Xaiv cov cement thiab dej txo tus neeg sawv cev

Cov dej reducers yog cov khoom siv ntxiv uas txo cov dej sib xyaw hauv cov pob zeb ua ke thaum tswj qhov kev poob qis. Lawv yog cov feem ntau siv thiab feem ntau siv hom qhob admixture. Txawm hais tias ntawm cov khoom siv dej zoo sib xws, qhov ua tau zoo tuaj yeem sib txawv ntawm cov hom sib txawv. Yog li ntawd, thaum lub sij hawm pom zoo npaum li cas nyob rau hauv cov lus qhia ntawm cov khoom yuav siv tau rau me me tej yaam num, rau cov tej yaam num loj, tshwj xeeb tshaj yog nyob rau hauv lub structural pob zeb, yuav tsum tau soj ntsuam qhov tsim nyog. Qhov sib xyaw ua ke piv tsim yuav tsum tsis txhob raug saib xyuas. Cov hauv qab no qhia txog cov ntsiab lus tseem ceeb ntawm kev sib xyaw ua ke tsim qauv rau cov pob zeb uas muaj cov dej txo qis, muab faib ua ob ntu: "Kev Xaiv Khoom" thiab "Siv".

1. Kev xaiv cov cement thiab dej reducer

Kev xaiv cov additives yuav tsum tau ua raws li ob qho tib si technical thiab economic kev txiav txim siab. Cov dej reducers yog tsim rau txhua hom kev ua vaj tse thiab cov pob zeb ua vaj tse, thiab yog tias siv kom raug, lawv tuaj yeem siv yuav luag txhua qhov chaw. Txawm li cas los xij, qhov kev xaiv zaum kawg yuav tsum nyob ntawm seb qhov kev sib piv cov txiaj ntsig nrog cov kev siv cov pob zeb tuaj yeem ua tau raws li cov kev xav tau ntawm qhov project. Txij li cov dej reducers feem ntau raug sim nrog cov cement hauv zos thaum lawv txoj kev loj hlob, kev hloov ntawm cov cement yuav ua rau cov txiaj ntsig sib txawv. Raws li kev paub dhau los, cov dej txo qis muaj qee yam sib xws nrog cov cement hom, thiab kev xaiv tsis raug ntawm cov cement tuaj yeem cuam tshuam rau kev ua haujlwm ntawm cov dej reducer. Kev ua tau zoo ntawm cov dej reducers tuaj yeem ua tiav raws li hauv qab no:

(1) Dej txo tus nqi

Cov dej txo tus nqi yog ib qho tseem ceeb qhia txog cov khoom zoo. Kev siv dej dav dav ntawm cov dej txo qis tsis tshaj 3%, thiab rau cov dej ua kom muaj txiaj ntsig zoo, qhov ntau npaum li cas qis dua. Cov dej txo qis yuav tsum yog tsawg kawg 20%. Cov dej txo tus nqi tuaj yeem txiav txim siab los ntawm kev sim sib xyaw yooj yim thiab sib piv nrog kev siv sib xyaw. Yog tias qhov txo qis qis, nws qhia tau tias hom cement tsis sib haum nrog cov dej reducer, los yog cov dej reducer nws tus kheej yuav tsis zoo.

(2) Kev poob qis dhau sijhawm

Cov nyhuv ntawm cov dej reducer kuj tseem tshwm sim hauv "lub sij hawm-dependent" slump poob ntawm qhov sib tov. Qee cov dej txo qis muaj cov txiaj ntsig zoo txo ​​cov dej tab sis ua rau cov dej sib tov poob nws txoj haujlwm sai. Lub sij hawm-dependent slump poob nws txawv heev nyob ntawm seb hom cement. Ntau cov dej tsis tu ncua thiab ua haujlwm siab ua haujlwm zoo yuav ua rau kom poob qis, uas tuaj yeem ua rau muaj teeb meem kev tsim kho. Qhov no yog ib qho teeb meem tshwm sim hauv kev siv cov dej reducers. Qee zaum, qhov sib xyaw ua ke tuaj yeem ntsib "kev teeb tsa tsis tseeb" lossis "flash setting." Kev teeb tsa tsis raug tshwm sim thaum gypsum ntxiv rau cov cement thaum lub sij hawm sib tsoo reacts nrog lub siab kub hauv lub zeb (tshaj 150 degree) thiab hloov mus rau hauv cov dej tsis muaj dej, ua rau cov cement teem ntxov ntxov thaum dej ntxiv. Kev teeb tsa tsis raug yog rov qab tau, txhais tau hais tias qhov poob qis tuaj yeem rov qab los ntawm kev sib xyaw.

"Kev teeb tsa tsis raug" tsis cuam tshuam rau cov dej reducer, thaum "flash setting" yog thaum cov tshuaj tiv thaiv ntawm cov cement thiab dej tshwm sim sai heev vim yog cov khoom siv sab hauv thiab sab nraud, ua rau poob ntawm tag nrho cov slump tam sim ntawd. "Flash setting" yog irreversible thiab feem ntau muaj feem xyuam rau kev siv ntawm tej hom dej reducers nyob rau hauv tej yam kev mob. Raws li kev tshawb fawb hauv tsev, cov dej txo qis uas muaj suab thaj lossis lignosulfonates tuaj yeem ua rau "teeb ​​meem tsis tseeb" lossis "flash setting" thaum siv cov cement uas muaj cov dej tsis muaj gypsum. Lub ntsiab yog vim li cas yog tias cov dej reducers no txo ​​cov solubility los yog dissolution tus nqi ntawm anhydrous gypsum, los yog accelerate lub hydration ntawm silicate thiab aluminate minerals. Txawm li cas los xij, tsis muaj "flash setting" tshwm sim thaum cov cement muaj dihydrate gypsum vim tias cov dej txo qis tsis tsuas yog txo nws cov solubility tab sis kuj txhawb nws. Lub sij hawm-dependent slump poob yog qhov tseem ceeb ntawm kev sib raug zoo ntawm cov cement thiab dej reducer. Qhov poob tuaj yeem ntsuas tau los ntawm kev ntsuas qhov poob ntawm cov pob zeb sib xyaw ntawm lub sijhawm sib txawv.

(3) Lub zog

Cov nyhuv ntawm cov dej reducers kuj tuaj yeem pom nyob rau hauv lub zog ntawm cov pob zeb. Cov dej reducers feem ntau txhim kho lub zog nyob rau hauv qhov xwm txheej tas li, yog tias lawv sib haum nrog cov cement. Yog tias lub zog txo qis, nws qhia tias tsis sib haum xeeb ntawm cov cement thiab cov dej reducer.

Xaus

Los ntawm cov saum toj no, nws yog qhov tseeb tias qhov ua tau zoo ntawm cov dej txo qhov kawg yog nyob ntawm "kev sib haum xeeb" ntawm cov dej reducer thiab cov cement. Raws li cov neeg siv ntawm cov cement thiab additives, tsuas yog los ntawm kev sim sib tov tuaj yeem pom cov teeb meem tshwm sim, thiab cov teeb meem kev sib raug zoo tuaj yeem zam tau. Tsuas yog los ntawm kev sim cov neeg siv tuaj yeem xaiv cov cement thiab dej reducer uas sib haum. Qhov no yog qhov tseem ceeb tshwj xeeb hauv Suav teb, qhov ntau ntawm cov khoom sib xyaw silicate cement yog tsim, thiab muaj ntau qhov sib txawv ntawm lawv cov muaj pes tsawg leeg thiab cov khoom. Qhov no ua rau muaj qhov sib txawv tseem ceeb hauv cov teebmeem ntawm cov dej reducers. Tsis tas li ntawd, qhov ntau yam ntawm cov dej reducer hom thiab qhov tsis txaus ntawm kev tshawb fawb hauv lawv cov kev ua tau zoo ua rau cov khoom siv ceev faj xaiv qhov tseem ceeb, tshwj xeeb tshaj yog rau cov haujlwm tseem ceeb. Kev xaiv tsis raug tuaj yeem ua rau muaj teeb meem loj mus ntev.