Lub mechanism ntawm hydroxypropyl methylcellulose retarding cement hydration
Hydroxypropyl Methylcellulose (HPMC) feem ntau siv rau hauv cov ntaub ntawv siv hauv kev tsim kho, suav nrog cov qauv cement, vim nws muaj peev xwm hloov kho cov khoom rheological thiab kev ua tau zoo ntawm cov ntaub ntawv no. Thaum nws los txog rau kev ncua kev ua kom cov cement hydration, HPMC ua haujlwm los ntawm ntau txoj hauv kev:
Kev Khaws Dej:
HPMC yog hydrophilic thiab muaj peev xwm khaws dej tau zoo. Thaum ntxiv rau hauv cov khoom sib xyaw ua los ntawm cement, nws tuaj yeem nqus thiab khaws dej, tsim cov qauv zoo li gel. Lub peev xwm khaws dej no ua rau qeeb qeeb ntawm kev ua pa ntawm cov dej los ntawm cov khoom sib xyaw, ua rau cov dej muaj nyob ntev dua rau cov txheej txheem hydration.
Kev Tsim Ib Lub Rooj Tiv Thaiv:
HPMC tuaj yeem tsim ib daim nyias nyias nyob ib puag ncig cov cement me me, ua haujlwm ua ib qho thaiv uas txwv tsis pub dej thiab cement sib cuag ncaj qha. Qhov thaiv no txo qhov muaj dej rau cov cement me me, ua rau cov tshuaj tiv thaiv dej qeeb.
Kev ncua sijhawm ntawm lub sijhawm teeb tsa thawj zaug:
Kev ntxiv HPMC rau hauv cov qauv cement tuaj yeem ua rau lub sijhawm teeb tsa thawj zaug qeeb. Lub sijhawm teeb tsa thawj zaug yog lub sijhawm uas cov tshuaj nplaum cement hloov pauv ntawm yas mus rau lub xeev teeb tsa. HPMC tuaj yeem ncua cov txheej txheem no, muab sijhawm ntau dua rau kev ua haujlwm thiab kev siv cov khoom siv.
Kev Tso Dej Tawm Uas Tswj Tau:
HPMC tuaj yeem tswj tau qhov dej tso tawm thaum lub sijhawm teeb tsa thiab tawv ntawm cov cement. Qhov kev tso tawm tswj tau no ua kom ntseeg tau tias dej muaj maj mam, ua rau muaj kev tswj hwm thiab ntev dua ntawm cov txheej txheem hydration.
Kev sib cuam tshuam nrog C3A hauv Cement:
HPMC tau pom tias cuam tshuam nrog tricalcium aluminate (C3A) hauv cement. Qhov kev cuam tshuam no tuaj yeem ua rau muaj cov khoom zoo li gel rau ntawm qhov chaw ntawm cov khoom C3A, txo lawv cov tshuaj tiv thaiv thiab qeeb qeeb cov theem thaum ntxov ntawm cov cement hydration.
Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias cov txheej txheem tshwj xeeb ntawm kev ncua kev ua kom cov cement hydration yuav txawv raws li hom HPMC siv, nws qhov hnyav molecular, thiab cov koob tshuaj uas suav nrog rau hauv cov cement sib xyaw. Qhov cuam tshuam xav tau ntawm kev ncua kev ua kom cov cement hydration feem ntau yog los txhim kho kev ua haujlwm tau zoo, ncua sijhawm teeb tsa, thiab tso cai rau kev siv zoo dua hauv cov xwm txheej kev tsim kho tshwj xeeb.
Txawm hais tias HPMC muaj txiaj ntsig zoo rau kev tiv thaiv kev ua kom cov cement hydration, nws yog ib qho tseem ceeb uas yuav tsum tswj hwm nws cov tshuaj ntau npaum li cas thiab xav txog qhov yuav tsum tau ua ntawm qhov project. Kev siv HPMC ntau dhau yuav ua rau muaj cov teebmeem tsis xav tau xws li txo qis lub zog compressive lossis qeeb qeeb kev txhim kho lub zog kawg hauv cov cement kho. Yog li ntawd, kev sim thiab kev ua kom zoo yog qhov tsim nyog kom ua tiav qhov kev ua tau zoo hauv kev siv hauv kev tsim kho.
