Hnub Kawg:11,Dec,2023
Cellulosestau siv ntau ntxiv hauv cov khoom siv cement, tshwj xeeb tshaj yog nyob rau hauv cov mortars qhuav, vim lawv cov dej tuav tau zoo thiab cov nyhuv thickening.Yog li ntawd, lub zog thiab tsim mechanism ntawmcellulose ether hloov cov ntaub ntawv cement-based thiab kev sib cuam tshuam ntawmcellulose ether thiab cov cement slurry tau maj mam dhau los ua qhov tseem ceeb ntawm kev mloog hauv cov khoom siv hauv tsev thiab engineering hauv xyoo tas los no.Ntau qhov kev tshawb fawb tau ua tiav.Ua ke kev tshawb fawb kev nce qib hauv tsev thiab txawv teb chaws, tseem muaj cov teeb meem hauv qab no hauv kev tshawb fawb thiab kev siv ntawmcellulose ether Hloov cov ntaub ntawv cement-based:
1.Muaj ntau homcelluloses.Txawmcelluloses siv hauv cov khoom siv cement tau muab faib ua ntau hom xws li HEC, HEMC thiab HPMC vim lawv qhov kev hloov pauv.Tib homcellulosesmuaj ntau qhov sib txawv ntawm cov qauv molecular, qhov hnyav molecular, qib ntawm kev hloov pauv lossis cov ntsiab lus hloov pauv.Tam sim no, feem ntau kev tshawb fawb hauv tsev thiab txawv teb chaws tsom rau ib lossis ob pebcelluloses.Qhov kev xaiv ntawmcellulose ether yog txwv rau lawv daim ntawv thov.Cov qauv molecular yam ntxwv ntawmcelluloses tsis tau qhia, thiab lawv tus sawv cev tsis yog tus sawv cev.Qhov kev txiav txim siab yog qhov tshwm sim tsis tau ntawm "kev hloov pauv ib nrab", thiab muaj kev tsis sib haum xeeb thiab kev tsis sib haum xeeb ntawm cov txiaj ntsig kev xeem.Yog li ntawd, nws yog ib qho tsim nyog yuav tsum tau kawm systematically kawm cov kev faib tawm thiab cov yam ntxwv thiab cov txheej txheem ntawm ntau homcellulose ether hloov cov ntaub ntawv gelling.
2.Cov ntaub ntawv uas twb muaj lawm tau kawm txog qhov cuam tshuam ntawmcelluloses ntawm ntau yam khoom ntawm cementitious cov ntaub ntawv, thiab ua ib qho kev ntsuam xyuas ntawm nws cov txheej txheem tsim, tab sis ua tsis tiav los txiav txim siab txog kev sib raug zoo ntawm cov qauv molecular.celluloses thiab cov khoom ntawm kev hloov kho cement slurry.tsis tu ncua, thiab muaj qhov sib txawv pom tseeb hauv lawv cov txheej txheem.Ntawmcellulose ether-Modified cement-based cov ntaub ntawv, muaj ob peb txoj kev tshawb fawb ntawm cov ntaub ntawv nrog cov qauv molecular sib txawv, uas tsis tuaj yeem piav qhia txog kev tsim cov txheej txheem ntawm ntau yam khoom ntawmcellulose ether- hloov cov khoom siv cement..Txawm hais tias qee cov ntaub ntawv tau pom qhov ntawdcelluloses nrog cov qauv molecular sib txawv muaj qhov sib txawv ntawm cov dej ntawm cov cement, cov laj thawj hauv qab tseem tsis tau piav qhia ntxiv.
3.Lub mechanism ntawm kev cuam tshuam ntawmcellulose ether ntawm cement hydration kinetics tseem yuav tau kawm ntxiv.Tam sim no, hais txog lub ncua hydration mechanism ntawmcellulose ether, txawm hais tias adsorption raug suav tias yog qhov ua rau qeeb hydration ntawmcellulose ether, nws pom tias muaj zog dua qhov muaj peev xwm adsorption ntawm hydration khoom thiabcellulose ether, ntau qeeb hydration ntawm cement.Lub adsorption mechanism ntawmcelluloses thiab cement hydration khoom, nrog rau cov laj thawj rau qhov sib txawv adsorption muaj peev xwm sib txawvcelluloses thiab cement hydration khoom, tsis tau kawm ntxiv.
4.Cov ntaub ntawv uas twb muaj lawm qhia tau hais tiascelluloses tuaj yeem cuam tshuam qhov pore qauv ntawm cov khoom siv cement.Celluloses tseem ntseeg tau tias yog nto-ua haujlwm thiab muaj huab cua nkag rau ntawm cov cement slurries tshiab, yog li ua kom cov porosity ntawm hardened cement slurries.Txawm li cas los xij, kev cuam tshuam ntawmcelluloses ntawm qhov tsis tu ncua thiab tsim mechanism ntawm cement slurry pore loj faib tsis tshua muaj kev sib tham.
5. Rheological zog yog ib qho tseem ceeb ntawm daim ntawv thov ntawmcelluloses hauv cov khoom siv cement.Hmoov tsis zoo, muaj qee qhov kev tshawb fawb txog rheological zog ntawmcellulose ether hloov cov cement slurry hauv tsev thiab txawv teb chaws.
Lub sij hawm xa tuaj: Dec-11-2023