Hom, Action Mechanism, Daim ntawv thov thiab cov qauv ntawm tus neeg saib xyuas dej txo tau raug qhia

Dej reducers yog ib hom qhob additive siv nyob rau hauv cov ntaub ntawv tsim kho. Nyob ntawm ntau yam qauv xws li cov tsos, kev txo cov dej muaj peev xwm, muaj pes tsawg leeg, thiab cov khoom siv tshuaj, cov dej reducers tuaj yeem muab faib ua ntau hom. Cov dej reducers pab txo cov cement thiab dej xav tau, txhim kho cov yas yas, thiab txo cov pob zeb ua pob. Cov txheej txheem ntawm cov dej reducers muaj xws li dispersion, lubrication, steric hindrance, thiab tswj-tso los. Muaj ntau ntau formulations rau dej reducers. Hauv qab no yog ob qho piv txwv formulations rau siv.

1. Dab tsi yog qhov dej txo qis?

Cov dej reducer yog ib qho khoom ntxiv uas txo cov dej sib xyaw hauv cov pob zeb tsis hloov qhov poob qis. Feem ntau cov dej reducers yog anionic surfactants, suav nrog lignosulfonates, naphthalene sulfonate formaldehyde polymers, thiab lwm yam. Thaum ntxiv rau cov pob zeb sib xyaw, lawv cuam tshuam cov cement hais, txhim kho kev ua haujlwm, txo cov dej-rau-cement piv, thiab txhim kho cov dej ntws ntawm cov pob zeb sib tov. Xwb, lawv tuaj yeem txo cov cement siv, yog li txuag cov cement.

2. Hom dej txo qis

• Los ntawm qhov tshwm sim:Cov dej reducers tuaj yeem faib ua kua lossis hmoov. Cov ntaub ntawv ua kua feem ntau muaj cov ntsiab lus ntawm 20%, 40% (hu ua niam cawv), lossis 60%, thaum cov ntaub ntawv hmoov feem ntau muaj 98% cov ntsiab lus.
• Los ntawm Kev Txo Dej thiab Txhim Kho Kev Muaj Peev Xwm:Ordinary Water Reducers (tseem hu ua plasticizers, nrog cov dej txo qis qis dua 8%, xws li lignosulfonate-based) ).High-efficiency Water Reducers (tseem hu ua superplasticizers, nrog rau cov dej txo qis qis dua 14. %, suav nrog naphthalene-based, melamine-based, amino sulfonate-based, thiab aliphatic-based hom). (nrog rau tus nqi txo dej tsis pub tsawg tshaj 25%, xws li polycarboxylate-raws li dej reducers), ntxiv categorized rau thaum ntxov-lub zog hom, hom qauv, thiab hom retarded.
• Los ntawm cov khoom sib xyaw:Lignosulfonate-based, polycyclic aromatic ntsev-raws li, dej-soluble resin sulfonate-raws li, naphthalene-based high-efficiency water reducers, aliphatic-based high-efficiency water reducers, amino-based high-efficiency water reducers, thiab polycarboxylate-based siab - Kev ua haujlwm dej reducers.
• Los ntawm Chemical Composition:Lignosulfonate-based, naphthalene-based, melamine-based, amino sulfonate-based, fatty acid-based, thiab polycarboxylate-based high-efficiency dej reducers.

3. Kev ua haujlwm ntawm cov dej txo qis

• Tsis muaj kev hloov pauv ntawm lwm cov khoom siv raw (tshwj tsis yog cov cement), cov dej txo qis tuaj yeem txo cov cement siv. Ntxiv cov dej txo qis ntawm 0.2%-0.5% ntawm cov cement loj tuaj yeem txuag tau 15%-30% ntawm cov cement noj.
• Yog tias tsis muaj kev hloov pauv ntawm lwm cov ntaub ntawv raw (tshwj tsis yog dej), cov dej txo qis tuaj yeem txo cov dej, txhim kho cov pob zeb ua kom muaj zog. Thaum ntxov thiab tom qab lub zog ntawm cov pob zeb nrog cov dej txo qis tuaj yeem nce ntau dua 60% thiab 20%, feem, piv rau cov pob zeb tsis muaj dej txo. Qhov no tso cai rau lub ncuav ntawm cov pob zeb muaj zog nrog C100 qib.
• Tsis muaj kev hloov pauv ntawm lwm cov khoom siv raw, cov dej reducers tuaj yeem txhim kho cov khoom siv rheological thiab plasticity ntawm cov pob zeb, ua kom muaj kev tsim kho los ntawm nws tus kheej ntws, siv dej, thiab kev co tsis muaj kev vibration, yog li txhim kho kev tsim kho thiab txo kev siv zog.
• Ntxiv cov dej ua kom muaj txiaj ntsig zoo tuaj yeem ua ob npaug ntawm kev ua haujlwm ntawm cov pob zeb, txuas rau lub neej ib txwm muaj ntawm cov tsev.
• Cov dej reducers txo qhov shrinkage ntawm cov pob zeb thaum lub sij hawm solidification, tiv thaiv cov kab nrib pleb hauv cov khoom ua vaj tse, thiab txhim kho khov-thaw, uas yog qhov zoo rau kev tsim kho lub caij ntuj no.

4. Mechanisms ntawm cov dej reducers

• Dispersion nyhuv:Thaum cov cement sib tov nrog dej, cov txheej txheem hydration ntawm cov cement particles tsim cov txheej txheem hluav taws xob ob npaug rau ntawm qhov chaw, tsim kom muaj cov yeeb yaj kiab dej solvated thiab ua rau muaj zog txaus nyiam ntawm cov khoom. Qhov no ua rau flocculation, ntxiab 10% -30% ntawm cov dej sib tov thiab tiv thaiv nws los ntawm kev koom nrog hauv cov dej ntws dawb thiab lubrication, yog li cuam tshuam cov flowability ntawm qhov sib tov. Thaum cov dej reducer ntxiv, nws cov molecules adsorb rau cov cement hais qhov chaw, ua rau cov khoom nqa tib yam nqi (feem ntau tsis zoo), uas ua rau electrostatic repulsion uas disperses cov cement hais, tawg cov qauv flocculent thiab tso cov dej daig, uas koom nrog hauv kev ntws, yog li txhim kho cov flowability ntawm cov pob zeb sib tov.
• Lubrication nyhuv:Cov pab pawg hydrophilic nyob rau hauv cov dej reducer yog cov polar heev, thiab cov yeeb yaj kiab adsorbed ntawm cov cement particles 'qhov chaw cuam tshuam nrog cov dej molecules los tsim cov yeeb yaj kiab dej ruaj khov. Cov yeeb yaj kiab no muaj cov khoom zoo heev lubrication, txo cov zawv zawg tiv thaiv ntawm cov cement hais thiab ntxiv txhim kho cov flowability ntawm cov pob zeb.
• Cov nyhuv Steric Hindrance:Cov qauv dej reducer muaj hydrophilic sab chains uas txuas mus rau hauv cov kua dej, tsim cov txheej txheem hydrophilic adsorption ntawm qee qhov tuab ntawm cov cement hais qhov chaw. Thaum cov cement particles mus txog, cov txheej adsorption pib sib tshooj. Qhov sib tshooj ntau dua, qhov muaj zog ntau dua qhov steric hindrance, uas ua rau kom lub zog quab yuam ntawm cov khoom thiab cuam tshuam lawv cov aggregation, tswj kom muaj kev poob zoo rau cov pob zeb sib tov.
• Tswj-tso tawm nyhuv ntawm Copolymer ceg:Hom tshiab ntawm cov dej reducers, xws li polycarboxylate-raws li sawv daws yuav, koom nrog sab ceg mus rau molecules thaum lub sij hawm tsim khoom. Cov ceg no muab steric hindrance thiab yuav maj mam cleaved nyob rau hauv lub siab alkalinity ntawm cement hydration. Qhov no tso tawm carboxyl acids uas txhim khu cov nyhuv dispersion, ntxiv txhim kho cov dispersion ntawm cement hais thiab tswj qhov poob ntawm slump.

5. Cov qauv dej txo qis

Polycarboxylate Water Reducer Formula:Maleic anhydride: Acrylate poly (ethylene glycol) monoester: Sodium acrylate=1: 3: 2.4. Cov txheej txheem ntws: Siv 1% K2S2O8 ua tus pib, cov tshuaj tiv thaiv kub 85 degree, lub sijhawm tshuaj tiv thaiv 6 teev.

Formula:

Acrylic acid 38kg + txheej txheem dej 82kg

Mercaptoacetic acid 1.2kg + txheej txheem dej 138.2kg

Hydrogen peroxide 3kg + txheej txheem dej 117kg

TPEG (loj monomer) 360kg + txheej txheem dej 260kg Txheej txheem ntws: Dissolve TPEG thiab do tusyees, ua kom qhov kub ntawm 70 degree. Ntxiv cov tshuaj acrylic acid thiab cov tshuaj hydrogen peroxide los ntawm lub tank siab hauv 3 teev. Ntxiv mercaptoacetic acid tov nyob rau hauv 3.5 teev. Khaws cov tshuaj tiv thaiv ntawm 40 degree rau 3 teev kom tiav cov tshuaj tiv thaiv thiab tom qab ntawd txias rau 40 degree kom tau txais cov khoom tiav.