Cov Lus Qhia Txog:
Kev lag luam kev tsim kho ua lub luag haujlwm tseem ceeb hauv kev tsim lub ntiaj teb niaj hnub no, uas cov cement yog lub hauv paus tseem ceeb ntawm kev tsim kho. Tau ntau xyoo, cov kws tshawb fawb thiab cov engineers tau txuas ntxiv nrhiav txoj hauv kev los txhim kho qhov zoo thiab kev ua tau zoo ntawm cov cement. Ib txoj hauv kev zoo siab yog kev ntxiv cov khoom ntxiv, uas calcium formate tau dhau los ua tus neeg ua si zoo.
qhia txog:
Cement yog ib qho tseem ceeb ntawm kev tsim kho thiab xav tau kev txhim kho tas mus li kom tau raws li qhov xav tau ntawm kev lag luam. Kev ntxiv cov khoom ntxiv tau ua pov thawj tias yog ib qho tswv yim zoo rau kev txhim kho ntau yam ntawm cement. Calcium formate, ib qho tshuaj uas tsim los ntawm kev sib xyaw ntawm calcium oxide thiab formic acid, tau nyiam mloog rau nws lub peev xwm los txhim kho cov yam ntxwv ntawm cement. Tsab xov xwm no lub hom phiaj yog piav qhia txog cov hau kev uas calcium formate cuam tshuam zoo rau qhov zoo thiab kev ua haujlwm ntawm cement.
Cov khoom siv tshuaj lom neeg ntawm calcium formate:
Ua ntej yuav kawm txog cov teebmeem ntawm calcium formate rau cement, nws yog ib qho tseem ceeb kom nkag siab txog cov tshuaj lom neeg ntawm cov tshuaj no. Calcium formate yog cov hmoov dawb crystalline nrog cov mis tshuaj Ca (HCOO) 2. Nws yaj tau hauv dej thiab muaj cov khoom hygroscopic. Kev sib xyaw ua ke ntawm calcium thiab formate ions muab cov khoom tshwj xeeb, ua rau nws haum rau ntau yam kev siv, suav nrog kev txhim kho cement.
Lub Tshuab:
Kev siv calcium formate rau hauv cov cement sib xyaw ua ke ua rau muaj ntau txoj hauv kev uas pab txhawb kev ua haujlwm zoo dua. Ib txoj hauv kev tseem ceeb yog kev ua kom cov cement hydration sai dua. Calcium formate ua haujlwm ua tus catalyst, txhawb kev tsim cov hydrates xws li calcium silicate hydrate (CSH) thiab ettringite. Qhov kev ua kom sai dua no ua rau lub sijhawm teeb tsa sai dua thiab ua rau lub zog loj hlob sai dua.
Ntxiv mus, calcium formate ua haujlwm ua qhov chaw nucleation rau hydrate precipitation, cuam tshuam rau microstructure ntawm cov cement matrix. Qhov kev hloov kho no ua rau muaj kev faib tawm hydrate ntau dua thiab sib npaug, pab txhim kho kev ruaj khov thiab txo qhov permeability.
Tsis tas li ntawd xwb, calcium formate koom nrog rau hauv cov tshuaj tiv thaiv pozzolanic, qhov twg nws tshuaj tiv thaiv nrog calcium hydroxide los tsim cov CSH gel ntxiv. Cov tshuaj tiv thaiv no tsis yog tsuas yog pab txhawb kev txhim kho lub zog xwb tab sis kuj txo qhov kev pheej hmoo ntawm kev ncua sijhawm ettringite tsim (DEF), ib qho xwm txheej uas tuaj yeem ua rau lub zog ntev ntawm cov cement puas tsuaj.
Kev txhim kho qhov zoo ntawm cov cement:
Kev Loj Hlob Lub Zog Thaum Ntxov:
Lub peev xwm ntawm calcium formate los ua kom cov cement hydration sai dua txhais tau tias muaj kev txhim kho zoo hauv kev loj hlob lub zog thaum ntxov. Qhov no yog qhov tseem ceeb rau cov haujlwm tsim kho uas xav tau lub zog sai. Lub sijhawm teeb tsa sai dua uas txhawb nqa los ntawm calcium formate tuaj yeem ua rau kev tshem tawm cov formwork sai dua thiab kev tsim kho sai dua.
Kev ruaj khov zoo dua:
Calcium formate raug ntxiv los hloov cov qauv cement, ua rau cov khoom siv ruaj khov dua. Qhov ntom ntom thiab kev faib tawm ntawm cov hydrates ua rau muaj kev tiv thaiv ntau dua rau kev tawm tsam tshuaj lom neeg, kev khov-thaw, thiab kev hnav. Yog li ntawd, cov qauv ntawm cov cement kho nrog calcium formate qhia txog lub neej ua haujlwm ntev dua.
Txo qhov permeability:
Ib qho ntawm cov yam tseem ceeb uas cuam tshuam rau qhov ruaj khov ntawm cov pob zeb ua vaj tse yog nws qhov permeability. Calcium formate txo qhov permeability los ntawm kev cuam tshuam rau cov qauv pore ntawm cov cement matrix. Kev tsim cov matrix ntom nrog cov pores me me txwv tsis pub cov dej nkag thiab cov tshuaj lom neeg, yog li ua kom cov pob zeb ua vaj tse tsis kam puas tsuaj.
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 reaction, ib qho txheej txheem tsis zoo uas tuaj yeem ua rau o thiab tawg hauv cov pob zeb ua vaj tse. Los ntawm kev cuam tshuam rau cov qauv pore thiab cov tshuaj lom neeg ntawm cov cement slurry, calcium formate pab txo qhov muaj peev xwm rau kev puas tsuaj ntsig txog ASR.
Kev txhim kho kev ua tau zoo:
Kev siv tshuab tau zoo dua:
Qhov cuam tshuam ntawm calcium formate rau cov cement hydration muaj qhov cuam tshuam zoo rau kev ua haujlwm ntawm cov pob zeb tshiab. Lub sijhawm teeb tsa sai dua thiab kev txhim kho hydration kinetics pab txhim kho cov yam ntxwv ntws, pab txhawb kev tso thiab kev sib sau ua ke ntawm cov pob zeb. Qhov no yog qhov tshwj xeeb tshaj yog qhov yooj yim ntawm kev tso yog qhov tseem ceeb.
kev tswj kub:
Kev siv calcium formate hauv cov cement pab txo cov teebmeem ntawm qhov kub thiab txias thaum lub sijhawm kho. Kev ua kom lub sijhawm teeb tsa sai dua uas ua rau muaj calcium formate tuaj yeem ua kom lub zog loj hlob sai dua thiab txo qhov tsis muaj zog ntawm cov pob zeb rau cov teeb meem ntsig txog qhov kub thiab txias xws li kev tawg thermal.
Kev txiav txim siab txog kev ruaj khov:
Calcium formate muaj cov khoom uas ua tau raws li lub hom phiaj ntawm kev lag luam kev tsim kho. Nws cov pozzolanic reactivity pab txhawb kev siv cov khoom pov tseg, thiab nws qhov cuam tshuam rau kev ruaj khov thiab lub neej ntev pab txhawb rau kev txo qis ntawm cov kev cuam tshuam ib puag ncig uas cuam tshuam nrog kev hloov thiab kho cov qauv qub.
Cov teeb meem thiab kev xav txog:
Txawm hais tias cov txiaj ntsig ntawm kev siv calcium formate rau hauv cov cement yog qhov tseeb, tab sis yuav tsum xav txog cov teeb meem thiab kev txwv. Cov no yuav suav nrog tus nqi nce ntxiv, kev sib cuam tshuam nrog lwm cov khoom sib xyaw, thiab qhov xav tau kev tswj hwm cov tshuaj kom zoo kom tsis txhob muaj cov teebmeem tsis zoo. Tsis tas li ntawd, kev ua tau zoo mus sij hawm ntev thiab kev ruaj khov ntawm cov pob zeb kho calcium formate nyob rau hauv cov xwm txheej ib puag ncig tshwj xeeb xav tau kev tshawb fawb ntxiv thiab kev kawm hauv thaj chaw.
xaus lus:
Kev muab calcium formate rau hauv cov cement yog ib txoj hauv kev zoo los txhim kho qhov zoo thiab kev ua tau zoo ntawm cov khoom siv tseem ceeb no. Los ntawm nws cov txheej txheem ua haujlwm ntau yam, calcium formate ua rau cov dej noo sai dua, txhim kho microstructure thiab pab txhawb rau ntau yam khoom zoo, suav nrog kev txhim kho lub zog thaum ntxov, txhim kho kev ruaj khov thiab txo qhov permeability. Raws li kev lag luam kev tsim kho txuas ntxiv mus, lub luag haujlwm ntawm cov khoom ntxiv xws li calcium formate hauv kev txhim kho cov khoom cement yuav tseem ceeb dua. Kev tshawb fawb ntxiv thiab kev siv ua haujlwm yuav tsis muaj qhov tsis ntseeg ntxiv txog qhov muaj peev xwm tag nrho thiab kev siv zoo tshaj plaws ntawm calcium formate hauv cov qauv cement, paving txoj hauv kev rau cov qauv ruaj khov thiab ruaj khov dua.
Lub sijhawm tshaj tawm: Lub Kaum Ob Hlis-05-2023