Pobzeb nplaum yog ib qho ntawm cov kev siv loj tshaj plaws ntawm kev sib xyaw tshwj xeeb qhuav mortar tam sim no. Qhov no yog ib hom cement raws li cov khoom siv cementitious tseem ceeb thiab ntxiv los ntawm cov khoom sib xyaw ua ke, cov dej khaws cia, cov neeg ua haujlwm thaum ntxov, cov hmoov latex thiab lwm cov organic lossis inorganic additives. sib tov. Feem ntau, nws tsuas yog yuav tsum tau tov nrog dej thaum siv. Piv nrog rau cov cement mortar zoo tib yam, nws tuaj yeem txhim kho lub zog ntawm kev sib txuas ntawm cov khoom siv thiab cov substrate, muaj kev ua haujlwm tsis zoo thiab muaj cov dej tsis zoo thiab ua haujlwm kub. Thiab qhov zoo ntawm khov-thaw lub voj voog tiv thaiv, feem ntau yog siv los muab cov vuas vov tsev sab hauv thiab sab nrauv phab ntsa, cov vuas hauv pem teb thiab lwm yam khoom siv kho kom zoo nkauj, dav siv rau sab hauv thiab sab nrauv phab ntsa, hauv pem teb, chav dej, chav ua noj thiab lwm qhov chaw kho kom zoo nkauj architectural, yog tam sim no lub feem ntau dav siv ceramic pobzeb sib txuas cov ntaub ntawv.
Feem ntau thaum peb txiav txim siab qhov kev ua tau zoo ntawm cov pobzeb nplaum, peb tsis tsuas yog them sai sai rau nws txoj haujlwm ua haujlwm thiab muaj peev xwm tiv thaiv zawv zawg, tab sis kuj xyuam xim rau nws lub zog txhua yam thiab lub sijhawm qhib.Cellulose etherNyob rau hauv cov pobzeb nplaum tsis tsuas yog cuam tshuam rau cov khoom siv rheological ntawm cov plooj (porcelain adhesive), xws li kev ua haujlwm du, riam nplaum, thiab lwm yam, tab sis kuj muaj kev cuam tshuam zoo rau cov khoom siv ntawm cov nplais nplaum. Kev cuam tshuam rau lub sijhawm qhib ntawm pobzeb nplaum
Thaum emulsion hmoov thiab cellulose ether co-exist nyob rau hauv ntub mortar, qee cov ntaub ntawv qhia tau hais tias emulsion hmoov muaj zog kinetic zog los txuas rau cement hydration cov khoom, thiab cellulose ether muaj ntau nyob rau hauv cov kua interstitial, uas cuam tshuam rau lub mortar ntau viscosity thiab teem sij hawm. Qhov nro ntawm cellulose ether yog siab dua li ntawm emulsion hmoov, thiab ntau cellulose ether enrichment ntawm mortar interface yuav muaj txiaj ntsig zoo rau kev tsim cov hydrogen bonds ntawm lub hauv paus nto thiab cellulose ether.
Nyob rau hauv lub mortar ntub dej, cov dej nyob rau hauv lub mortar evaporates, thiab cellulose ether yog enriched rau ntawm qhov chaw, thiab ib tug zaj duab xis yuav tsim nyob rau ntawm qhov chaw ntawm lub mortar nyob rau hauv 5 feeb, uas yuav txo tau cov tom ntej no evaporation tus nqi, raws li cov dej ntau dua. tshem tawm ntawm cov mortar thicker Ib feem ntawm nws migrates mus rau lub thinner mortar txheej, thiab cov zaj duab xis tsim nyob rau hauv thaum pib yog ib nrab yaj, thiab cov migration ntawm dej yuav coj ntau cellulose ether enrichment nyob rau hauv mortar nto.
Yog li ntawd, zaj duab xis tsim ntawm cellulose ether nyob rau saum npoo ntawm mortar muaj kev cuam tshuam zoo rau kev ua haujlwm ntawm mortar.
1) Cov zaj duab xis tsim yog nyias dhau thiab yuav yaj ob zaug, tsis tuaj yeem txwv cov evaporation ntawm dej thiab txo lub zog.
2) Cov zaj duab xis tsim yog tuab heev, qhov concentration ntawm cellulose ether nyob rau hauv lub mortar interstitial kua yog siab, thiab viscosity siab, yog li nws tsis yooj yim rau tawg zaj duab xis nto thaum cov vuas yog pasted.
Nws tuaj yeem pom tias cov yeeb yaj kiab tsim cov khoom ntawm cellulose ether muaj kev cuam tshuam ntau dua rau lub sijhawm qhib. Hom cellulose ether (HPMC, HEMC, MC, thiab lwm yam) thiab cov degree ntawm etherification (substitution degree) ncaj qha cuam tshuam rau cov yeeb yaj kiab-tsim cov khoom ntawm cellulose ether, thiab hardness thiab toughness ntawm zaj duab xis.
Ntxiv nrog rau kev muab cov khoom siv tau hais los saum toj no rau cov tshuaj khib nyiab, cellulose ether kuj tseem ncua cov dej kinetics ntawm cov cement. Cov nyhuv retarding no feem ntau yog vim qhov adsorption ntawm cellulose ether molecules ntawm ntau theem ntxhia hauv cov cement system tau hydrated, tab sis feem ntau hais lus, qhov kev pom zoo yog tias cellulose ether molecules feem ntau adsorbed ntawm dej xws li CSH thiab calcium hydroxide. Ntawm cov khoom siv tshuaj, nws tsis tshua muaj adsorbed ntawm thawj theem ntxhia ntawm clinker. Tsis tas li ntawd, cellulose ether txo qhov kev txav mus los ntawm ions (Ca2+, SO42-, ...) hauv cov pore tov vim qhov nce hauv cov viscosity ntawm cov pore tov, yog li ntxiv ncua cov txheej txheem hydration.
Viscosity yog lwm qhov tseem ceeb, uas sawv cev rau cov yam ntxwv ntawm cov cellulose ether. Raws li tau hais los saum toj no, cov viscosity feem ntau cuam tshuam rau cov dej khaws cia thiab tseem muaj txiaj ntsig zoo rau kev ua haujlwm ntawm cov mortar tshiab. Txawm li cas los xij, cov kev tshawb fawb sim tau pom tias cov viscosity ntawm cellulose ether yuav luag tsis cuam tshuam rau cov cement hydration kinetics. Qhov hnyav Molecular muaj me ntsis cuam tshuam rau hydration, thiab qhov siab tshaj plaws ntawm qhov sib txawv ntawm qhov hnyav molecular tsuas yog 10min. Yog li ntawd, molecular hnyav tsis yog ib qho tseem ceeb parameter los tswj cov cement hydration.
"Daim ntawv thov ntawm Cellulose Ether hauv Cement-raws li Qhuav-Mixed Mortar Products" tau taw qhia tias kev ua kom rov qab ntawm cellulose ether nyob ntawm nws cov qauv tshuaj. Thiab cov qauv dav dav xaus lus yog tias rau MHEC, qhov siab dua ntawm cov tshuaj methylation, qhov me dua cov nyhuv retarding ntawm cellulose ether. Tsis tas li ntawd, cov nyhuv retarding ntawm hydrophilic hloov pauv (xws li hloov mus rau HEC) muaj zog dua li kev hloov pauv hydrophobic (xws li hloov mus rau MH, MHEC, MHPC). Cov nyhuv retarding ntawm cellulose ether feem ntau cuam tshuam los ntawm ob yam tsis muaj, hom thiab ntau ntawm cov pab pawg hloov.
Cov kev sim ua haujlwm kuj pom tau tias cov ntsiab lus ntawm cov khoom hloov pauv ua lub luag haujlwm tseem ceeb hauv lub zog ntawm cov nplais nplaum. Rau HPMC, yuav tsum muaj qee qhov kev xa khoom los xyuas kom meej tias nws cov dej solubility thiab lub teeb xa mus. Cov ntsiab lus ntawm cov neeg hloov pauv kuj txiav txim siab lub zog ntawm HPMC. Qhov kub ntawm gel kuj txiav txim siab qhov chaw siv ntawm HPMC. Nyob rau hauv ib tug tej yam ntau yam, ib tug nce nyob rau hauv cov ntsiab lus ntawm methoxyl pawg yuav ua rau ib tug downward trend nyob rau hauv lub pull-out zog, thaum ib tug nce nyob rau hauv cov ntsiab lus ntawm hydroxypropoxyl pawg yuav ua rau ib tug txo nyob rau hauv lub zog rub tawm. kev nce qib. Muaj qhov zoo sib xws rau cov sijhawm qhib.
Cov kev hloov pauv ntawm cov neeg kho tshuab lub zog nyob rau hauv lub sijhawm qhib yog zoo ib yam nrog rau hauv qhov kub thiab txias. HPMC nrog cov ntsiab lus siab methoxyl (DS) thiab cov ntsiab lus tsis tshua muaj hydroxypropoxyl (MS) muaj qhov toughness zoo ntawm zaj duab xis, tab sis nws yuav cuam tshuam rau cov mortar ntub ntawm qhov tsis sib xws. khoom wetting zog.
Post lub sij hawm: Dec-12-2022