Abstract:
Kev tsim kho kev lag luam plays lub luag haujlwm tseem ceeb hauv kev tsim lub ntiaj teb niaj hnub no, uas cov cement yog lub hauv paus tsev thaiv. Tau ntau xyoo, cov kws tshawb fawb thiab engineers tau txuas ntxiv mus nrhiav txoj hauv kev los txhim kho qhov zoo thiab kev ua haujlwm ntawm cov cement. Ib txoj kev vam meej yuav muaj kev sib ntxiv ntawm cov tshuaj ntxiv, ntawm cov calcium formate tau dhau los ua tus neeg paub zoo.
qhia:
Cement yog ib qho tseem ceeb ntawm kev tsim kho thiab xav tau kev txhim kho txuas ntxiv kom tau raws li qhov kev hloov pauv ntawm kev lag luam. Qhov sib ntxiv ntawm cov khoom siv ntxiv tau ua pov thawj tias yog lub tswv yim zoo rau kev txhim kho ntau yam ntawm cov cement. Calcium formate, ib qho chaw tsim los ntawm cov tshuaj tiv thaiv ntawm calcium oxide thiab formic acid, tau nyiam cov xim rau nws lub peev xwm los txhim kho cov khoom ntawm cov cement. Tsab ntawv xov xwm no yog txhawm rau txheeb xyuas txoj hauv kev uas calcium formate zoo cuam tshuam rau cov cement zoo thiab kev ua haujlwm.
Calcium formate tshuaj muaj zog:
Ua ntej delving rau hauv cov teebmeem ntawm calcium formate ntawm cov cement, nws yog ib qho tseem ceeb kom nkag siab txog chemistry ntawm cov tshuaj ntxiv no. Calcium formate yog dawb crystalline hmoov nrog cov tshuaj formula Ca (HCOO) 2. Nws yog dej-soluble thiab muaj hygroscopic zog. Kev sib xyaw tshwj xeeb ntawm calcium thiab formate ions muab cov khoom sib xyaw tshwj xeeb, ua rau nws haum rau ntau yam kev siv, suav nrog kev txhim kho cov cement.
Mechanism:
Kev koom ua ke ntawm calcium formate rau hauv cov cement sib tov qhia ntau lub tswv yim uas pab txhawb kev ua haujlwm tau zoo. Ib qho tseem ceeb mechanism yuav tsum ceev cov cement hydration. Calcium formate ua raws li cov catalyst, txhawb kev tsim cov hydrates xws li calcium silicate hydrate (CSH) thiab ettringite. Qhov no acceleration ua rau lub sij hawm teem ceev thiab nce lub zog thaum ntxov.
Tsis tas li ntawd, calcium formate ua raws li qhov chaw nucleation rau hydrate nag lossis daus, cuam tshuam rau microstructure ntawm cov cement matrix. 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.
Tsis tas li ntawd, calcium formate koom nrog cov tshuaj tiv thaiv pozzolanic, qhov twg nws hnov mob nrog calcium hydroxide los tsim CSH gel ntxiv. Cov tshuaj tiv thaiv no tsis tsuas yog pab txhawb kev loj hlob ntawm lub zog tab sis kuj txo qhov kev pheej hmoo ntawm ncua sij hawm ettringite tsim (DEF), ib qho tshwm sim uas tuaj yeem cuam tshuam rau lub sij hawm ntev ntawm cov cement.
Kev txhim kho ntawm cov cement zoo:
Kev Txhim Kho Thaum Ntxov Muaj Zog:
Lub peev xwm ntawm calcium formate kom ceev cov cement hydration txhais rau hauv kev txhim kho tseem ceeb hauv kev loj hlob thaum ntxov. Qhov no yog ib qho tseem ceeb rau kev tsim kho tej yaam num uas lub zog yuav tsum tau txais sai sai. Lub sijhawm teem sijhawm nrawm txhawb los ntawm calcium formate tuaj yeem ua rau kev tshem tawm cov formwork sai dua thiab kev tsim kho sai dua.
Ua kom durability:
Calcium formate yog ntxiv los hloov cov cement microstructure, ua rau cov khoom siv ruaj khov dua. 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, cov qauv ntawm cov cement kho nrog calcium formate nthuav qhia lub neej ntev dua.
Txo permeability:
Ib tug ntawm cov tseem ceeb yam uas cuam tshuam rau lub durability ntawm pob zeb yog nws permeability. Calcium formate txo permeability los ntawm kev cuam tshuam cov pore qauv ntawm cov cement matrix. Kev tsim cov matrix ntom ntom nrog cov pores zoo dua txwv cov dej nkag thiab cov khoom hnyav, yog li txhim kho cov pob zeb ua haujlwm tsis zoo.
Kev txo qis ntawm Alkali Silica Reaction (ASR):
Cov kev tshawb fawb tau pom tias calcium formate tuaj yeem txo qhov kev pheej hmoo ntawm alkali-silica cov tshuaj tiv thaiv, cov txheej txheem teeb meem uas tuaj yeem ua rau o gel tsim thiab tawg hauv pob zeb. Los ntawm kev cuam tshuam cov qauv pore thiab tshuaj lom neeg muaj pes tsawg leeg ntawm cov cement slurry, calcium formate pab txo qhov muaj peev xwm rau ASR ntsig txog kev puas tsuaj.
Txhim khu kev ua tau zoo:
Txhim kho machinability:
Cov nyhuv ntawm calcium formate ntawm cov cement hydration muaj qhov cuam tshuam zoo rau kev ua haujlwm ntawm cov pob zeb tshiab. Lub sijhawm teem sijhawm nrawm thiab txhim kho hydration kinetics pab txhim kho cov yam ntxwv ntws, ua kom yooj yim tso thiab compaction ntawm pob zeb. Qhov no muaj txiaj ntsig tshwj xeeb yog qhov yooj yim ntawm kev tso kawm yog qhov tseem ceeb.
tswj qhov kub thiab txias:
Kev siv cov calcium formate hauv cov cement pab txo cov teebmeem ntawm qhov kub thiab txias thaum lub sijhawm kho. Ua kom lub sijhawm teem sijhawm ua rau calcium formate tuaj yeem ua kom lub zog loj hlob tuaj thiab txo qis qhov tsis zoo ntawm cov pob zeb rau cov teeb meem kub xws li thermal tawg.
Sustainability xav txog:
Calcium formate muaj cov khoom uas ua tau raws li lub hom phiaj ntawm kev tsim kho kev lag luam. Nws cov pozzolanic reactivity pab txhawb kev siv cov khoom pov tseg, thiab nws cov kev cuam tshuam rau kev ua haujlwm ntev thiab kev ua haujlwm ntev ua rau kev txo qis ntawm ib puag ncig cuam tshuam nrog kev hloov thiab kho cov qauv kev laus.
Cov kev sib tw thiab kev txiav txim siab:
Thaum cov txiaj ntsig ntawm kev sib koom ua ke calcium formate rau hauv cov cement yog qhov tseeb, cov kev cov nyom thiab cov kev txwv yuav tsum raug txiav txim siab. Cov no tuaj yeem suav nrog cov nqi nce ntxiv, muaj peev xwm cuam tshuam nrog lwm cov khoom sib tov, thiab xav tau kev tswj xyuas kom zoo kom tsis txhob muaj qhov tsis zoo. Tsis tas li ntawd, kev ua haujlwm ntev thiab ua haujlwm ntev ntawm calcium formate-kho ua vaj tse nyob rau hauv ib puag ncig tshwj xeeb tau lees paub ntxiv kev tshawb fawb thiab kev tshawb fawb.
nyob rau hauv xaus:
Kev sib xyaw calcium formate rau hauv cov cement yog ib txoj hauv kev zoo los txhim kho qhov zoo thiab kev ua haujlwm ntawm cov khoom siv tseem ceeb no. Los ntawm nws cov txheej txheem ntau yam ntawm kev ua, calcium formate accelerates hydration, txhim kho microstructure thiab pab txhawb rau ntau yam khoom tsim nyog, suav nrog kev txhim kho thaum ntxov, txhim kho durability thiab txo permeability. Raws li kev tsim kho kev lag luam txuas ntxiv mus, lub luag haujlwm ntawm cov khoom siv ntxiv xws li calcium formate hauv kev ua kom cov cement zoo yog qhov tseem ceeb zuj zus. Kev tshawb fawb ntxiv thiab kev siv tswv yim yuav tsis muaj tseeb yuav nthuav qhia tag nrho cov peev xwm thiab kev pom zoo ntawm calcium formate hauv cov cement formulations, paving txoj kev rau ntau resilient thiab sustainable lug.
Post lub sij hawm: Dec-05-2023