Hnub Kawg:9,Jan,2023

Dab tsi yog dej reducers?

Cov dej txo qis (xws li Lignosulfonates) yog ib hom kev sib xyaw uas tau ntxiv rau cov pob zeb thaum lub sijhawm sib xyaw. Cov dej reducers tuaj yeem txo cov dej ntsiab lus los ntawm 12-30% yam tsis muaj kev cuam tshuam kev ua haujlwm ntawm cov pob zeb lossis cov khoom siv dag zog ntawm cov pob zeb (uas peb feem ntau hais txog lub zog compressive). Muaj lwm cov ntsiab lus rau Dej reducers, uas yog Superplasticizers, plasticizers lossis high-range water reducers (HRWR).

Hom dej-txo Admixtures

Muaj ntau hom dej-txo admixtures. Cov tuam txhab tsim khoom muab cov npe sib txawv thiab kev faib tawm rau cov khoom sib xyaw xws li dej-proofers, densifiers, workability aids, thiab lwm yam.

Feem ntau, peb tuaj yeem categorizes dej-txo ua peb hom raws li lawv cov tshuaj muaj pes tsawg leeg (raws li hauv Table 1):

lignosulfonates, hydroxycarboxylic acid, thiab hydroxylated polymers.

Lignin tuaj qhov twg?

Lignin yog ib qho khoom siv nyuaj uas sawv cev kwv yees li 20% ntawm cov ntoo. Thaum lub sij hawm tus txheej txheem rau zus tau tej cov ntaub ntawv-ua pulp los ntawm ntoo, ib tug pov tseg cawv yog tsim raws li ib tug by-cov khoom uas muaj ib tug complex sib tov ntawm tshuaj, xws li decomposition khoom ntawm lignin thiab cellulose, sulfonation khoom ntawm lignin, ntau yam carbohydrates (qab zib) thiab dawb sulfurous acid los yog sulfates.

Tom qab neutralization, nag lossis daus thiab fermentation txheej txheem tsim ntau yam ntawm lignosulfonates ntawm txawv purity thiab muaj pes tsawg leeg nyob ntawm ntau yam, xws li cov neutralizing alkali, cov txheej txheem pulping siv, qib ntawm fermentation thiab txawm hom thiab hnub nyoog ntawm cov ntoo siv los ua pulp feedstock.

Lignosulfonates ua cov dej txo qis hauv pob zeb

Lignosulfonate superplasticizer koob tshuaj feem ntau yog 0.25 feem pua, uas tuaj yeem ua rau cov dej txo mus txog 9 txog 12 feem pua ​​​​hauv cov ntsiab lus cement (0.20-0.30%). Raws li siv nyob rau hauv kom zoo npaum li cas, pob zeb muaj zog txhim kho los ntawm 15-20% thaum piv rau cov ntaub ntawv siv pob zeb. Lub zog loj hlob los ntawm 20 mus rau 30 feem pua ​​​​tom qab 3 hnub, los ntawm 15-20 feem pua ​​​​tom qab 7 hnub, thiab los ntawm tib tus nqi tom qab 28 hnub.

Yog tias tsis hloov cov dej, cov pob zeb yuav ntws tau yooj yim dua, ua kom yooj yim rau kev ua haujlwm nrog (piv txwv li kev ua haujlwm ntxiv).

Los ntawm kev siv ib tonne ntawm lignosulfonate superplasticizer hmoov es tsis txhob ntawm cov cement, koj yuav txuag tau 30-40 tonnes ntawm cov cement thaum tuav cov pob zeb zoo tib yam, kev siv, thiab kev siv pob zeb.

Hauv lub xeev tus qauv, cov pob zeb sib xyaw nrog tus neeg sawv cev no tuaj yeem ncua sijhawm lub ncov kub ntawm dej los ntawm ntau tshaj tsib teev, lub sijhawm kawg ntawm kev ua vaj tse los ntawm ntau tshaj peb teev, thiab lub sijhawm teem sijhawm ntawm pob zeb ntau tshaj peb teev piv rau kev siv pob zeb. Qhov no yog qhov zoo rau kev tsim kho lub caij ntuj sov, cov khoom siv pob zeb thauj khoom, thiab cov pob zeb loj.

Lignosulfonate superplasticizer nrog micro-entraining tuaj yeem txhim kho cov pob zeb ua haujlwm ntawm kev khov-thaw impermeability.