaba yimpushana, futhi zabalwa ngokuphindaphindiwe kuze kube yilapho okuqukethwe kwe-CaO yamahhala kuba ngaphansi kuka-1.0%, kanye neziqongo ze-C12A7 ne-CA indiva.

(5) i-cellulose ether. Umsebenzi wangaphambili uqhathanise imiphumela yezinhlobo ezingu-16 zama-cellulose ether ku-hydration kanye nezinga lokukhishwa kokushisa likasimende ojwayelekile wase-Portland, futhi wathola ukuthi izinhlobo ezahlukene zama-cellulose ethers zinomehluko omkhulu emthethweni we-hydration kanye nokukhishwa kokushisa kukasimende, futhi wahlaziya indlela yangaphakathi. walomehluko omkhulu. Ngokwemiphumela yocwaningo lwangaphambilini, izinhlobo ezintathu ze-cellulose ether ezinomphumela osobala wokuncipha kusimende ojwayelekile wase-Portland zakhethwa. Lokhu kufaka i-hydroxyethyl cellulose ether (HEC), i-hydroxypropyl methyl cellulose ether (HPMC), kanye ne-hydroxyethyl methyl cellulose ether (HEMC). I-viscosity ye-cellulose ether ikalwa nge-viscometer ejikelezayo ene-test concentration engu-2%, izinga lokushisa elingu-20℃ kanye nesivinini sokuzungeza esingu-12 r/min. I-viscosity ye-cellulose ether ikalwa nge-viscometer ejikelezayo ene-test concentration engu-2%, izinga lokushisa elingu-20℃ kanye nesivinini sokuzungeza esingu-12 r/min. Idigri ye-molar esikhundleni se-cellulose ether inikezwa umenzi.

(6) Amanzi. Sebenzisa amanzi acwecwe esibili.

2.2 Indlela yokuhlola

Ukushisa kwe-hydration. I-TAM Air 8-channel isothermal calorimeter ekhiqizwe yi-TA Instrument Company yamukelwa. Zonke izinto zokusetshenziswa zagcinwa izinga lokushisa elingaguquki ukuze kuhlolwe izinga lokushisa (elifana nokuthi (20± 0.5)℃) ngaphambi kokuhlolwa. Okokuqala, i-3 g usimende kanye ne-18 mg cellulose ether powder yengezwe ku-calorimeter (isilinganiso sobuningi be-cellulose ether kuya ezintweni ze-cemellative kwaba ngu-0.6%). Ngemuva kokuxuba okugcwele, amanzi axubile (amanzi acwecwe okwesibili) ayengezwa ngokwesilinganiso esicacisiwe samanzi-samente futhi axutshwe ngokulinganayo. Khona-ke, yafakwa ngokushesha ku-calorimeter ukuze ihlolwe. Isilinganiso sokuhlanganisa amanzi se-c3A ngu-1.1, futhi isilinganiso se-water-binder sezinye izinto ezintathu zikasimende ngu-0.45.

3. Imiphumela kanye nengxoxo

3.1 Imiphumela yokuhlolwa

Imiphumela ye-HEC, HPMC kanye ne-HEMC kuzinga lokukhishwa kokushisa kwe-hydration kanye nezinga lokukhishwa lokushisa elikhulayo likasimende we-Portland ovamile, i-C3S ne-C3A phakathi kwamahora angu-72, kanye nemithelela ye-HEC ngezinga lokukhishwa kokushisa kwe-hydration kanye nezinga lokukhishwa lokushisa elikhulayo likasimende we-sulfoaluminate. phakathi kwamahora angu-72, i-HEC iyi-ether ye-cellulose enomphumela wokubambezeleka oqine kakhulu ekufakweni kwamanzi komunye usimende ne-ore eyodwa. Ukuhlanganisa le miphumela emibili, kungatholakala ukuthi ngoshintsho lokubunjwa kwe-cementitious material, i-cellulose ether inemiphumela ehlukile kuzinga lokukhishwa kokushisa kwe-hydration kanye nokukhululwa kokushisa okukhulayo. I-cellulose ether ekhethiwe inganciphisa kakhulu izinga lokukhishwa kwamanzi nokushisa likasimende ovamile wase-Portland kanye no-C, S, ngokuyinhloko yandise isikhathi sokungeniswa, ibambezele ukubonakala kwe-hydration kanye nenani eliphakeme lokukhululwa kokushisa, phakathi kwayo i-cellulose ether kuya ku-C, S hydration kanye ukubambezeleka kwesilinganiso sokukhishwa kokushisa kusobala kakhulu kune-Portland esivamile hydration kanye nokubambezeleka kwesilinganiso sokukhululwa kokushisa; I-Cellulose ether ingase futhi ibambezele izinga lokukhishwa kokushisa kwe-sulfoaluminate Cement hydration, kodwa ikhono lokulibaziseka libuthakathaka kakhulu, futhi libambezeleka kakhulu ukugeleza kwamanzi ngemva kwamahora angu-2; Ngesilinganiso sokukhishwa kokushisa kwe-C3A hydration, i-cellulose ether inamandla abuthaka wokusheshisa.

3.2 Ukuhlaziya nokuxoxisana

Indlela ye-cellulosic ether ibambezela ukufakwa kukasimende. Silva et al. kucatshangelwe ukuthi i-cellulosic ether yandisa i-viscosity yesisombululo se-pore futhi yavimbela izinga lokunyakaza kwe-ionic, ngaleyo ndlela ibambezeleka ukugeleza kukasimende. Nokho, izincwadi eziningi zikungabaza lokhu kucatshangelwa, njengoba ukuhlola kwabo kuye kwathola ukuthi ama-cellulose ether ane-viscosity ephansi anamandla anamandla okubambezela ukusikwa kukasimende. Eqinisweni, isikhathi sokunyakaza kwe-ion noma ukufuduka sifushane kangangokuthi ngokusobala asiqhathanisi nesikhathi sokulibaziseka kwe-cement hydration. Ukukhangisa phakathi kwe-cellulose ether kanye nemikhiqizo ye-cement hydration kuthathwa njengesizathu sangempela sokubambezeleka kokufakwa kukasimende nge-cellulose ether. I-Cellulose ether ikhangeka kalula ebusweni bemikhiqizo yokukhipha amanzi njenge-calcium hydroxide, ijeli ye-CSH ne-calcium aluminate hydrate, kodwa akulula ukukhangiswa ngesigaba se-ettringite ne-unhydrated, futhi umthamo wokukhangisa we-cellulose ether ku-calcium hydroxide uphakeme lokho kwejeli ye-CSH. Ngakho-ke, emikhiqizweni evamile ye-Portland usimende, i-cellulose ether inokubambezeleka okuqine kakhulu ku-calcium hydroxide, ukubambezeleka okuqine kakhulu kwe-calcium, ukubambezeleka kwesibili kwejeli ye-CSH, nokubambezeleka okubuthakathaka ku-ettringite.

Ucwaningo lwangaphambilini lubonise ukuthi i-adsorption phakathi kwe-polysaccharide engeyona i-ionic kanye nesigaba samaminerali ikakhulukazi ihlanganisa i-hydrogen bonding kanye nokuhlanganiswa kwamakhemikhali, futhi le miphumela emibili yenzeka phakathi kweqembu le-hydroxyl le-polysaccharide kanye ne-hydroxide yensimbi endaweni yamaminerali. Liu et al. iphinde ihlukanise i-adsorption phakathi kwama-polysaccharides nama-hydroxide ensimbi njengokusebenzisana kwe-acid-base, nama-polysaccharides njengama-acids nama-hydroxide ensimbi njengezisekelo. Nge-polysaccharide enikeziwe, i-alkalinity yendawo yezimbiwa inquma amandla okusebenzelana phakathi kwama-polysaccharides namaminerali. Phakathi kwezingxenye ezine ze-gelling ezifundwe kuleli phepha, izakhi eziyinhloko zensimbi noma ezingezona ezensimbi zihlanganisa i-Ca, i-Al kanye ne-Si. Ngokohlelo lomsebenzi wensimbi, i-alkalinity yama-hydroxides awo i-Ca(OH)2>Al(OH3>Si(OH)4. Eqinisweni, isixazululo se-Si(OH)4 sine-acidic futhi asikhangisi i-cellulose ether. okuqukethwe kwe-Ca(OH)2 ebusweni bemikhiqizo ye-cement hydration inquma umthamo we-adsorption wemikhiqizo ye-hydration kanye ne-cellulose ether Ngoba i-calcium hydroxide, i-CSH gel (3CaO · 2SiO2 · 3H20), ettringite (3CaO · Al2O3 · 3CaSO4 · 32H2O) kanye ne-calcium aluminate hydrate (3CaO · Al2O3 · 6H2O) kokuqukethwe kwe-inorganic oxides ye-CaO ingu-100%, 58.33%, 49.56% kanye no-62 .2%. i-aluminate > CSH gel > ettringite, ehambisana nemiphumela ezincwadini.

Imikhiqizo ye-hydration ye-c3S ikakhulukazi ihlanganisa i-Ca(OH) nejeli ye-csH, futhi i-cellulose ether inomphumela wokulibaziseka omuhle kuyo. Ngakho-ke, i-cellulose ether inokubambezeleka okusobala kakhulu ku-C3s hydration. Ngaphandle kwe-c3S, usimende ojwayelekile wase-Portland uhlanganisa nokugeleza kwe-C2s okuhamba kancane, okwenza umphumela wokulibaziseka we-cellulose ether ungabonakali ekuqaleni. Imikhiqizo ye-hydration ye-silicate evamile iphinde ihlanganise i-ettringite, futhi umphumela wokulibaziseka we-cellulose ether mubi. Ngakho-ke, ikhono lokulibaziseka le-cellulose ether kuya ku-c3 linamandla kunalelo likasimende ojwayelekile wase-Portland abonwe ekuhlolweni.

I-C3A izoncibilika futhi ikhiphe amanzi ngokushesha lapho ihlangana namanzi, futhi imikhiqizo ye-hydration ngokuvamile i-C2AH8 ne-c4AH13, futhi ukushisa kwe-hydration kuzokhishwa. Uma isixazululo se-C2AH8 ne-c4AH13 sifinyelela ekugcwalisweni kwesikhala, kuzokwenziwa icrystallization ye-C2AH8 kanye ne-C4AH13 ye-hexagonal sheet hydrate, futhi izinga lokusabela nokushisa kwe-hydration kuzoncishiswa ngesikhathi esifanayo. Ngenxa yokukhanyiswa kwe-cellulose ether ebusweni be-calcium aluminate hydrate (CxAHy), ukuba khona kwe-cellulose ether kuzobambezela ukwenziwa kwekristalu kwe-C2AH8 kanye ne-C4AH13 ye-hexagonal-plate hydrate, okuholela ekwehleni kwezinga lokuphendula kanye nezinga lokukhishwa kokushisa kwe-hydration kunalokho. ye-C3A emsulwa, ekhombisa ukuthi i-cellulose ether inekhono elibuthakathaka lokusheshisa ku-C3A hydration. Kuyaphawuleka ukuthi kulokhu kuhlolwa, i-cellulose ether inamandla asheshayo abuthakathaka ku-hydration ye-c3A ehlanzekile. Kodwa-ke, kusimende ojwayelekile wasePortland, ngoba i-c3A izosabela nge-gypsum ukuze yakhe i-ettringite, ngenxa yethonya lebhalansi ye-ca2+ kusisombululo se-slurry, i-cellulose ether izobambezela ukwakheka kwe-ettringite, ngaleyo ndlela ibambezele ukugeleza kwe-c3A.

Kusukela emiphumeleni ye-HEC, HPMC kanye ne-HEMC ku-hydration kanye nezinga lokukhishwa kokushisa kanye nokukhishwa kokushisa okukhulayo kukasimende we-Portland ovamile, i-C3S ne-C3A phakathi kwamahora angu-72, kanye nemithelela ye-HEC ku-hydration nesilinganiso sokukhishwa kokushisa kanye nokukhishwa kokushisa okukhulayo kwe-sulfoaluminate. usimende ngaphakathi kwe-72 h, kungabonakala ukuthi phakathi kwama-ethers amathathu e-cellulose akhethiwe, Ikhono lokulibaziseka kwe-hydration ye-c3s ne-Portland samente yayinamandla kakhulu ku-HEC, ilandelwa yi-HEMC, futhi ibuthakathaka ku-HPMC. Ngokuqondene ne-C3A, amandla amathathu e-cellulose ethers okusheshisa ukugeleza kwamanzi nawo alandelana okufanayo, okungukuthi, i-HEC iqine kakhulu, i-HEMC ingeyesibili, i-HPMC ibuthakathaka futhi iqine kakhulu. Lokhu kuqinisekisile ngokulinganayo ukuthi i-cellulose ether ibambezele ukwakheka kwemikhiqizo ye-hydration yezinto ezigayilwayo.

Imikhiqizo eyinhloko ye-hydration kasimende we-sulfoaluminate yi-ettringite kanye nejeli ye-Al(OH)3. I-C2S kusimende we-sulfoaluminate izophinde ikhiphe amanzi ngokuhlukana ukuze yakhe ijeli ye-Ca(OH)2 ne-cSH. Ngenxa yokuthi i-adsorption ye-cellulose ether ne-ettringite ingashaywa indiva, futhi ukugeleza kwe-sulfoaluminate kushesha kakhulu, ngakho-ke, esigabeni sokuqala sokufakwa kwamanzi, i-cellulose ether ayinawo umthelela omncane kuzinga lokukhishwa kokushisa kwe-hydration likasimende we-sulfoaluminate. Kodwa ngesikhathi esithile sokugeleza kwamanzi, ngenxa yokuthi ama-c2 azokhipha amanzi ngokwehlukana ukuze akhiqize ijeli ye-Ca(OH)2 ne-CSH, le mikhiqizo emibili yokufakwa kwamanzi izobambezeleka nge-cellulose ether. Ngakho-ke, kwaphawulwa ukuthi i-cellulose ether ibambezele ukugeleza kukasimende we-sulfoaluminate ngemva kwamahora angu-2.

4. Isiphetho

Kuleli phepha, ngokuhlolwa kwe-calorimetry ye-isothermal, umthetho wethonya kanye nendlela yokwakheka kwe-cellulose ether ekushiseni kwe-hydration kasimende we-Portland ojwayelekile, ama-c3s, i-c3A, usimende we-sulfoaluminate nezinye izingxenye ezihlukene kanye ne-ore eyodwa ku-72 h yaqhathaniswa. Iziphetho eziyinhloko yilezi:

(1) I-cellulose ether inganciphisa ngokuphawulekayo izinga lokukhishwa kokushisa kwe-hydration likasimende we-Portland ojwayelekile kanye ne-tricalcium silicate, futhi umphumela wokunciphisa izinga lokukhishwa kokushisa kwe-hydration ye-tricalcium silicate ubaluleke kakhulu; Umthelela we-cellulose ether ekwehliseni izinga lokukhishwa kokushisa kukasimende we-sulfoaluminate ubuthakathaka kakhulu, kodwa unomphumela obuthakathaka ekuthuthukiseni izinga lokukhishwa kokushisa kwe-tricalcium aluminate.

(2) i-cellulose ether izokhangiswa ngeminye imikhiqizo ye-hydration, ngaleyo ndlela ibambezele ukwakhiwa kwe-crystallization yemikhiqizo ye-hydration, kuthinte izinga lokukhishwa kokushisa kwe-cement hydration. Uhlobo nenani lemikhiqizo ye-hydration ihlukile ezingxenyeni ezihlukene ze-ore ye-cement bill, ngakho-ke umphumela we-cellulose ether ekushiseni kwawo kwe-hydration akufani.