Impembelelo ye-cellulose ether kubushushu be-hydration yesamente eyahlukileyo kunye nentsimbi enye

iziphumo ze-cellulose ether kubushushu be-hydration ye-samente yasePortland, i-samente ye-sulfoaluminate, i-tricalcium silicate kunye ne-tricalcium aluminate kwi-72h yafaniswa novavanyo lwe-calorimetry ye-isothermal. Iziphumo zibonisa ukuba i-cellulose ether inokunciphisa kakhulu i-hydration kunye neqondo lokukhululwa kobushushu be-Portland sement kunye ne-tricalcium silicate, kunye nefuthe lokunciphisa i-hydration kunye neqondo lokukhululwa kobushushu be-tricalcium silicate kubaluleke kakhulu. Impembelelo ye-cellulose ether ekunciphiseni izinga lokukhululwa kobushushu be-hydration ye-sulfoaluminate samente ibuthathaka kakhulu, kodwa inempembelelo ebuthathaka ekuphuculeni izinga lokukhululwa kobushushu be-hydration ye-tricalcium aluminate. I-ether ye-cellulose iya kubhengezwa ngezinye iimveliso ze-hydration, ngaloo ndlela ilibazisa i-crystallization yeemveliso ze-hydration, kwaye emva koko ichaphazele izinga lokukhutshwa kobushushu be-hydration yesamente kunye ne-ore enye.

Amagama angundoqo:i-cellulose ether; Isamente; Intsimbi enye; Ubushushu be-hydration; i-adsorption

1. Intshayelelo

I-ether yeCellulose yinto ebalulekileyo yokuqina kunye ne-arhente yokugcina amanzi kudaka olomileyo oluxutyiweyo, ikhonkrithi ezenzelayo kunye nezinye izinto ezintsha ezisekwe kwisamente. Nangona kunjalo, i-ether ye-cellulose iya kulibazisa ukuhanjiswa kwe-samente, ekulungele ukuphucula ixesha lokusebenza kwezinto ezisekelwe kwi-samente, ukuphucula ukungaguquki kodaka kunye nokulahleka kwexesha lokudilika kwekhonkrithi, kodwa kwakhona kunokulibazisa inkqubela phambili yokwakha. Ngokukodwa, iya kuba nemiphumo emibi kwidaka kunye nekhonkrithi esetyenziswa kwiimeko eziphantsi zobushushu obuphantsi. Ngoko ke, kubaluleke kakhulu ukuqonda umthetho we-cellulose ether kwi-cement hydration kinetics.

I-OU kunye ne-Pourchez bafunde ngokucwangcisiweyo imiphumo yeeparamitha zemolekyuli ezifana nobunzima bemolekyuli ye-cellulose ether, uhlobo lwe-substituent okanye i-degree of substitution kwi-cement hydration kinetics, kwaye bafikelela kwizigqibo ezininzi ezibalulekileyo: Ukukwazi kwe-hydroxyethyl cellulose ether (HEC) ukulibazisa i-hydration isamente idla ngokuba namandla kune-methyl cellulose ether (HPMC), i-hydroxymethyl ethyl cellulose ether (HEMC) kunye ne-methyl cellulose ether (MC). Kwi-cellulose ether equkethe i-methyl, i-methyl ephantsi yomxholo, inamandla amandla okulibazisa i-hydration ye-cement; Okukhona kusezantsi ubunzima bemolekyuli ye-cellulose ether, kokukhona komelela ukukwazi ukulibazisa ukuhanjiswa kwesamente. Ezi zigqibo zibonelela ngesiseko senzululwazi sokukhetha i-cellulose ether ngokuchanekileyo.

Kumacandelo ahlukeneyo esamente, impembelelo ye-cellulose ether kwi-cement hydration kinetics nayo yingxaki echaphazelekayo kwizicelo zobunjineli. Nangona kunjalo, akukho phando malunga nalo mba. Kweli phepha, impembelelo ye-cellulose ether kwi-hydration kinetics ye-samente ye-Portland eqhelekileyo, i-C3S (i-tricalcium silicate), i-C3A (i-tricalcium aluminate) kunye ne-samente ye-sulfoaluminate (SAC) yafundwa ngovavanyo lwe-calorimetry ye-isothermal, ukuze uqonde ngakumbi ukusebenzisana kunye indlela yangaphakathi phakathi kwe-cellulose ether kunye neemveliso ze-samente ze-hydration. Ibonelela ngesiseko senzululwazi esingaphezulu sokusetyenziswa okunengqiqo kwe-cellulose ether kwizinto ezisekwe kwisamente kwaye ikwabonelela ngesiseko sophando kwintsebenziswano phakathi kwezinye izinto ezidityanisiweyo kunye neemveliso zesamente zokugalela amanzi.

2. Uvavanyo

2.1 IiMathiriyeli ekrwada

(1) isamente yePortland eqhelekileyo (P · 0). Yenziwe nguWuhan Huaxin Cement Co., LTD., inkcazo yiP · 042.5 (GB 175-2007), igqitywe yi-wavelength dispersion-type X-ray fluorescence spectrometer (AXIOS advanced, PANalytical Co., LTD.). Ngokohlalutyo lwe-software ye-JADE 5.0, ngaphezu kweeminerali ze-cement clinker C3S, i-C2s, i-C3A, i-C4AF kunye ne-gypsum, izinto eziphathekayo ze-samente nazo ziquka i-calcium carbonate.

(2) i-sulfoaluminate cement (SAC). I-samente ye-sulfoaluminate ekhawulezayo ekhutshwe yi-Zhengzhou Wang Lou Cement Industry Co., Ltd. yi-R.Star 42.5 (GB 20472-2006). Amaqela ayo aphambili yi-calcium sulfoaluminate kunye ne-dicalcium silicate.

(3) i-tricalcium silicate (C3S). Cinezela i-Ca (OH) 2, i-SiO2, i-Co2O3 kunye ne-H2O kwi-3: 1: 0.08: Umlinganiselo wobunzima be-10 wawuxutywe ngokulinganayo kwaye ucinezele phantsi koxinzelelo oluqhubekayo lwe-60MPa ukwenza i-cylindrical green billet. Ibhilethi yabalwa kwi-1400℃ ye-1.5 ~ 2 h kwi-silicon-molybdenum intonga yesithando sombane esinobushushu obuphezulu, kwaye emva koko yafuduselwa kwi-oven ye-microwave ukufudumeza ngakumbi i-microwave ngama-40min. Emva kokukhupha i-billet, yaphola ngokukhawuleza kwaye yaphulwa ngokuphindaphindiweyo kwaye yabalwa kwaze kwaba yilapho umxholo we-CaO yamahhala kwimveliso egqityiweyo yayingaphantsi kwe-1.0%

(4) i-tricalcium aluminate (c3A). I-CaO kunye ne-A12O3 yayixutywe ngokulinganayo, i-calcined kwi-1450 ℃ ye-4 h kwisithando sombane se-silicon-molybdenum, umhlaba ube ngumgubo, kwaye uphindwe ngokuphindaphindiweyo kude kube umxholo we-CaO wamahhala ungaphantsi kwe-1.0%, kunye neencopho ze-C12A7 kunye ne-CA zaye zaba ingahoywa.

(5) i-cellulose ether. Umsebenzi wangaphambili uthelekise iziphumo ze-16 iintlobo ze-ethers ze-cellulose kwi-hydration kunye nesantya sokukhululwa kobushushu besamente ye-Portland eqhelekileyo, kwaye yafumanisa ukuba iintlobo ezahlukeneyo ze-ethers ze-cellulose zinomehluko omkhulu kwi-hydration kunye nomthetho wokukhululwa kobushushu besamente, kwaye uhlalutye indlela yangaphakathi. yalo mahluko ubalulekileyo. Ngokweziphumo zophononongo lwangaphambili, kwakhethwa iintlobo ezintathu ze-cellulose ether ezinempembelelo ebambekayo yokuncipha kwisamente eqhelekileyo yasePortland. Ezi ziquka i-hydroxyethyl cellulose ether (HEC), i-hydroxypropyl methyl cellulose ether (HPMC), kunye ne-hydroxyethyl methyl cellulose ether (HEMC). I-viscosity ye-cellulose ether ilinganiswa ne-viscometer ye-rotary ene-test concentration ye-2%, iqondo lokushisa kwe-20 ℃ kunye nesantya sokujikeleza kwe-12 r / min. I-viscosity ye-cellulose ether ilinganiswa ne-viscometer ye-rotary ene-test concentration ye-2%, iqondo lokushisa kwe-20 ℃ kunye nesantya sokujikeleza kwe-12 r / min. Idigri ye-molar substitution ye-cellulose ether inikezelwa ngumenzi.

(6) Amanzi. Sebenzisa amanzi esibini adibeneyo.

2.2 Indlela yokuvavanya

Ubushushu be-hydration. I-TAM Air 8-channel isothermal calorimeter eveliswe yi-TA Instrument Company yamkelwa. Zonke izinto ezikrwada zagcinwa ubushushu obungaguqukiyo ukuvavanya ubushushu (obunje (20± 0.5)℃) phambi kovavanyo. Okokuqala, i-3 g i-samente kunye ne-18 mg ye-cellulose ether powder yongezwa kwi-calorimeter (i-mass ratio ye-cellulose ether kwi-cemellative material yayingu-0.6%). Emva kokuxuba okugcweleyo, amanzi adibeneyo (amanzi adibeneyo esibini) adityaniswe ngokomlinganiselo ochaziweyo wamanzi-samente kwaye axutywe ngokulinganayo. Emva koko, yafakwa ngokukhawuleza kwikhalorimitha yokuvavanya. I-water-binder ratio ye-c3A yi-1.1, kunye ne-water-binder ratio yezinye izinto ezintathu ze-cementitious yi-0.45.

3. Iziphumo kunye nengxoxo

3.1 Iziphumo zovavanyo

Iziphumo ze-HEC, i-HPMC kunye ne-HEMC kwizinga lokukhutshwa kobushushu be-hydration kunye nezinga lokukhululwa kobushushu obukhulayo be-samente ye-Portland eqhelekileyo, i-C3S kunye ne-C3A ngaphakathi kwe-72 h, kunye nemiphumo ye-HEC kwizinga lokukhutshwa kobushushu be-hydration kunye nesantya sokukhululwa kobushushu besamente ye-sulfoaluminate. ngaphakathi kwe-72 h, i-HEC yi-ether ye-cellulose enefuthe elinamandla lokulibaziseka kwi-hydration yenye i-samente kunye ne-ore enye. Ukudibanisa imiphumo emibini, kunokufunyanwa ukuba ngokuguqulwa kokwakheka kwezinto ze-cementitious, i-cellulose ether ineempembelelo ezahlukeneyo kwizinga lokukhutshwa kobushushu be-hydration kunye nokukhululwa kobushushu obukhulayo. I-ether ye-cellulose ekhethiweyo inokunciphisa ngokuphawulekayo i-hydration kunye nesantya sokukhululwa kobushushu be-samente yasePortland eqhelekileyo kunye ne-C, S, ubukhulu becala yandisa ixesha lokungeniswa, ukulibazisa ukubonakala kwe-hydration kunye nencopho yokukhululwa kobushushu, phakathi kwayo i-ether cellulose ukuya ku-C, i-S hydration kunye ukulibaziseka kokukhutshwa kobushushu kubonakala ngakumbi kunesiqhelo sePortland sement hydration kunye nokulibaziseka kokukhutshwa kobushushu; I-ether ye-cellulose inokulibazisa izinga lokukhululwa kobushushu be-sulfoaluminate cement hydration, kodwa amandla okulibazisa abuthathaka kakhulu, kwaye ngokukodwa ukulibazisa ukuhanjiswa emva kwe-2 h; Ngomlinganiselo wokukhutshwa kobushushu be-C3A hydration, i-cellulose ether inamandla okukhawulezisa abuthathaka.

3.2 Uhlalutyo nengxoxo

Indlela yokulibaziseka kwe-ether ye-cellulosic kwi-cement hydration. USilva et al. I-hypothesized ether cellulosic yandisa i-viscosity yesisombululo se-pore kwaye yathintela izinga lokuhamba kwe-ionic, ngaloo ndlela ilibazisa ukuhanjiswa kwesamente. Nangona kunjalo, uncwadi oluninzi luyayithandabuza le ngcinga, njengoko iimvavanyo zabo ziye zafumanisa ukuba ii-cellulose ethers ezine-viscosity ephantsi zinamandla amakhulu okulibazisa ukuhanjiswa kwesamente. Enyanisweni, ixesha lokuhamba kwe-ion okanye ukufuduka lifutshane kangangokuba ngokucacileyo alinakuthelekiswa nexesha lokulibaziseka kwe-cement hydration. I-adsorption phakathi kwe-cellulose ether kunye neemveliso ze-cement hydration zithathwa njengesona sizathu sokulibaziseka kwe-cement hydration nge-cellulose ether. I-cellulose ether ibhengezwa ngokulula kumphezulu weemveliso ze-hydroxide ezifana ne-calcium hydroxide, ijeli ye-CSH kunye ne-calcium aluminate hydrate, kodwa akulula ukuba ibhengezwe ngesigaba se-ettringite kunye ne-unhydrated, kunye nomthamo we-adsorption ye-cellulose ether kwi-calcium hydroxide iphezulu kune leyo yejeli ye-CSH. Ke ngoko, kwiimveliso zesamente zePortland eziqhelekileyo, i-cellulose ether inokulibaziseka okunamandla kwi-calcium hydroxide, ukulibaziseka okunamandla kwi-calcium, ukulibaziseka kwesibini kwijeli ye-CSH, kunye nokulibaziseka okubuthathaka kwi-ettringite.

Uphononongo lwangaphambili lubonise ukuba i-adsorption phakathi kwe-polysaccharide engeyiyo i-ionic kunye nesigaba seminerali ibandakanya ikakhulu i-hydrogen bonding kunye ne-chemical complexation, kwaye ezi ziphumo zimbini zenzeka phakathi kweqela le-hydroxyl ye-polysaccharide kunye ne-hydroxide yensimbi kumphezulu wamaminerali. ULiu et al. Yahlula ngakumbi i-adsorption phakathi kwe-polysaccharides kunye ne-hydroxides yensimbi njenge-acid-base interaction, kunye ne-polysaccharides njenge-acids kunye nee-hydroxides zetsimbi njengeziseko. Kwi-polysaccharide enikeziweyo, i-alkalinity ye-mineral surface inquma amandla okusebenzisana phakathi kwe-polysaccharides kunye neeminerali. Phakathi kwezinto ezine ze-gelling ezifundwe kweli phepha, isinyithi esiphambili okanye i-non-metal elements ziquka i-Ca, i-Al kunye ne-Si. Ngokomyalelo wesinyithi, i-alkalinity ye-hydroxides yabo yi-Ca (OH) 2> Al (OH3> Si (OH) 4. Enyanisweni, isisombululo se-Si (OH) 4 si-acidic kwaye asibhengezi i-cellulose ether. umxholo weCa (OH) 2 kumphezulu weemveliso ze-cement hydration umisela amandla e-adsorption yeemveliso ze-hydration kunye ne-cellulose ether Ngenxa yokuba i-calcium hydroxide, i-CSH gel (3CaO · 2SiO2 · 3H20), ettringite (3CaO · Al2O3 · 3CaSO4 · 32H2O) kunye ne-calcium aluminate hydrate (3CaO · Al2O3 · 6H2O) kumxholo we-inorganic oxides ye-CaO yi-100%, 58.33%, 49.56% kunye ne-62 .2%. aluminate > CSH gel > ettringite, ehambelana neziphumo kuncwadi.

Iimveliso ze-hydration ze-c3S ikakhulu ziquka i-Ca (OH) kunye ne-gel ye-csH, kunye ne-cellulose ether inesiphumo esihle sokulibaziseka kubo. Ngoko ke, i-cellulose ether inokulibaziseka okucacileyo kwi-C3s hydration. Ngaphandle kwe-c3S, isamente yePortland eqhelekileyo ikwabandakanya i-C2s hydration ecothayo, eyenza ukulibaziseka kwe-ether cellulose kungabonakali kwinqanaba lokuqala. Iimveliso ze-hydration ze-silicate eziqhelekileyo zikwabandakanya i-ettringite, kunye nefuthe lokulibaziseka kwe-cellulose ether impofu. Ke ngoko, ukulibaziseka kokukwazi kwe-cellulose ether ukuya kwi-c3s yomelele kunesamente eqhelekileyo yasePortland ebonwe kuvavanyo.

I-C3A iya kuchithwa kwaye ikhuphe ngokukhawuleza xa idibana namanzi, kwaye iimveliso ze-hydration zihlala zi-C2AH8 kunye ne-c4AH13, kwaye ukushisa kwe-hydration kuya kukhutshwa. Xa isisombululo se-C2AH8 kunye ne-c4AH13 sifikelela kwi-saturation, i-crystallization ye-C2AH8 kunye ne-C4AH13 ye-hexagonal sheet hydrate iya kwenziwa, kwaye izinga lokuphendula kunye nokushisa kwe-hydration kuya kuncitshiswa ngexesha elifanayo. Ngenxa yokufakwa kwe-cellulose ether kumphezulu we-calcium aluminate hydrate (CxAHy), ubukho be-cellulose ether buya kulibazisa icrystallization ye-C2AH8 kunye ne-C4AH13 ye-hexagonal-plate hydrate, okukhokelela ekwehleni kwesantya sokuphendula kunye nesantya sokukhulula ubushushu kunoko. ye-C3A ecocekileyo, ebonisa ukuba i-ether ye-cellulose inamandla okukhawulezisa okubuthathaka kwi-C3A hydration. Kuyafaneleka ukuba uqaphele ukuba kolu vavanyo, i-cellulose ether inamandla okukhawuleza obuthathaka kwi-hydration ye-c3A ecocekileyo. Nangona kunjalo, kwi-samente ye-Portland eqhelekileyo, kuba i-c3A iya kusabela nge-gypsum ukuze yenze i-ettringite, ngenxa yempembelelo ye-ca2 + ibhalansi kwisisombululo se-slurry, i-cellulose ether iya kulibazisa ukubunjwa kwe-ettringite, ngaloo ndlela ilibazise i-hydration ye-c3A.

Ukususela kwimiphumo ye-HEC, i-HPMC kunye ne-HEMC kwi-hydration kunye neqondo lokukhululwa kobushushu kunye nokukhululwa kobushushu obukhulayo be-samente ye-Portland eqhelekileyo, i-C3S kunye ne-C3A ngaphakathi kwe-72 h, kunye nemiphumo ye-HEC kwi-hydration kunye neqondo lokukhululwa kobushushu kunye nokukhululwa kobushushu obukhulayo be-sulfoaluminate. i-samente ngaphakathi kwe-72 h, kunokubonwa ukuba phakathi kwe-ethers ezintathu ze-cellulose ezikhethiweyo, Ikhono lokulibaziseka kwe-hydration ye-c3 kunye ne-samente yasePortland yayinamandla kakhulu kwi-HEC, ilandelwa yi-HEMC, kwaye ibuthathaka kwi-HPMC. Ngokubhekiselele kwi-C3A, amandla amathathu e-cellulose ethers ukukhawulezisa i-hydration nayo ilandelelwano efanayo, oko kukuthi, i-HEC iyona yomeleleyo, i-HEMC yeyesibini, i-HPMC iyona buthathaka kwaye inamandla. Oku kungqinelanise ukuba i-cellulose ether ilibazise ukubunjwa kweemveliso ze-hydration zezinto ze-gelling.

Iimveliso eziphambili ze-hydration zesamente ye-sulfoaluminate yi-ettringite kunye ne-Al (OH) i-3 gel. I-C2S kwisamente ye-sulfoaluminate nayo iya ku-hydrate ngokwahlukileyo ukwenza i-Ca (OH) 2 kunye ne-cSH gel. Ngenxa yokuba i-adsorption ye-cellulose ether kunye ne-ettringite ayinakuhoywa, kwaye i-hydration ye-sulfoaluminate ikhawuleza kakhulu, ngoko ke, kwinqanaba lokuqala le-hydration, i-cellulose ether inefuthe elincinci kwizinga lokukhutshwa kobushushu be-hydration yesamente ye-sulfoaluminate. Kodwa kwixesha elithile le-hydration, kuba i-c2s iya ku-hydrate ngokwahlukileyo ukuvelisa i-Ca (OH) 2 kunye ne-CSH gel, ezi mveliso zimbini ze-hydration ziya kulibaziseka nge-cellulose ether. Ngoko ke, kwaphawulwa ukuba i-cellulose ether ilibazisekile i-hydration ye-samente ye-sulfoaluminate emva kwe-2 h.

4. Isiphelo

Kweli phepha, ngovavanyo lwe-calorimetry ye-isothermal, umthetho wempembelelo kunye nokwakhiwa kwe-cellulose ether kwi-hydration yokushisa kwe-samente ye-Portland eqhelekileyo, i-c3s, i-c3A, i-samente ye-sulfoaluminate kunye nezinye izinto ezahlukeneyo kunye ne-ore enye kwi-72 h yafaniswa. Izigqibo eziphambili zezi zilandelayo:

(1) I-ether ye-Cellulose inokunciphisa kakhulu izinga lokukhutshwa kobushushu be-hydration ye-samente ye-Portland eqhelekileyo kunye ne-tricalcium silicate, kwaye umphumo wokunciphisa izinga lokukhutshwa kobushushu be-tricalcium silicate kubaluleke kakhulu; Isiphumo se-cellulose ether ekunciphiseni izinga lokukhululwa kobushushu besamente ye-sulfoaluminate ibuthathaka kakhulu, kodwa inempembelelo ebuthathaka ekuphuculeni izinga lokukhululwa kobushushu be-tricalcium aluminate.

(2) i-cellulose ether iya kubhengezwa ngezinye iimveliso ze-hydration, ngaloo ndlela ilibazisa i-crystallization yeemveliso ze-hydration, ezichaphazela izinga lokukhutshwa kobushushu be-cement hydration. Uhlobo kunye nobuninzi beemveliso ze-hydration ziyahluka kumacandelo ahlukeneyo e-ore ye-cement bill, ngoko ke umphumo we-cellulose ether kwi-hydration yabo yokushisa ayifani.