Dab tsi ntawm cov dej-txo cov neeg ua haujlwm feem ntau siv hauv kev tsim vaj tsev?

 

hom dej-txo tus neeg sawv cev

 

feem ntau siv hauv kev tsim vaj tsev

Lignosulfonate Water Reducer

Naphthalene Formaldehyde

Molasses-Based Water Reducer

Polycarboxylate Dej Reducer

Tam sim no, cov dej txo qis feem ntau suav nrog lignosulfonate-based, naphthalene-based, resin-based, molasses-based, thiab polycarboxylate hom. Txhua hom tuaj yeem muab faib ntxiv rau hauv huab cua-entraining thiab non-air-entraining pawg. Raws li lawv cov txiaj ntsig ntawm kev teeb tsa thiab hardening ceev ntawm cov pob zeb, lawv tuaj yeem muab faib ua peb hom: dav dav, thaum ntxov-lub zog, thiab retarding.

Lignosulfonate Water Reducer

Lub hom phiaj tseem ceeb yog calcium lignosulfonate, cov hmoov xim av-daj tau los ntawm cov kua khib nyiab ntawm cov ntaub ntoo tom qab dej cawv extraction, uas tom qab ntawd evaporated, sulfonated, concentrated, thiab tshuaj tsuag qhuav. Kuj tseem muaj sodium thiab magnesium lignosulfonate dej reducers. Cov tshuaj noj uas tsim nyog yog 0.2%–{4}}.3%, nrog rau cov dej txo qis li ntawm 10%. Yog tias tsis siv cov dej txo qis, qhov slump tuaj yeem nce li ntawm 10 cm, thiab lub zog 28-hnub ntawm pob zeb tuaj yeem nce 10% -20%. Yog tias lub zog tseem tsis tau hloov pauv, kev txuag cement ntawm 10% tuaj yeem ua tiav. Txawm li cas los xij, calcium lignosulfonate muaj qhov cuam tshuam tsis zoo ntawm cov pob zeb, feem ntau ncua sij hawm teem sijhawm los ntawm 1-3 teev, nrog rau cov teebmeem tseem ceeb ntawm qhov kub thiab txias. Kev noj ntau dhau tuaj yeem ua rau mob hnyav. Tsis tas li ntawd, calcium lignosulfonate yog ib qho kev tso dej tawm hauv cov huab cua, ua kom cov huab cua hauv cov pob zeb ua ke los ntawm 2% mus rau 3.6%, uas cuam tshuam rau cov pob zeb ua kom muaj zog tab sis muaj txiaj ntsig zoo tiv thaiv te.

Naphthalene Formaldehyde Dej Reducer

Naphthalene-raws li dej reducers yog tsim los ntawm naphthalene thiab nws homologues, fractionated los ntawm thee tar, thiab ces sulfonated thiab condensed. Lawv muaj cov nyhuv dispersing zoo ntawm cov cement, ua rau txo cov dej zoo dua, txhim kho lub zog, thiab kev txhim kho durability piv rau lignosulfonate, faib lawv ua cov dej ua haujlwm siab. Tus nqi txo cov dej ib txwm muaj tshaj li 15%, nrog lub zog tseem ceeb thaum ntxov thiab 28-hnub lub zog nce ntau dua 20%. Qhov tsim nyog npaum li cas yog kwv yees li 0.5% -1.5%, nrog tus nqi pH ntawm 7-9, ua rau nws tsim nyog rau txhua txoj haujlwm ua vaj tse, tshwj xeeb tshaj yog rau cov pob zeb ua kom muaj zog thiab cov kua dej.

Molasses-Based Water Reducer

Molasses-raws li dej reducers siv cov kua khib nyiab los ntawm kev tsim cov piam thaj los ua cov khoom siv raw, neutralized nrog txiv qaub los ua cov tshuaj ntsev, ua rau cov hmoov nplej xim av los yog muab tshuaj txhuam. Ntxiv nrog rau cov dej-txo kev ua haujlwm, lawv muaj qhov cuam tshuam tseem ceeb, faib lawv ua cov dej txo qis. Lub sijhawm pib thiab zaum kawg yog feem ntau txuas ntxiv los ntawm 3 teev. Qhov kev noj kom haum yog 0.2%–{5}}.3%, nrog rau cov dej txo qis ntawm 6%–10%. Lub 28-hnub lub zog ntawm pob zeb yog txhim kho los ntawm 15%–20%. Yog tias lub zog qub tseem tsis hloov pauv, kwv yees li 10% ntawm cov cement tuaj yeem cawm tau.

Polycarboxylate Dej Reducer

Polycarboxylate cov dej ua tau zoo tshaj plaws muaj cov qauv zoo li cov comb, txhawb cov cement particle dispersion los ntawm electrostatic thiab steric hindrance cuam tshuam, txhim kho kev ua haujlwm ntawm cov pob zeb sib tov. Lawv ua tau zoo txo ​​cov dej haus thiab txhim kho ntau yam khoom ntawm lub cev ntawm pob zeb, suav nrog compressive, tensile, flexural zog, thiab elastic modulus. Lawv kuj txhim kho Frost thiab impermeability ntawm pob zeb. Tsis tas li ntawd, lawv tuaj yeem kho lub sijhawm teeb tsa, txhim kho kev tsim kho, txo cov ntshav, thiab ua kom cov pob zeb ntom ntom, yog li txhim kho nws cov kav ntev. Qhov koob tshuaj zoo yog 0.1%–0.2%. Polycarboxylate dej reducers muaj zog dispersibility, tsawg npaum li cas, tsawg poob poob, zoo compatibility nrog sib txawv cements, thiab tsis ua rau retardation tseem ceeb, nrog me ntsis air-entrainment.