Cov khoom ntawm Cement Paste Hloov los ntawm Cellulose Ether

Los ntawm kev ntsuas cov khoom siv kho tshuab, dej tuav tus nqi, teeb tsa lub sijhawm thiab kub ntawm hydration ntawm cellulose ether nrog cov viscosities sib txawv hauv ntau npaum li cas ntawm cov cement paste, thiab siv SEM los tshuaj xyuas cov khoom siv dej, cov txiaj ntsig ntawm cellulose ether ntawm kev ua haujlwm ntawm cement paste yog kawm.txoj cai ntawm influence.Cov txiaj ntsig tau pom tias qhov sib ntxiv ntawm cov cellulose ether tuaj yeem ncua cov cement hydration, ncua cov cement hardening thiab teeb tsa, txo cov dej kub tso tawm, ua kom lub sijhawm ntev ntawm cov dej kub siab, thiab cov nyhuv retarding nce ntxiv nrog rau qhov nce ntawm ntau npaum thiab viscosity.Cellulose ether tuaj yeem ua rau kom cov dej khaws cia ntawm cov tshuaj khib nyiab, thiab tuaj yeem txhim kho cov dej tuav ntawm cov mortar nrog cov txheej txheem nyias, tab sis thaum cov ntsiab lus siab tshaj 0.6%, qhov nce hauv dej tuav cov nyhuv tsis tseem ceeb;Cov ntsiab lus thiab viscosity yog cov yam ntxwv uas txiav txim siab cov cellulose hloov cement slurry.Nyob rau hauv daim ntawv thov ntawm cellulose ether hloov mortar, qhov ntau npaum thiab viscosity yuav tsum tau txiav txim siab.

Cov lus tseem ceeb:cellulose ether;koob tshuaj;retardation;tuav dej

Kev tsim kho mortar yog ib qho ntawm cov khoom siv tsim nyog rau kev tsim kho.Nyob rau hauv xyoo tas los no, nrog rau kev siv loj ntawm cov ntaub ntawv rwb thaiv tsev ntawm phab ntsa thiab kev txhim kho kev tiv thaiv kev tawg thiab kev tawm tsam ntawm cov phab ntsa sab nraud, cov kev xav tau siab dua tau muab tso rau pem hauv ntej rau kev sib tsoo, kev sib koom ua ke thiab kev tsim kho ntawm mortar.Vim muaj qhov tsis zoo ntawm qhov ziab kom qhuav, tsis zoo impermeability, thiab tsis tshua muaj tensile daim ntawv cog lus lub zog, tsoos mortar feem ntau tsis tuaj yeem ua tau raws li kev tsim kho, lossis ua rau muaj teeb meem xws li poob ntawm cov khoom zoo nkauj.Xws li plastering mortar, vim hais tias lub mortar poob dej sai heev, lub sij hawm teem thiab hardening yog luv, thiab teeb meem xws li tawg thiab hollowing tshwm sim thaum lub sij hawm loj-scale tsim, uas cuam tshuam rau qhov zoo ntawm qhov project.Cov tsoos mortar poob dej sai heev thiab cov cement hydration tsis txaus, ua rau lub sijhawm luv luv ntawm cov cement mortar, uas yog tus yuam sij rau kev ua haujlwm ntawm cov mortar.

Cellulose ether muaj cov nyhuv thickening zoo thiab dej tuav, thiab tau dav siv nyob rau hauv daim teb ntawm mortar, thiab tau dhau los ua ib qho tseem ceeb admixture los txhim kho cov dej tuav ntawm mortar thiab muab kev tsim kho kev ua tau zoo, txo qhov kev tsim kho thiab tom qab siv tshuaj mortar. .Qhov teeb meem ntawm dej poob hauv nruab nrab.Cellulose siv nyob rau hauv mortar feem ntau muaj xws li methyl cellulose ether (MC), hydroxypropyl methyl cellulose (HPMC), hydroxyethyl methyl cellulose ether (HEMC), hydroxyethyl cellulose ether (HEC), thiab lwm yam. Ntawm lawv, HPMC thiab HEMC yog cov siv dav tshaj plaws.

Daim ntawv no tsuas yog kawm txog cov txiaj ntsig ntawm cellulose ether ntawm kev ua haujlwm (dej tuav tus nqi, dej poob thiab sijhawm teem sijhawm), cov khoom siv tshuab (compressive zog thiab tensile bond zog), hydration law thiab microstructure ntawm cement paste.Nws muab kev txhawb nqa rau cov khoom ntawm cellulose ether hloov cement paste thiab muab kev siv rau daim ntawv thov ntawm cellulose ether hloov mortar.

1. Kev sim

1.1 Cov khoom siv raw

Cement: Ordinary Portland cement (PO 42.5) cement tsim los ntawm Wuhan Yadong Cement Company, nrog rau thaj tsam tshwj xeeb ntawm 3500 cm²/g.

Cellulose ether: lag luam muaj hydroxypropyl methylcellulose ether (MC-5, MC-10, MC-20, viscosities ntawm 50,000 Pa·S, 100000 PIB·S, 200000 PIB·S, raws).

1.2 Txoj kev

Cov khoom siv kho tshuab: Hauv cov txheej txheem ntawm kev npaj ua qauv, qhov ntau npaum ntawm cellulose ether yog 0.0% ~ 1.0% ntawm cov cement loj, thiab dej-cement piv yog 0.4.Ua ntej ntxiv dej thiab nplawm, sib tov cov cellulose ether thiab cement sib npaug.Ib qho cement paste nrog cov qauv loj ntawm 40 x 40 x 40 tau siv los kuaj.

Teem sijhawm: Txoj kev ntsuas yog ua raws li GB / T 1346-2001 "Cement Standard Consistency Water Consumption, Teem Sijhawm, Stability Test Method".

Kev tuav dej: Kev ntsuam xyuas cov dej tuav ntawm cov cement paste yog hais txog tus qauv DIN 18555 "Testing method for inorganic cementitious material mortar".

Thaum tshav kub kub ntawm hydration: Qhov kev sim tau txais TAM Air microcalorimeter ntawm TA Instrument Company ntawm Tebchaws Meskas, thiab cov dej-cement piv yog 0.5.

Cov khoom siv dej: Muab cov dej thiab cov cellulose ether sib npaug, tom qab ntawd npaj cov cement slurry, pib lub sijhawm, coj cov qauv ntawm lub sijhawm sib txawv, nres hydration nrog kiag li ethanol rau kev kuaj, thiab dej-cement ratio yog 0.5.

2. Cov txiaj ntsig thiab kev sib tham

2.1 Mechanical Properties

Los ntawm kev cuam tshuam ntawm cellulose ether cov ntsiab lus ntawm lub zog, nws tuaj yeem pom tau tias nrog kev nce ntawm MC-10 cellulose ether cov ntsiab lus, lub zog ntawm 3d, 7d thiab 28d tag nrho txo;cellulose ether txo lub zog ntawm 28d ntau dua.Los ntawm kev cuam tshuam ntawm cellulose ether viscosity ntawm lub zog, nws tuaj yeem pom tias txawm tias nws yog cellulose ether nrog viscosity ntawm 50,000 lossis 100,000 lossis 200,000, lub zog ntawm 3d, 7d, thiab 28d yuav txo.Nws tseem tuaj yeem pom tias cellulose ether Viscosity tsis muaj qhov cuam tshuam loj rau lub zog.

2.2 Teem sijhawm

Los ntawm cov txiaj ntsig ntawm cov ntsiab lus ntawm 100,000 viscosity cellulose ether ntawm lub sijhawm teeb tsa, nws tuaj yeem pom tau tias nrog kev nce ntawm cov ntsiab lus ntawm MC-10, ob qho tib si thawj zaug teeb tsa thiab lub sijhawm teem sijhawm kawg nce.Thaum cov ntsiab lus yog 1%, lub sijhawm pib pib Nws mus txog 510min, thiab lub sijhawm teem sijhawm kawg mus txog 850min.Piv nrog rau qhov khoob, lub sij hawm pib lub sij hawm tau ncua sij hawm los ntawm 210min, thiab lub sij hawm teem zaum kawg tau ncua los ntawm 470min.

Los ntawm kev cuam tshuam ntawm cellulose ether viscosity ntawm kev teeb tsa lub sijhawm, nws tuaj yeem pom tias txawm tias nws yog MC-5, MC-10 lossis MC-20, nws tuaj yeem ncua kev teeb tsa ntawm cov cement, tab sis piv nrog peb lub cellulose ethers, thawj qhov chaw. lub sij hawm thiab qhov kawg teeb tsa Lub sij hawm prolongs nrog nce viscosity.Qhov no yog vim hais tias cellulose ether tuaj yeem adsorbed rau saum npoo ntawm cov cement, yog li tiv thaiv dej los ntawm kev sib cuag nrog cov cement hais, yog li ncua cov cement hydration.Qhov ntau dua qhov viscosity ntawm cellulose ether, lub thicker lub adsorption txheej nyob rau saum npoo ntawm cov cement hais, thiab qhov tseem ceeb ntawm cov nyhuv retarding.

2.3 Tus nqi tuav dej

Los ntawm txoj cai tswjfwm ntawm cellulose ether cov ntsiab lus ntawm cov dej khaws cia, nws tuaj yeem pom tau tias nrog kev nce ntawm cov ntsiab lus, cov dej tuav tus nqi ntawm mortar nce, thiab thaum cov ntsiab lus cellulose ether ntau dua 0.6%, cov dej tuav tau yog. ruaj khov hauv cheeb tsam.Txawm li cas los xij, muab piv rau peb cov cellulose ethers, muaj qhov sib txawv ntawm cov viscosity ntawm cov dej tuav tus nqi.Raws li tib qhov ntau npaum li cas, kev sib raug zoo ntawm tus nqi tuav dej yog: MC-5≤MC-10≤MC-20.

2.4 Thaum tshav kub kub hydration

Los ntawm cov nyhuv ntawm cellulose ether hom thiab cov ntsiab lus ntawm cov cua sov ntawm hydration, nws tuaj yeem pom tau tias nrog kev nce ntawm MC-10 cov ntsiab lus, cov cua kub ntawm cov dej ntws tawm maj mam txo, thiab lub sij hawm ntawm hydration kub ncov hloov tom qab;Cov cua sov ntawm hydration kuj muaj kev cuam tshuam zoo.Nrog rau qhov nce ntawm viscosity, qhov kub ntawm hydration txo qis heev, thiab lub ncov ntawm hydration kub hloov pauv loj heev tom qab.Nws qhia tau hais tias cellulose ether tuaj yeem ncua cov cement hydration, thiab nws cov nyhuv retarding muaj feem xyuam rau cov ntsiab lus thiab viscosity ntawm cellulose ether, uas yog raws li kev soj ntsuam ntawm lub sij hawm teem.

2.5 Kev soj ntsuam ntawm cov khoom siv dej

Los ntawm SEM tsom xam ntawm 1d hydration khoom, nws pom tau hais tias thaum 0.2% MC-10 cellulose ether ntxiv, ib tug loj npaum li cas ntawm unhydrated clinker thiab ettringite nrog crystallization zoo dua tuaj yeem pom.%, ettringite crystals yog txo qis, uas qhia tau hais tias cellulose ether tuaj yeem ncua lub hydration ntawm cement thiab tsim cov khoom hydration tib lub sijhawm.Los ntawm kev sib piv peb hom cellulose ethers, nws tuaj yeem pom tias MC-5 tuaj yeem ua rau crystallization ntawm ettringite nyob rau hauv cov khoom hydration ntau dua, thiab cov crystallization ntawm ettringite yog ntau zaus.muaj feem xyuam rau lub thickness ntawm txheej.

3. Cov lus xaus

ib.Qhov sib ntxiv ntawm cellulose ether yuav ncua lub hydration ntawm cov cement, ncua lub hardening thiab chaw ntawm cov cement, txo cov cua sov tso tawm ntawm hydration, thiab ncua lub sij hawm zoo li hydration kub ncov.Nrog rau qhov nce ntawm ntau npaum thiab viscosity, cov nyhuv retarding yuav nce.

b.Cellulose ether tuaj yeem ua rau kom cov dej khaws cia ntawm cov tshuaj khib nyiab, thiab tuaj yeem txhim kho cov dej tuav ntawm mortar nrog nyias txheej txheej.Nws cov dej khaws cia muaj feem xyuam nrog kev siv tshuaj thiab viscosity.Thaum cov koob tshuaj ntau tshaj 0.6%, cov nyhuv tuav dej tsis nce ntau.