Cov cement-raws cov pobzeb nplaum yog qhov loj tshaj daim ntawv thov ntawm kev sib xyaw tam sim no qhuav-xyaw. Nws yog hom organic los yog inorganic admixture nrog cov cement ua cov tshuaj pleev ib ce, cov dej sawv ntxov tus neeg sawv cev, thaum ntxov lub zog tus neeg sawv cev thiab cov hmoov yas. sib xyaw. Feem ntau, nws tsuas yog xav tau sib xyaw nrog dej. Piv nrog dog dig colut, nws tuaj yeem txhim kho txoj hlua khi ntawm cov khoom thiab cov txheej txheem anti-sli-slied thiab muaj cov dej tsis kam ua tau zoo. Nws tseem siv rau kev kho kom zoo nkauj ntawm sab hauv thiab sab nrauv phab ntsa vuas, cov vuas hauv av thiab lwm cov ntaub ntawv zoo nkauj. Nws yog dav siv nyob rau hauv kev kho kom zoo nkauj ntawm sab hauv thiab phab ntsa sab hauv, plag tsev, chav ua noj, thiab lwm yam yog cov khoom siv dav. Cov khoom siv ua ntawv khi.
Feem ntau, thaum peb txiav txim rau kev ua yeeb yam ntawm cov nplais nplaum, peb yuav tsum them sai sai rau nws cov kev ua haujlwm muaj zog thiab kev ua haujlwm ntawm kev ua haujlwm. Ntxiv rau kev cuam tshuam cov khoom sib dhos ntawm cov roj hmab porcely, xws li cov kab mob ether ether muaj cov khoom muaj zog ntawm cov pobzeb nplaum.
1. Qhib lub sijhawm
ThaumRecispersible polymer hmoovthiabCellulose etherCoexist nyob rau hauv lub txiv ntoo qhuav, ib co cov ntaub ntawv qauv qhia tau tias cov roj hmab hmoov ntxiv tau muab cov khoom siv roj hmab txiv ntoo kom muaj zog ntxiv rau hauv cov kua rau cov kua ntshav, uas cuam tshuam ntau dua. Lub viscosity thiab teeb lub sij hawm ntawm cug cug. Lub nras nro ntawm lub cellulose ether yog loj dua li ntawm cov roj hmab hmoov, thiab txhawb nqa cov roj hmab ntau dua los ua cov kab mob hydrogen nruab nrab thiab lub cellulose ether.
Hauv lub tshuaj khib ntub, cov dej hauv lub capulose alaporates, lub cellulose enrice, thiab ib qho kev txo cov dej evap ntawm 5 feeb, zoo li cov dej ntxiv yog thicker los ntawm tshuaj khib. Ib feem ntawm lub tsiv teb tsaws mus rau txheej thinner ntawm lub tshuaj khib txheej, qhov pib qhib ntawm daim nyias nyias yog qee qhov yuav coj ntau cov cellulose ether rau saum npoo ntawm lub cug.
Zaj duab xis ether rau saum npoo ntawm cug cug muaj qhov muaj txiaj ntsig zoo ntawm kev tshuaj khib:
Ua ntej, cov yeeb yaj kiab tsim tau yuag heev, nws yuav tsis txwv cov dej evaporation, txo lub zog.
Qhov thib ob, cov yeeb yaj kiab tsim yog tuab heev, kev concentration ntawm cellulose kua dej yog qhov siab, thiab viscosity yog loj. Thaum cov pobzeb yog yav dhau los, nws tsis yooj yim los tsoo cov yeeb yaj kiab saum npoo.
Los ntawm qhov no, nws tau to taub tias zaj duab xis tsim cov khoom ntawm lub cellulose ether muaj ib tug loj cuam tshuam rau lub sijhawm qhib. Hom ntawm cellulose ether (HPMC,Tus tseem ceeb, MC, thiab lwm yam) thiab qib kev hloov pauv (Qib ntawm hloov chaw ntawm cov yeeb yaj kiab ether, thiab lub zog thiab tawv ntawm zaj duab xis.
2, lub zog
Ntxiv rau qhov ua kom muaj txiaj ntsig zoo tau piav qhia saum toj no rau lub tshuaj khib, lub cellulose ether setards cov kasging kinetics ntawm cov cement. Qhov kev ua kom rov ua haujlwm no feem ntau yog vim kev tshaj tawm ntawm cellulose ither molecules ntawm ntau yam kev ua dej xis nyob rau ntau yam li CSH thiab calcium hydroxide. Ntawm cov khoom siv tshuaj lom neeg, nws tsis tshua muaj adsorbed ntawm thawj cov chaw ntxhoo ntawm cov clinker. Ib qho ntxiv, vim qhov nce hauv viscosity ntawm cov kev daws teeb meem, lub cellulose ions (ca42-, yog li txuas ntxiv ncua cov txheej txheem hydration.
Viscosity yog lwm qhov tseem ceeb tsis tseem ceeb uas sawv cev cov tshuaj lom neeg ntawm cellulose muaj neeg muaj kev pab. Raws li tau hais los saum no, lub viscosity tsuas yog cuam tshuam rau lub peev xwm kav dej thiab tseem muaj cov txiaj ntsig tseem ceeb ntawm kev ua haujlwm ntawm cov cug cug. Txawm li cas los xij, kev sim tshawb pom tau pom tias cov viscosity ntawm cellulose ether muaj yuav luag tsis cuam tshuam rau ntawm cov cinning kinetics ntawm cov cement. Qhov hnyav molecular muaj me ntsis nyhuv rau kev haus dej, thiab qhov sib txawv loj tshaj plaws ntawm qhov hnyav molecular tsuas yog 10 min. Yog li ntawd, qhov hnyav molecular tsis yog qhov tseem ceeb parameter rau tswj hwm cov xis mas.
"Daim ntawv thov ntawm cellulose ether nyob rau caased cug cov khoom lag luam" kom meej meej hais tias lub cellulation ether nyob ntawm nws cov qauv tshuaj. Qhov ntsuas dav dav tau hais tias rau MHEC, qib siab dua ntawm kev methylation, qhov me me ntawm kev ncua ntawm cellulose ether. Tsis tas li ntawd, Hydrophilic hloov chaw (xws li hloov mus rau HEC) tau hloov dua hydrophobic hloov chaw (xws li hloov mus rau MH, MHEC, MHPC). Cov nyhuv retarding ntawm cellulose ether yog feem ntau cuam tshuam los ntawm ob qho tsis sib xws ntawm hom thiab cov nyiaj ntawm cov pab pawg hloov chaw.
Peb cov kev sim system tau pom tias cov ntsiab lus ntawm cov neeg hloov chaw ua lub luag haujlwm tseem ceeb hauv kev ua haujlwm muaj zog ntawm cov vuas luaj. Peb soj ntsuam kev ua tau zoo ntawm HPMC nrog cov qib sib txawv ntawm kev hloov pauv cov nplais, thiab kuaj lub cellulose ether khub nrog cov pab pawg sib txawv raws li kev kho mob sib txawv. Tus yam ntxwv ntawm cov neeg kho mob cov nplais ntawm cov nplais nplaum, Daim duab 2 thiab daim duab 3 yog cov ntsiab lus ntawm kev rub tawm ntawm cov nplais nplaum ntawm chav tsev.
Naj npawb 2
Naj npawb 3
Hauv kev sim, peb xav txogHydroxyPropylropy Cellulose (HPMC), uas yog ib txoj kev ether. Yog li ntawd, peb yuav tsum tso ob tus lej ua ke. Rau HPMC, peb xav tau ib qho khoom siv los ua kom cov dej so thiab kev hloov chaw. Peb paub cov ntsiab lus ntawm cov hloov chaw. Nws tseem yuav txiav txim siab qhov kub ntawm HPMC, uas txiav txim siab ib puag ncig uas HPMC siv. Yog li ntawd, cov ntsiab lus ntawm feem ntau siv HPMC kuj yog framed nyob rau hauv ib tug ntau. Yuav ua li cas los sib txuas methoxy thiab hydroxyprropoxy pawg nyob rau hauv qhov no kom ua tiav cov txiaj ntsig zoo tshaj plaws yog qhov peb kawm. Daim duab 2 qhia tau tias nyob rau qee qhov, kev nce methoxyl cov ntsiab lus yuav coj mus txog ib qho kev rub lub zog, thaum lub zog hydroxyls yuav nce thiab rub lub zog yuav nce ntxiv. Rau lub sijhawm qhib, muaj cov cuam tshuam zoo.
Lub Sijhawm Post: Dec-18-2018