Cov Pob Zeb Uas Muab Nws Tus Kheej Sib Nqus (SCC) yog ib lub tshuab siv niaj hnub uas ntws raws li nws qhov hnyav los sau cov formwork yam tsis tas yuav muaj kev co tshuab. Nws cov txiaj ntsig suav nrog kev ua haujlwm tau zoo dua, txo cov nqi zog ua haujlwm, thiab kev ua haujlwm zoo dua. Kev ua tiav cov yam ntxwv no xav tau kev tswj hwm qhov sib tov kom meej, feem ntau nrog kev pab los ntawm cov tshuaj sib xyaw xws li Hydroxypropyl Methylcellulose (HPMC). Cov cellulose ether polymer no ua lub luag haujlwm tseem ceeb hauv kev hloov kho cov khoom rheological ntawm SCC, txhim kho nws qhov ruaj khov thiab cov yam ntxwv ntws.
Cov Khoom thiab Kev Ua Haujlwm ntawm HPMC
Hydroxypropyl Methylcellulose (HPMC) yog ib qho polymer uas tsis yog ionic, yaj tau hauv dej los ntawm cellulose. Nws cov khoom tseem ceeb suav nrog:
Kev Hloov Kho Viscosity: HPMC ua rau kom cov viscosity ntawm cov kua dej nce ntxiv, ua kom zoo dua qhov xwm txheej thixotropic ntawm cov sib tov ua vaj tse.
Kev Khaws Dej: Nws muaj peev xwm khaws dej zoo heev, uas pab tswj kev ua haujlwm ntawm cov pob zeb los ntawm kev txo cov dej evaporation.
Kev nplaum thiab kev sib koom ua ke: HPMC txhim kho kev sib txuas ntawm ntau theem hauv cov pob zeb ua vaj tse, txhim kho nws cov khoom sib koom ua ke.
Kev Txhim Kho Kev Ruaj Ntseg: Nws ua kom cov aggregates nyob ruaj khov hauv qhov sib tov, txo qhov kev sib cais thiab kev los ntshav.
Cov khoom no ua rau HPMC ua ib qho khoom muaj nqis ntxiv hauv SCC, vim nws daws cov teeb meem xws li kev sib cais, kev los ntshav, thiab kev tswj hwm qhov ntws uas xav tau yam tsis muaj kev cuam tshuam rau kev ruaj khov.
Lub Luag Haujlwm ntawm HPMC hauv Kev Sib Txuas Ua Vaj Tse
1. Kev Txhim Kho Kev Ua Haujlwm
Lub luag haujlwm tseem ceeb ntawm HPMC hauv SCC yog los txhim kho nws txoj kev ua haujlwm los ntawm kev ua kom cov khoom sib tov viscosity. Qhov kev hloov kho no tso cai rau SCC kom ntws tau yooj yim hauv qab nws qhov hnyav, sau cov formwork nyuaj thiab ua tiav qib siab ntawm kev sib xyaw yam tsis tas yuav muaj kev co. HPMC ua kom ntseeg tau tias cov pob zeb tseem ua haujlwm tau ntev, uas yog qhov tshwj xeeb tshaj yog rau cov dej loj lossis nyuaj.
Kev Nqus Tau: HPMC pab txhawb rau cov khoom sib xyaw thixotropic, ua rau nws tseem ua kua thaum sib xyaw tab sis tuab thaum sawv. Tus cwj pwm no txhawb nqa SCC tus yam ntxwv tus kheej, ua kom nws ntws zoo kom sau cov pwm thiab qhwv cov hlau txhawb nqa yam tsis muaj kev sib cais.
Kev Sib Xws: Los ntawm kev tswj cov viscosity, HPMC pab tswj kom muaj kev sib xws thoob plaws hauv qhov sib tov, kom ntseeg tau tias txhua pawg ntawm SCC ua kom pom kev ua tau zoo sib xws hauv kev ntws thiab kev ruaj khov.
2. Kev cais tawm thiab kev tswj cov ntshav
Kev sib cais (kev sib cais ntawm cov pob zeb sib xyaw los ntawm cov cement paste) thiab kev ntws (dej nce mus rau saum npoo) yog qhov teeb meem tseem ceeb hauv SCC. Cov xwm txheej no tuaj yeem ua rau lub zog ntawm cov qauv thiab qhov ua tiav ntawm cov pob zeb ua vaj tse puas tsuaj.
Kev Sib Tov Sib Xws: HPMC lub peev xwm los ua kom cov viscosity ntawm cov cement nplaum txo qhov kev txav ntawm dej thiab cov pob zeb sib xyaw, yog li txo qhov kev pheej hmoo ntawm kev sib cais.
Txo Kev Los Ntshav: Los ntawm kev khaws cov dej hauv cov sib tov, HPMC pab tiv thaiv kev los ntshav. Qhov kev khaws cov dej no kuj ua kom ntseeg tau tias cov txheej txheem hydration txuas ntxiv mus zoo, txhim kho kev txhim kho lub zog thiab kev ruaj khov ntawm cov pob zeb.
3. Kev Ruaj Ntseg Zoo Dua
HPMC pab txhawb rau kev ruaj khov ntawm SCC los ntawm kev txhim kho kev sib koom ua ke ntawm cov khoom me me hauv qhov sib tov. Qhov kev ruaj khov ntxiv no yog qhov tseem ceeb hauv kev tswj hwm kev faib tawm ntawm cov khoom sib xyaw thiab tiv thaiv kev tsim cov voids lossis cov chaw tsis muaj zog.
Kev sib koom ua ke: Qhov xwm txheej nplaum ntawm HPMC txhawb kev sib txuas zoo dua ntawm cov cement thiab cov aggregates, ua rau muaj kev sib xyaw ua ke uas tiv taus kev sib cais.
Kev Ruaj Kho: HPMC ua kom lub microstructure ntawm cov pob zeb ruaj khov, tso cai rau kev faib tawm ntawm cov aggregates thiab tiv thaiv kev tsim ntawm laitance (txheej tsis muaj zog ntawm cov cement thiab cov khoom me me ntawm qhov chaw).
Cov nyhuv rau cov khoom siv kho tshuab
1. Lub zog compressive
Qhov cuam tshuam ntawm HPMC rau lub zog compressive ntawm SCC feem ntau yog qhov zoo. Los ntawm kev tiv thaiv kev sib cais thiab ua kom muaj kev sib xyaw ua ke, HPMC pab tswj kev ncaj ncees ntawm cov qauv ntawm cov pob zeb, ua rau muaj cov yam ntxwv zoo dua.
Kev Ua Kom Dej: Kev khaws dej kom zoo dua ua kom muaj kev ua kom cov cement hydrated ntau dua, pab txhawb rau kev tsim cov matrix muaj zog dua.
Kev Ceev Sib Npaug: Kev tiv thaiv kev sib cais ua rau muaj kev faib tawm ntawm cov pob zeb sib npaug, uas txhawb nqa lub zog compressive siab dua thiab txo qhov kev pheej hmoo ntawm cov ntsiab lus tsis muaj zog.
2. Kev ruaj khov
Kev siv HPMC hauv SCC ua rau nws ruaj khov dua los ntawm kev ua kom muaj cov qauv microstructure uas ntom dua thiab sib npaug dua.
Txo Kev Nkag Tau: Kev txhim kho kev sib koom ua ke thiab kev txo qis kev los ntshav ua rau txo qis kev nkag tau ntawm cov pob zeb, ua kom nws tsis kam rau cov yam ntxwv ib puag ncig xws li kev khov-thaw, kev tawm tsam tshuaj lom neeg, thiab carbonation.
Kev Ua Kom Nto Zoo Dua: Kev tiv thaiv kev los ntshav thiab kev sib cais ua kom muaj qhov tiav du thiab ruaj khov dua, uas tsis tshua muaj kev tawg thiab tawg.
Kev Siv thiab Kev Xav Txog Kev Siv Tshuaj
Qhov ua tau zoo ntawm HPMC hauv SCC nyob ntawm nws cov koob tshuaj thiab cov kev xav tau tshwj xeeb ntawm qhov sib tov. Cov nqi tshuaj ib txwm muaj txij li 0.1% txog 0.5% ntawm qhov hnyav ntawm cov cement, nyob ntawm cov khoom xav tau thiab cov yam ntxwv ntawm lwm cov khoom hauv qhov sib tov.
Tsim Kev Sib Tov: Kev tsim kev sib tov ua tib zoo yog qhov tseem ceeb kom ua kom zoo dua cov txiaj ntsig ntawm HPMC. Cov yam xws li hom sib xyaw, cov ntsiab lus ntawm cement, thiab lwm yam admixtures yuav tsum tau txiav txim siab kom ua tiav qhov sib npaug ntawm kev ua haujlwm tau zoo, kev ruaj khov, thiab lub zog.
Kev Sib Xws: HPMC yuav tsum sib xws nrog lwm cov admixtures siv hauv qhov sib tov, xws li superplasticizers thiab cov dej reducers, kom tsis txhob muaj kev sib cuam tshuam tsis zoo uas yuav ua rau kev ua haujlwm ntawm SCC tsis zoo.
Hydroxypropyl Methylcellulose (HPMC) ua lub luag haujlwm tseem ceeb hauv kev txhim kho kev ua tau zoo ntawm Self-Compacting Concrete (SCC). Nws lub peev xwm los hloov pauv viscosity, txhim kho kev khaws dej, thiab ruaj khov qhov sib tov daws cov teeb meem tseem ceeb hauv kev tsim khoom SCC, suav nrog kev sib cais, kev los ntshav, thiab kev tswj hwm kev ntws. Kev koom ua ke ntawm HPMC hauv SCC ua rau muaj kev sib tov ua haujlwm tau zoo dua, ruaj khov, thiab ruaj khov, ua rau nws yog ib qho khoom siv ntxiv rau cov ntawv thov niaj hnub. Kev siv tshuaj thiab kev tsim cov khoom sib tov kom raug yog qhov tseem ceeb los siv tag nrho cov txiaj ntsig ntawm HPMC, kom ntseeg tau tias SCC ua tau raws li cov qauv kev ua tau zoo tshwj xeeb uas xav tau rau ntau yam haujlwm tsim kho.
Lub sijhawm tshaj tawm: Lub Rau Hli-18-2024