Qhob admixture Superplasticizer uas tuaj yeem ua kom muaj zog ntawm pob zeb

Qhob admixture Superplasticizer uas tuaj yeem ua kom muaj zog ntawm pob zeb

Concrete admixtures hais txog cov khoom uas tuaj yeem txhim kho kev ua tau zoo ntawm cov pob zeb sib xyaw hauv cov txheej txheem sib xyaw ua ke. Nws cov koob tshuaj feem ntau tsis ntau tshaj 5 feem pua ​​​​ntawm cov cement loj. Vim yog kev txhim kho ntawm kev ua tau zoo ntawm pob zeb los ntawm cov khoom sib xyaw, nws daim ntawv thov hauv engineering yog nce. Hauv ntau lub tebchaws, cov pob zeb ua ke nrog cov khoom sib xyaw tau suav txog 60 feem pua ​​​​rau 90 feem pua ​​​​ntawm tag nrho cov pob zeb. Yog li ntawd, admixtures tau maj mam ua qhov kev faib ua feem ntawm pob zeb. lub thib tsib feem ntawm .

1. Kev faib tawm ntawm cov khoom sib xyaw

Muaj ntau ntau hom kev sib xyaw ua ke. Raws li "Classification, Naming thiab Definition of Concrete Admixtures", cov pob zeb sib xyaw tau muab faib ua plaub pawg raws li lawv lub luag haujlwm tseem ceeb:

1. Admixtures los txhim kho kev ua haujlwm: dej-txo cov khoom, cov twj tso kua mis, cov khoom siv cua nkag

2. Admixtures los kho qhov chaw thiab hardening lub sij hawm: retarder, thaum ntxov zog tus neeg sawv cev, accelerator

3. Admixtures los txhim kho durability: xeb inhibitors, waterproofing agents, air-entraining agents

4. Admixtures los txhim kho lwm yam khoom: huab cua-entraining agent, colorant, expansion agent, antifreeze

2. Dej reducer

Dej reducer yog hais txog qhov sib ntxiv ntawm cov khoom sib xyaw uas tuaj yeem txo cov dej siv los sib xyaw ua ke nyob rau hauv cov xwm txheej uas cov slump ntawm pob zeb yog qhov zoo ib yam.

(1) Mechanism ntawm kev ua ntawm cov dej txo tus neeg sawv cev

Cov dej reducer yog cov khoom siv saum npoo av, thiab nws cov molecule yog tsim los ntawm ob ntu: pawg hydrophilic thiab pawg hydrophobic. Thaum cov cement sib tov nrog dej, cov cement slurry tsim cov qauv flocculation, uas qhwv ib feem ntawm cov dej sib tov thiab txo cov fluidity. Lub mechanism ntawm kev txiav txim ntawm cov dej txo tus neeg sawv cev yog manifested nyob rau hauv peb yam nram qab no:

(1) Cov pab pawg hydrophobic yog directional adsorbed rau saum npoo ntawm cov cement hais, thiab cov pab pawg hydrophilic taw qhia rau cov tshuaj aqueous, kom lub ntsej muag ntawm cov cement particles muaj tib qho nqi, thiab lub zog quab yuam cais cov cement particles, tso tawm dawb. dej hauv cov qauv flocculation, thiab nce fluidity;

(2) Cov pab pawg hydrophilic absorbs ib tug loj tus naj npawb ntawm polar dej molecules, tsub kom lub thickness ntawm cov solvated dej zaj duab xis nyob rau saum npoo ntawm cement hais, ua raws li ib tug lubricant, thiab txhim kho kev ua hauj lwm;

(3) Cov dej txo tus neeg saib xyuas txo qhov nro ntawm qhov chaw, thiab cov cement hais tau yooj yim dua wetted, kom cov dej txaus txaus, yog li txhim kho lub zog ntawm cov pob zeb.

2) Technical thiab economic teebmeem ntawm cov dej txo tus neeg sawv cev

1. Ua kom muaj kuab paug. Thaum cov dej siv thiab dej-cement piv tsis hloov, cov pob zeb tawg tuaj yeem nce ntxiv los ntawm 100-200 hli yam tsis cuam tshuam rau lub zog ntawm cov pob zeb.

2. Txhim kho lub zog ntawm pob zeb. Nyob rau hauv cov xwm txheej ntawm kev ua kom lub cev muaj zog thiab cov nyiaj ntawm cov cement tsis hloov, cov dej sib xyaw tuaj yeem raug txo los ntawm 10 feem pua ​​​​mus rau 15 feem pua, yog li txo cov dej-cement piv thiab ua kom cov pob zeb muaj zog los ntawm 15 feem pua ​​​​rau 20 feem pua.

3. Txuag cov cement. Nyob rau hauv cov xwm txheej ntawm kev ua kom muaj dej thiab dej-cement piv tsis hloov, tus nqi ntawm cov cement tuaj yeem raug txo kom sib npaug thaum txo cov dej sib tov.

4. Txhim kho qhov ruaj khov ntawm pob zeb.

(3) Hom dej txo cov neeg ua haujlwm

Raws li cov tshuaj muaj pes tsawg leeg, feem ntau yog lignin series, naphthalene series, dej-soluble resins, molasses thiab composite dej txo cov neeg ua haujlwm.

1. Lignin-raws li dej reducer

Xws li calcium lignosulfonate (ntoo calcium), sodium lignosulfonate (ntoo sodium), magnesium lignosulfonate (ntoo magnesium), thiab lwm yam. Ntawm lawv, ntoo calcium superplasticizer yog dav siv.

Ntoo calcium superplasticizer yog xim av-daj hmoov tau los ntawm kev siv cov sulfite pulp pov tseg cov kua uas tshuav los ntawm kev tsim cov ntaub so ntswg los yog fiber ntau cov ntaub ntawv raw, neutralized nrog mis nyuj ntawm txiv qaub, desugared los ntawm lom fermentation, evaporated thiab concentrated, thiab tshuaj tsuag qhuav. .

Qhov tsim nyog ntawm cov ntoo calcium superplasticizer feem ntau yog {{0}}.2 feem pua ​​​​rau 0.3 feem pua ​​​​ntawm cov cement loj. Cov dej txo tus nqi yog 10 feem pua ​​​​mus rau 15 feem pua ​​​​, thiab 28d compressive zog ntawm pob zeb yog nce 10 feem pua ​​​​rau 20 feem pua; yog tias cov dej tsis txo qis, cov pob zeb tawg tuaj yeem nce los ntawm 80 mus rau 100mm; Yog hais tias lub zog compressive thiab slump ntawm cov pob zeb tau khaws cia Tsis muaj kev hloov pauv, kwv yees li 10 feem pua ​​​​ntawm cov cement noj yuav cawm tau. Ntoo calcium superplasticizer muaj cov nyhuv retarding ntawm pob zeb. Yog hais tias nws ntxiv ntau dhau los yog qhov kub thiab txias, nws cov nyhuv retarding yuav tseem ceeb dua, thiab nws kuj yuav txo tau lub zog ntawm pob zeb. Yuav tsum ceev faj thaum siv nws.

Ntoo calcium superplasticizer tuaj yeem siv rau hauv kev ua vaj tse dav dav, tshwj xeeb tshaj yog nyob rau hauv huab hwm coj pouring, plam-daim ntawv tsim, siv cov pob zeb thiab lub caij ntuj sov tsim, thiab lwm yam. Ntoo calcium superplasticizer yuav tsum tsis txhob siv ib leeg rau lub caij ntuj no kev tsim kho, thaum txhua hnub qhov kub thiab txias yog qis dua 5. degree, nws yuav tsum tau siv ua ke nrog thaum ntxov muaj zog tus neeg saib xyuas los yog antifreeze tus neeg saib xyuas. Ntoo calcium superplasticizer yuav tsum tsis txhob siv ib leeg rau chav kho pob zeb thiab cov pob zeb prestressed, kom tsis txhob xoob ntawm pob zeb nto tom qab chav kho.

2. Naphthalene sulfonate dej txo

Naphthalene-raws li dej reducer yog ua los ntawm naphthalene los yog naphthalene homologues los ntawm sulfonation thiab methanol retraction. Tam sim no, kuv lub teb chaws cov khoom tseem ceeb yog NNO, NF, FDN, UNF, MF, Jian I thiab lwm yam dej txo cov neeg ua haujlwm, feem ntau yog cov dej tsis muaj cua nkag.

Qhov tsim nyog npaum li cas ntawm naphthalene-raws li dej reducer yog 0.5 feem pua ​​​​rau 1.0 feem pua ​​​​ntawm cov cement loj, cov dej txo tus nqi yog 10 feem pua ​​​​mus rau 25 feem pua ​​​​, thiab lub zog ntawm pob zeb yog nce. los ntawm ntau tshaj 20 feem pua ​​​​tom qab 28 hnub. Naphthalene-raws li superplasticizers muaj cov dej zoo txo ​​thiab ntxiv dag zog, thiab muaj zog adaptability rau ntau hom cement. Nws yog tsim rau kev npaj thaum ntxov-lub zog, siab-lub zog, kua thiab chav-kho pob zeb.