Abstract:
Cov kev tsim kho kev ua lag luam ua lub luag haujlwm tseem ceeb hauv kev tsim lub ntiaj teb niaj hnub, ntawm txoj siav twg yog lub tsev thaiv. Rau xyoo, cov kws tshawb nrhiav thiab cov kws tshawb fawb tau txuas ntxiv nrhiav cov hau kev los txhim kho kom zoo thiab ua tau zoo ntawm cov cement. Ib qho kev txhawb nqa Avenue cuam tshuam ntxiv ntawm kev sib ntxiv, ntawm cov calcium no tau dhau los ua tus neeg ua si paub zoo.
Qhia:
Maas yog qhov tseem ceeb ntawm kev tsim kho thiab yuav tsum tau txhim kho kom tau raws li kev hloov pauv kev lag luam. Qhov sib ntxiv ntawm cov kev sib ntxiv tau muaj pov thawj los ua lub tswv yim zoo rau kev txhim kho ntau yam ntawm cov cement. Calcium tsim, ib qho sib xyaw ua los ntawm cov tshuaj tiv thaiv ntawm calcium oxide thiab formic acid, tau nyiam saib xyuas nws cov peev xwm los txhim kho cov khoom ntawm cov cement. Kab lus no ua rau elucitive txoj hauv kev uas calcium tsim zoo zoo cuam tshuam thiab kev ua haujlwm.
Calcium tsim tshuaj tshuaj:
Ua ntej delpving rau hauv cov teebmeem los ntawm calcium tsim rau cov cement, nws yog qhov tseem ceeb kom nkag siab txog cov chemistry ntawm no additive. Calcium tsim yog cov hmoov dawb crystalline nrog cov tshuaj lom neeg ua ke (HCOO) 2. Nws yog dej-soluble thiab muaj hygroscopic cov khoom. Qhov tshwj xeeb ntawm cov calcium thiab tsim ions muab cov khoom tshwj xeeb, ua kom haum rau ntau yam kev siv, suav nrog kev txhim kho ntawm cov cement.
Mechanism:
Qhov muaj kev sib txuam ntawm cov calcium tsim rau hauv cov pajas sib tov qhia tau ntau cov kev ua haujlwm uas ua rau muaj kev ua tau zoo. Ib qho kev siv tshuab loj yuav cuam tshuam cov khoom ua kom muaj dej xis. Calcium tsim cov kev ua raws li catalyst, txhawb nqa kev tsim cov hydrates xws li calcium silicate dej (CSH) thiab Ettringite. Cov txiaj ntsig kev nrawm no hauv lub sijhawm sijhawm nrawm dua thiab nce lub zog ntawm kev ua tau zoo.
Tsis tas li ntawd, calcium tsim cov kev ua raws li lub vev xaib nucleation rau dej nag lossis daus, cuam tshuam rau microstructure ntawm cov xis mas ncej. Qhov kev hloov kho no tau ua rau cov denser thiab ntau dua hluav taws xob hydrate faib tawm, pab txhawm rau txhawm rau txhim kho kev ua kom ruaj khov thiab txo cov neeg siv hluav taws xob.
Ib qho ntxiv, cov tshuaj calcium koom nrog cov kev sib tw ua ke, qhov uas nws nyiam nrog calcium hydroxide los ua CSh Gel. Qhov tshuaj tiv thaiv no tsis yog ua rau muaj kev pheej hmoo ua rau muaj kev pheej hmoo ntawm kev ua kom muaj kev pheej hmoo ntawm kev tsim nyog (Defingite uas tuaj yeem ua rau lub sijhawm ntev ntawm cov cement.
Txhim kho ntawm txoj hmoov xis zoo:
Kev txhim kho lub zog thaum ntxov:
Lub peev xwm ntawm calcium tsim rau instantate Milly Hydration txhais ua kev txhim kho tseem ceeb nyob rau hauv kev txhim kho muaj zog. Qhov no yog qhov tseem ceeb rau kev tsim kho cov dej num uas muaj zog yuav tsum tau nce nrawm. Lub sijhawm nrawm nrawm nce qib los ntawm cov calcium tsim tuaj yeem ua rau muaj kev tshem tawm thiab kev tsim kho sai dua.
Txhim Kho Durability:
Calcium tsim yog ntxiv los hloov cov cement microstructure, uas ua rau muaj cov khoom siv ruaj khov. Qhov nce ntom ntom ntom thiab kev faib tawm tsis sib xws ntawm cov hydrates ntawm hydrates pab txhawb kom muaj kev nce mus rau tshuaj tua neeg, khov-thaw mus ncig, thiab hnav. Yog li ntawd, tus qauv ntawm txoj cai maj mam kho nrog calcium tsim cov kev ua yeeb yam ua yeeb yam pom kev ua haujlwm ntev dua.
Txo permeability:
Ib qho ntawm cov ntsiab lus tseem ceeb uas cuam tshuam rau lub durability ntawm cov pob zeb ua yog nws cov permeability. Calcium tsim kev txo cov permeability los ntawm kev cuam tshuam rau cov qauv pore ntawm Masas Matrix. Qhov tsim ntawm lub dense matrix nrog cov ntxiab ntxiab uas txwv cov dej thiab cov tshuaj txhoj puab, yog li txhim kho cov qhob zog ua kom tsis zoo.
Mitigation ntawm alkali silica tshuaj tiv thaiv (ASR):
Cov kev tshawb fawb tau pom tias cov tshuaj calcium no tuaj yeem txo qhov kev pheej hmoo ntawm alkali-sivection, muaj kev phom sij uas tuaj yeem ua rau o gel tsim thiab tawg hauv pob zeb. Los ntawm kev cuam tshuam rau cov qauv pore cov qauv thiab cov tshuaj lom neeg ntawm cov cement slurry, calcium tsim kev pab txo qis lub peev xwm rau ASR ntsig txog kev puas tsuaj.
Kev Txhim Kho Kev Kawm:
Txhim Kho Tshuab Luam Ntawv:
Cov nyhuv ntawm calcium tsim rau kev ua kom dej xis yog qhov cuam tshuam zoo rau kev ua haujlwm ntawm cov khoom ua haujlwm tshiab. Kev nrawm teem caij nyoog thiab ua kom zoo dua hydration kinincics pab txhim kho kev txhim kho cov yam ntxwv ua, yooj yim tso chaw tso thiab sib dhos ntawm cov pob zeb. Qhov no muaj txiaj ntsig tshwj xeeb tshaj yog qhov kev tso chaw yog qhov tseem ceeb.
Tswj kub:
Kev siv cov calcium tsim nyob rau hauv xis mas pab txo cov kev cuam tshuam ntawm huab cua sov huab cua thaum lub sij hawm kho tau. Lub sij hawm nrawm nrawm ua kom muaj cov qauv calcium tuaj yeem ua kom muaj zog zuj zus thiab txo cov teeb meem hluav taws xob kom sov xws li tawg.
Cov Kev Txiav Txim Siab:
Calcium tsim muaj cov khoom uas tau raws li cov hom phiaj ruaj khov ntawm kev tsim kho kev tsim kho. Nws cov panzzolanic reactivity pab txhawb nqa cov khoom pov tseg, thiab kev cuam tshuam rau kev txo qis ib puag ncig ntawm ib puag ncig kev cuam tshuam nrog kev hloov pauv thiab kho cov qauv laus.
Cov kev sib tw thiab kev saib xyuas:
Thaum cov txiaj ntsig ntawm kev sib xyaw calcium yog qhov tseeb, cov nyom thiab tej yam kev txwv yuav tsum tau txiav txim siab. Cov no yuav suav nrog tus nqi nce, peev xwm sib cuam tshuam nrog lwm cov sib tov, thiab qhov xav tau kev tswj hwm cov kev tswj hwm kom tsis txhob muaj kev tswj hwm tsis zoo. Tsis tas li ntawd, kev ua tau ntev ntev thiab kav ntev ntawm cov khoom lag luam calcium-kho kom haum rau ib puag ncig ib puag ncig kev tshawb fawb thiab kev tshawb fawb ua teb.
Hauv kev xaus:
Kev koom ua ke calcium tsim rau hauv Caas yog txoj hauv kev cuam tshuam los txhim kho kom zoo thiab ua tau zoo ntawm cov khoom tsim tsim tseem ceeb no. Los ntawm nws multifaceted mechanism ntawm kev ua, calcium tsim micrevation, suav nrog cov khoom siv hluav taws xob nrawm, suav nrog kev txhim kho lub zog, kom tau txais cov khoom siv hluav taws xob thaum ntxov thiab txo qis. Raws li kev tsim kho kev tsim kho txuas ntxiv mus ntxiv, lub luag haujlwm ntawm cov calcium tsim hauv kev ua kom zoo tshaj plaws hauv kev ua kom tau yooj yim xis. Kev tshawb fawb ntxiv thiab kev siv cov kev siv yuav ua rau muaj peev xwm ntxiv thiab kev ua yeeb yam zoo ntxiv, paving txoj hauv kev rau cov qauv muaj peev xwm ntau dua thiab muaj peev txheej.
Lub Sijhawm Post: Dec-05-2023