Hauv kev tsim kho niaj hnub no, cov txheej txheem hauv pem teb uas siv cov cement xws li cov tshuaj sib xyaw ua ke, cov pob zeb hauv pem teb rau kev lag luam, thiab cov tshuaj mortars uas siv los ua kom tiaj tus yuav tsum muaj kev ntws zoo heev thiab kev khaws cia kom tiaj tus mus ntev kom ntseeg tau tias siv tau zoo thiab ua tiav qhov chaw zoo. Ib qho ntawm cov tshuaj ntxiv tseem ceeb tshaj plaws uas siv los ua kom tiav cov yam ntxwv no yogHydroxypropyl Methyl Cellulose (HPMC), ib qho cellulose ether uas yaj tau hauv dej feem ntau siv los ua ib qho thickener, water retention agent, thiab rheology modifier.
1. Qhov Tseem Ceeb ntawm Kev Khaws Cia Cov Dej Ntws Hauv Pem Teb Uas Muaj Cement
Kev khaws cia dej ntws yog qhov tseem ceeb ntawm kev ua tau zoo hauv cov txheej txheem hauv pem teb niaj hnub no, suav nrog cov tshuaj sib xyaw ua ke, cov pob zeb hauv kev lag luam, thiab cov tshuaj kho. Nws hais txog lub peev xwm ntawm cov khoom sib xyaw tshiab los tswj nws cov dej ntws thiab ua haujlwm tau raws li lub sijhawm teev tseg tom qab sib xyaw. Cov yam ntxwv no cuam tshuam ncaj qha rau kev siv tau zoo, qhov zoo ntawm qhov chaw, thiab tag nrho cov khoom siv hauv pem teb tiav.
1.1 Xyuas kom ua haujlwm tau zoo thiab siv tau zoo
Hauv cov haujlwm loj hauv pem teb, cov khoom siv feem ntau raug sib xyaw, thauj mus los, twj, thiab siv rau lub sijhawm ntev. Yog tsis muaj kev khaws cia dej ntws txaus, cov khoom sib xyaw cementitious tuaj yeem poob lawv cov kua dej sai dhau vim yog cov dej noo sai lossis dej poob. Qhov no ua rau muaj teeb meem hauv kev nthuav dav, kev siv tsis sib xws, thiab kev siv zog ntau ntxiv.
Kev khaws cia cov dej ntws kom zoo tso cai rau cov neeg cog lus muaj sijhawm txaus los tuav thiab siv cov khoom siv kom du, ua kom muaj kev ua tau zoo sib xws txij thaum sib tov mus txog rau qhov chaw kawg.
1.2 Ua tiav Kev Ua Tau Zoo ntawm Tus Kheej
Cov txheej txheem hauv pem teb uas nws tus kheej leveling siv zog ntau rau kev ntws mus tas li kom ua tiav qhov chaw du thiab tiaj tus yam tsis tas siv tes ntau. Yog tias qhov ntws tsis zoo, cov khoom siv yuav pib tawv ua ntej nws nthuav dav tag, ua rau muaj qhov tsis zoo ntawm qhov chaw xws li cov kab, tuab tsis sib npaug, lossis tsis leveling tag.
Kev tswj cov dej ntws raws sijhawm ua kom cov khoom siv tuaj yeem sib npaug hauv qab lub ntiajteb txawj nqus, ua rau muaj qhov zoo, sib xws.
1.3 Tiv Thaiv Kev Sib Cais Thiab Kev Los Ntshav
Ib lub tshuab uas siv cov cement sib npaug zoo yuav tsum ua kom sib npaug thaum siv. Kev ntws tsis zoo yuav ua rau cov khoom hnyav dua poob thiab cov khoom sib dua nce siab, lossis ntws tawm, qhov twg cov dej ntau dhau sib sau ua ke rau ntawm qhov chaw.
2. Lub Luag Haujlwm ntawm HPMC hauv Cov Txheej Txheem Ua Los Ntawm Cement
HPMCNws ua lub luag haujlwm tseem ceeb hauv kev tswj hwm tus cwj pwm rheological ntawm cov ntaub ntawv hauv pem teb uas ua los ntawm cement. Nws qhov kev ua tau zoo yog vim nws cov qauv molecular thiab nws txoj kev sib cuam tshuam nrog dej thiab cov khoom cement.
2.1 Lub Tswv Yim Khaws Dej
Ib qho ntawm cov haujlwm tseem ceeb tshaj plaws ntawm HPMC yog nws lub peev xwm khaws dej tau zoo. Thaum ntxiv rau hauv lub kaw lus cementitious, HPMC yaj hauv dej thiab tsim cov kua nplaum colloidal. Cov qauv network no pab ntes cov dej dawb hauv lub kaw lus, txo cov dej evaporation thiab tiv thaiv kev nqus dej sai los ntawm cov khoom siv porous.
Los ntawm kev tswj cov dej noo kom txaus, HPMC ua rau qeeb qeeb ntawm cov dej noo ntawm cov cement, ua rau cov khoom siv ua haujlwm tau ntev dua. Qhov no tseem ceeb heev rau hauv qhov chaw kub lossis qhuav uas cov dej poob sai dua.
2.2 Kev Hloov Kho Rheology thiab Cov Nyhuv Thickening
HPMC hloov pauv cov khoom rheological ntawm cov cement-based sib tov. Nws ua rau viscosity nce thiab qhia txog pseudoplastic (shear-thinning), uas txhais tau tias cov khoom siv yuav tsis viscous ntau thaum shear (piv txwv li, thaum sib tov lossis thov) thiab viscous ntau dua thaum so.
Lub tsev no muaj ob qho txiaj ntsig tseem ceeb:
- Yooj yim ntawm daim ntawv thov: Cov khoom siv ntws tau yooj yim thaum lub sijhawm kis lossis twj
- Kev ruaj khov thaum soCov khoom siv tiv taus kev sib cais thiab tswj kev faib tawm ntawm cov khoom me me
Yog li ntawd, HPMC ua kom ntseeg tau tias cov khoom siv hauv pem teb tuaj yeem ntws tau zoo thaum tseem khaws nws cov qauv tom qab muab tso rau.
2.3 Cov teebmeem tiv thaiv kev sib cais thiab kev tiv thaiv kev los ntshav
Hauv cov txheej txheem ua los ntawm cov cement, kev sib cais (kev sib cais ntawm cov khoom khov thiab cov kua) thiab kev los ntshav (dej nce mus rau saum npoo) yog cov teeb meem uas tshwm sim ntau uas cuam tshuam tsis zoo rau qhov zoo thiab lub zog ntawm qhov chaw.
HPMC pab ua kom cov khoom sib xyaw ruaj khov los ntawm kev ua kom cov khoom sib xyaw ua ke zoo dua thiab txhim kho kev ruaj khov ntawm cov khoom siv. Qhov no txo cov khoom sib sau ua ke thiab tiv thaiv dej kom tsis txhob sib cais ntawm cov khoom sib xyaw, ua kom cov khoom sib xws thiab ruaj khov thoob plaws hauv cov txheej txheem thov.
2.4 Kev Sib Cuam Tshuam Nrog Cement Hydration
HPMC tsis tshua muaj tshuaj lom neeg nrog cov cement tab sis cuam tshuam rau cov txheej txheem hydration los ntawm cov txheej txheem lub cev. Los ntawm kev khaws dej thiab tsim ib zaj duab xis nyob ib puag ncig cov cement, nws qeeb me ntsis qhov kev ua kom hydration.
Qhov kev ncua sij hawm no muaj txiaj ntsig zoo rau kev khaws cia dej vim nws ncua lub sijhawm qhib ntawm cov khoom siv, ua rau muaj kev sib npaug zoo dua thiab ua tiav. Txawm li cas los xij, kev noj tshuaj HPMC ntau dhau tuaj yeem ua rau qeeb dej, uas tuaj yeem cuam tshuam tsis zoo rau kev loj hlob ntawm lub zog thaum ntxov.
3. Kev cuam tshuam ntawm HPM Viscosity thiab Dosage
Kev ua tau zoo ntawm HPMC hauv cov plag tsev cement feem ntau nyob ntawm nws qib viscosity thiab qib koob tshuaj.
- HPMC uas tsis muaj viscosity ntau: Muab qhov tuab nruab nrab thiab tsim nyog rau cov tshuaj sib xyaw ua ke uas xav tau kev ntws siab
- HPMC nruab nrab-viscosity: Muab qhov sib npaug ntawm kev ntws thiab kev ruaj khov, feem ntau siv rau hauv cov mortars hauv pem teb dav dav
- Muaj viscosity siabHPMC: Ua kom cov dej tuav tau zoo dua thiab tiv thaiv kev qaug zog tab sis yuav txo qhov ntws tau yog tias noj ntau dhau
Feem ntau, cov koob tshuaj ntawm HPMC yog txij li 0.05% txog 0.2% ntawm tag nrho cov khoom sib tov qhuav, nyob ntawm cov kev xav tau ntawm cov qauv thiab cov xwm txheej ntawm daim ntawv thov.
4. Tej Yam Ib puag ncig uas cuam tshuam rau kev khaws cia dej ntws
Qhov ua tau zoo ntawm HPMC hauv kev tswj hwm kev ntws kuj tseem cuam tshuam los ntawm cov xwm txheej ib puag ncig xws li:
- KubKub siab ua rau dej evaporation thiab cement hydration sai dua, txo lub sijhawm khaws cia dej ntws
- Av noo: Cov av noo qis ua rau cov dej poob ntawm qhov chaw ntau ntxiv
- Kev nqus dej ntawm cov khoom siv: Cov substrates uas muaj qhov porous heev rub dej los ntawm cov khoom sib tov, ua kom cov tawv nqaij sai dua.
Hauv cov xwm txheej zoo li no, HPMC pab ua kom lub kaw lus ruaj khov los ntawm kev them nyiaj rau qhov poob dej thiab tswj kev ua haujlwm tas mus li.
5. Kev sib koom tes nrog lwm cov khoom ntxiv
HPMC feem ntau siv ua ke nrog lwm cov khoom ntxiv los ua kom zoo dua kev ua tau zoo:
- Hmoov Polymer uas yaj tau dua (RDP): Txhim kho kev nplaum, kev yooj ywm, thiab lub zog kho tshuab
- Cov tshuaj superplasticizers: Txhim kho kev ntws dej yam tsis ua rau cov dej ntau ntxiv
- Cov tshuaj ua npuas ncaujTxo qhov cua nkag thiab txhim kho qhov zoo ntawm qhov chaw
Qhov kev sib koom ua ke ntawm HPMC thiab cov khoom ntxiv no tso cai rau cov neeg tsim cov qauv kom ua tiav qhov sib npaug ntawm kev ntws, lub zog, thiab kev ua haujlwm ntev.
Lub sijhawm tshaj tawm: Plaub Hlis-08-2026