Abstract:Cellulose ether yog lub ntsiab additive nyob rau hauv npaj-mixed mortar. Cov hom thiab cov yam ntxwv ntawm cellulose ether tau qhia, thiab hydroxypropyl methylcellulose ether (HPMC) raug xaiv los ua cov tshuaj ntxiv rau kev kawm txog kev cuam tshuam ntawm ntau yam khoom ntawm mortar. . Cov kev tshawb fawb tau pom tias: HPMC tuaj yeem txhim kho cov dej khaws cia ntawm mortar, thiab muaj txiaj ntsig ntawm kev txo cov dej. Nyob rau tib lub sijhawm, nws tuaj yeem txo qhov ntom ntawm cov tshuaj khib nyiab sib xyaw, ua kom lub sijhawm teem sijhawm ntawm mortar, thiab txo cov flexural thiab compressive zog ntawm mortar.
Cov lus tseem ceeb:npaj txhij-mixed mortar; Hydroxypropyl methylcellulose ether (HPMC); kev ua tau zoo
0.Ua ntej
Mortar yog ib qho ntawm cov khoom siv dav siv hauv kev tsim kho kev lag luam. Nrog rau kev txhim kho cov ntaub ntawv tshawb fawb thiab kev txhim kho ntawm tib neeg cov kev xav tau ntawm kev tsim vaj tsev zoo, mortar tau maj mam tsim los ntawm kev lag luam ib yam li kev txhawb nqa thiab kev loj hlob ntawm cov pob zeb sib xyaw ua ke. Piv nrog mortar npaj los ntawm cov cuab yeej siv niaj hnub, kev lag luam mortar muaj ntau yam zoo: (a) khoom zoo; (b) ntau lawm efficiency; (c) Tsawg ib puag ncig muaj kuab paug thiab yooj yim rau kev tsim kho vaj tse. Tam sim no, Guangzhou, Shanghai, Beijing thiab lwm lub nroog hauv Suav teb tau txhawb nqa cov khoom sib xyaw ua ke, thiab cov qauv kev lag luam cuam tshuam thiab cov qauv hauv teb chaws tau tshaj tawm los yog yuav muab tawm sai sai.
Los ntawm qhov kev xav ntawm muaj pes tsawg leeg, qhov sib txawv loj ntawm kev npaj sib xyaw mortar thiab cov tshuaj mortar yog qhov sib ntxiv ntawm cov tshuaj lom neeg, cov cellulose ether yog cov tshuaj siv tshuaj ntau tshaj plaws. Cellulose ether feem ntau yog siv los ua tus neeg saib xyuas dej. Lub hom phiaj yog txhawm rau txhim kho kev ua haujlwm ntawm cov khoom sib xyaw ua ke. Tus nqi ntawm cellulose ether yog me me, tab sis nws muaj feem cuam tshuam rau kev ua haujlwm ntawm cov tshuaj khib nyiab. Nws yog ib qho tseem ceeb additive uas cuam tshuam rau kev tsim kho ntawm lub mortar. Yog li ntawd, kev nkag siab ntxiv txog qhov cuam tshuam ntawm cov hom thiab cov yam ntxwv ntawm cellulose ether ntawm kev ua haujlwm ntawm cov cement mortar yuav pab xaiv thiab siv cellulose ether kom raug thiab xyuas kom muaj kev ruaj ntseg ntawm mortar.
1. Hom thiab cov yam ntxwv ntawm cov cellulose ethers
Cellulose ether yog cov khoom siv dej-soluble polymer, uas yog ua los ntawm ntuj cellulose los ntawm alkali dissolution, grafting cov tshuaj tiv thaiv (etherification), ntxuav, ziab, sib tsoo thiab lwm yam txheej txheem. Cellulose ethers muab faib ua ionic thiab nonionic, thiab ionic cellulose muaj carboxymethyl cellulose ntsev. Nonionic cellulose muaj xws li hydroxyethyl cellulose ether, hydroxypropyl methyl cellulose ether, methyl cellulose ether thiab lwm yam. Vim hais tias ionic cellulose ether (carboxymethyl cellulose ntsev) tsis ruaj khov nyob rau hauv lub xub ntiag ntawm calcium ions, nws yog tsis tshua muaj siv nyob rau hauv qhuav hmoov khoom nrog xis mas, slaked txiv qaub thiab lwm yam ntaub ntawv cementing. Cov cellulose ethers siv nyob rau hauv qhuav hmoov mortar yog tsuas yog hydroxyethyl methyl cellulose ether (HEMC) thiab hydroxypropyl methyl cellulose ether (HPMC), uas suav rau ntau tshaj 90% ntawm kev ua lag luam.
HPMC yog tsim los ntawm etherification cov tshuaj tiv thaiv ntawm cellulose alkali activation kev kho mob nrog etherification tus neeg sawv cev methyl chloride thiab propylene oxide. Hauv cov tshuaj tiv thaiv etherification, pawg hydroxyl ntawm cov cellulose molecule yog hloov los ntawm methoxy) thiab hydroxypropyl los ua HPMC. Tus naj npawb ntawm pawg hloov los ntawm pawg hydroxyl ntawm cov cellulose molecule tuaj yeem qhia tau los ntawm qib ntawm etherification (tseem hu ua degree ntawm kev hloov). Lub ether ntawm HPMC Qhov degree ntawm kev hloov tshuaj lom neeg yog nyob nruab nrab ntawm 12 thiab 15. Yog li ntawd, muaj cov pab pawg tseem ceeb xws li hydroxyl (-OH), ether bond (-o-) thiab anhydroglucose nplhaib hauv HPMC qauv, thiab cov pab pawg no muaj qee yam. cuam tshuam rau kev ua haujlwm ntawm lub mortar.
2. Cov nyhuv ntawm cellulose ether ntawm cov khoom ntawm cov cement mortar
2.1 Cov ntaub ntawv raw rau kev xeem
Cellulose ether: tsim los ntawm Luzhou Hercules Tianpu Chemical Co., Ltd., viscosity: 75000;
Cement: Conch hom 32.5 qib composite cement; xuab zeb: nruab nrab xuab zeb; ya tshauv: qib II.
2.2 Cov ntawv xeem
2.2.1 Dej-txo cov nyhuv ntawm cellulose ether
Los ntawm kev sib raug zoo ntawm qhov sib xws ntawm mortar thiab cov ntsiab lus ntawm cellulose ether nyob rau hauv tib qhov sib tov, nws tuaj yeem pom tau tias qhov sib xws ntawm cov tshuaj khib yuav maj mam nce nrog cov ntsiab lus ntawm cellulose ether. Thaum qhov ntau npaum li cas yog 0.3‰, qhov sib xws ntawm cov tshuaj khib yog li 50% siab dua qhov uas tsis muaj kev sib xyaw, uas qhia tau hais tias cellulose ether tuaj yeem txhim kho kev ua haujlwm ntawm mortar. Raws li tus nqi ntawm cellulose ether nce, cov dej siv tau maj mam txo. Nws tuaj yeem suav hais tias cellulose ether muaj qee yam dej-txo cov nyhuv.
2.2.2 Kev tuav dej
Kev tuav dej ntawm mortar yog hais txog lub peev xwm ntawm mortar kom khaws cov dej, thiab nws tseem yog qhov ntsuas kev ua tau zoo los ntsuas qhov ruaj khov ntawm cov khoom siv sab hauv ntawm cov cement mortar tshiab thaum tsheb thauj mus los thiab chaw nres tsheb. Kev tuav dej tuaj yeem ntsuas tau los ntawm ob qhov ntsuas: qib ntawm stratification thiab dej tuav tus nqi, tab sis vim qhov sib ntxiv ntawm cov dej tuav tus neeg sawv cev, cov dej khaws cia ntawm cov khoom sib xyaw npaj tau zoo dua, thiab qib ntawm stratification tsis txaus txaus. los xav txog qhov txawv. Kev ntsuas dej khaws cia yog ntsuas cov dej tuav tus nqi los ntawm kev ntsuas qhov loj ntawm cov ntawv lim ua ntej thiab tom qab cov ntawv lim dej sib cuag nrog thaj tsam ntawm mortar hauv ib lub sijhawm. Vim tias qhov nqus dej zoo ntawm cov ntawv lim dej, txawm tias cov dej khaws cia ntawm cov mortar siab, cov ntawv lim tseem tuaj yeem nqus cov dej noo hauv cov mortar, yog li ntawd. Cov dej tuav tus nqi tuaj yeem cuam tshuam cov dej tuav ntawm lub mortar, qhov siab dua cov dej tuav, qhov dej tuav tau zoo dua.
Muaj ntau txoj hauv kev los txhim kho cov dej tuav ntawm cov tshuaj khib nyiab, tab sis ntxiv cellulose ether yog txoj hauv kev zoo tshaj plaws. Cov qauv ntawm cellulose ether muaj hydroxyl thiab ether bonds. Cov pa oxygen atoms ntawm cov pab pawg no koom nrog cov dej molecules los tsim hydrogen bonds. Ua cov dej dawb molecules rau hauv cov dej khi, thiaj li ua lub luag haujlwm zoo hauv dej tuav. Los ntawm kev sib raug zoo ntawm cov dej tuav tus nqi ntawm mortar thiab cov ntsiab lus ntawm cellulose ether, nws tuaj yeem pom tau tias nyob rau hauv qhov ntau ntawm cov ntsiab lus ntsuas, cov dej tuav tus nqi ntawm mortar thiab cov ntsiab lus ntawm cellulose ether qhia kev sib raug zoo. Qhov siab dua cov ntsiab lus ntawm cellulose ether, qhov ntau dua cov dej tuav tus nqi. .
2.2.3 Qhov ntom ntawm mortar sib tov
Nws tuaj yeem pom los ntawm txoj cai hloov pauv ntawm qhov ntom ntawm cov tshuaj khib nyiab sib xyaw nrog cov ntsiab lus ntawm cellulose ether tias qhov ntom ntawm cov tshuaj khib sib xyaw maj mam txo qis nrog qhov nce ntawm cov ntsiab lus ntawm cellulose ether, thiab ntub ntom ntom ntawm cov mortar thaum cov ntsiab lus. yog 0.3‰o Txo los ntawm 17% (piv nrog tsis muaj kev sib xyaw). Muaj ob qhov laj thawj rau qhov txo qis hauv cov tshuaj khib nyiab: ib qho yog huab cua-entraining nyhuv ntawm cellulose ether. Cov cellulose ether muaj cov pab pawg alkyl, uas tuaj yeem txo lub zog saum npoo ntawm cov tshuaj aqueous, thiab muaj cov nyhuv cua ntawm cov cement mortar, ua rau cov ntsiab lus ntawm cov mortar nce, thiab qhov toughness ntawm cov npuas zaj duab xis kuj siab dua li ntawd. ntawm cov npuas dej ntshiab, thiab nws tsis yooj yim rau paug; Ntawm qhov tod tes, cov cellulose ether nthuav tawm tom qab nqus dej thiab tuav ib qho ntim, uas yog sib npaug rau kev ua kom cov pores sab hauv ntawm cov mortar, yog li nws ua rau cov mortar sib tov ntom ntom.
Cov huab cua-entraining nyhuv ntawm cellulose ether txhim kho kev ua hauj lwm ntawm mortar ntawm ib sab, thiab ntawm qhov tod tes, vim qhov nce ntawm cov ntsiab lus ntawm cov huab cua, cov qauv ntawm lub cev hardened yog loosened, uas ua rau muaj qhov tsis zoo ntawm kev txo qis. mechanical zog xws li lub zog.
2.2.4 Lub sijhawm Coagulation
Los ntawm kev sib raug zoo ntawm lub sijhawm teeb tsa ntawm mortar thiab tus nqi ntawm ether, nws tuaj yeem pom meej tias cellulose ether muaj qhov cuam tshuam rau ntawm mortar. Qhov ntau npaum li cas, qhov pom tseeb dua cov nyhuv retarding.
Cov nyhuv retarding ntawm cellulose ether yog ze ze rau nws cov yam ntxwv. Cellulose ether khaws cov qauv hauv paus ntawm cellulose, uas yog hais tias, cov qauv anhydroglucose nplhaib tseem muaj nyob rau hauv cov qauv molecular ntawm cellulose ether, thiab lub nplhaib anhydroglucose yog qhov ua rau cov pab pawg tseem ceeb ntawm cov cement retarding, uas tuaj yeem tsim cov piam thaj-calcium molecular. Cov tebchaw (los yog complexes) nrog calcium ions nyob rau hauv cov cement hydration aqueous tov, uas txo cov calcium ion concentration nyob rau hauv lub cement hydration induction lub sij hawm thiab tiv thaiv Ca (OH): Thiab calcium ntsev crystal tsim, nag lossis daus, thiab ncua cov txheej txheem ntawm cement hydration.
2.2.5 Lub zog
Los ntawm kev cuam tshuam ntawm cellulose ether ntawm flexural thiab compressive zog ntawm mortar, nws tuaj yeem pom tau tias nrog kev nce ntawm cov ntsiab lus ntawm cellulose ether, 7-hnub thiab 28-hnub flexural thiab compressive zog ntawm mortar tag nrho qhia ib qho kev poob qis.
Yog vim li cas rau qhov txo qis hauv mortar lub zog tuaj yeem raug ntaus nqi los ntawm qhov nce ntawm huab cua cov ntsiab lus, uas ua rau cov porosity ntawm cov mortar hardened thiab ua rau cov qauv sab hauv ntawm lub cev hardened xoob. Los ntawm kev ntsuas regression ntawm cov ntub dej thiab compressive lub zog ntawm ob, lub zog ntub yog tsawg, thiab vice versa, thiab rov ua dua, lub zog yog siab. Huang Liangen siv qhov sib npaug sib npaug ntawm porosity thiab mechanical zog muab los ntawm Ryskewith los txiav txim qhov kev sib raug zoo ntawm lub zog compressive ntawm mortar tov nrog cellulose ether thiab cov ntsiab lus ntawm cellulose ether.
3. Cov lus xaus
(1) Cellulose ether yog derivative ntawm cellulose, muaj hydroxyl,
Ether bonds, anhydroglucose rings thiab lwm pab pawg, cov pab pawg no cuam tshuam rau lub cev thiab lub zog ntawm cov tshuaj khib nyiab.
(2) HPMC tuaj yeem txhim kho cov dej khaws cia ntawm mortar, ua kom lub sijhawm teem sijhawm ntawm mortar, txo qhov ntom ntawm mortar sib tov thiab lub zog ntawm lub cev tawv.
(3) Thaum npaj cov mortar npaj txhij, cellulose ether yuav tsum tau siv kom tsim nyog. daws qhov tsis sib haum xeeb ntawm kev ua haujlwm ntawm mortar thiab cov khoom siv kho tshuab.
Post lub sij hawm: Feb-20-2023