Vim li cas thiaj tsim nyog ntxiv Silica hmoov rau pob zeb?

Vim li cas cov dej xav tau lossis viscosity nce thaum silica fume ntxiv rau pob zeb?

 

Silica fume tuaj yeem txhim kho kev ua tau zoo ntawm cov pob zeb, tab sis nws kuj ua rau cov dej xav tau thiab viscosity. Thaum siv cov khoom tsawg, silica fume tuaj yeem txhim kho cov dej ntws ntawm cov pob zeb; Txawm li cas los xij, ntawm qhov ntau dua, nws tuaj yeem ua rau muaj viscosity thiab tawg thaum ntxov. Txhawm rau tiv thaiv kev tawg, kev kho kom zoo thiab sib xyaw nrog lwm cov ntaub ntawv yog qhov tseem ceeb.

Silica fume

Kev ua tau zoo

Thaum ntxov tawg

Silica fume hais yog hydrophilic thiab muaj thaj tsam loj heev. Tus nqi ntawm cov dej yuav tsum tau ntub dej xws li thaj chaw loj saum npoo yog qhov siab. Yog li ntawd, raws li cov ntsiab lus ntawm silica fume nce (ntau dua 5%), qhov kev thov dej los yog dej-cement piv ntawm cov pob zeb sib tov yuav nce ntxiv yog tias qhov kev poob qis yuav ua tiav. Ib yam li ntawd, yog tias cov ntsiab lus ntawm cov dej los yog cov dej-cement piv tsis hloov, cov pob zeb yuav ua kom khov ntxiv thaum cov ntsiab lus silica fume nce. Txhawm rau txhim kho lub zog thiab impermeability ntawm cov pob zeb tsis muaj qhov sib piv ntawm cov dej-cement thiab kom ua tiav kev ua haujlwm zoo, silica fume feem ntau yog siv ua ke nrog cov dej-txo cov neeg ua haujlwm lossis superplasticizers. Cov silica fume pob zeb tshiab muaj kev sib raug zoo thiab tsis yooj yim rau kev sib cais.

Thaum cov ntsiab lus silica fume nyob rau hauv ib qho qis, piv txwv li, hauv 5% ntawm cov ntaub ntawv cementitious, silica fume tuaj yeem txo qhov viscosity ntawm cov pob zeb sib tov. Nyob rau hauv cov ntaub ntawv no, lub particle zoo ntawm silica fume (spherical particles) plays lub luag hauj lwm tseem ceeb, raws li cov "pob-cov kabmob" cov nyhuv ntawm spherical particles outweighs lub "wetting dej thov" cov nyhuv ntawm qhov chaw siab. Nyob rau hauv lwm yam lus, ib tug tsawg npaum li cas ntawm silica fume tsis tsuas yog tsub kom lub sib raug zoo ntawm cov pob zeb sib tov, tab sis kuj txhim kho nws flowability thiab txo cov twj tso kua mis, ua rau nws heev haum rau npaj high-workability los yog nws tus kheej-compacting pob zeb.

Vim li cas silica fume pob zeb yuav tawg yooj yim?

Hauv kev siv tswv yim, silica fume qhob feem ntau suav hais tias "yuav ua rau tawg." Ib feem ntawm qhov laj thawj yog kev nkag siab tsis txaus ntawm cov yam ntxwv ntawm silica fume qhob, thiab tsis muaj kev hloov kho hauv kev tsim kho kom zoo, xws li kev tswj tsis txaus ntawm kev kho kom zoo. Lwm qhov laj thawj yog vim li cas silica fume feem ntau yog siv rau hauv cov pob zeb uas xav tau kev ua haujlwm siab, xws li lub zog siab, tsis tshua muaj permeability, thiab siab ntev. Hom pob zeb no muaj qhov sib piv ntawm cov dej-cement tsawg thiab cov khoom siv cementitious ntau, uas tuaj yeem ua rau muaj kev nkag siab ntau ntxiv rau qhov shrinkage thiab kub nce, uas yuav ua rau tawg. Ntxiv mus, silica fume tsub kom lub hnub nyoog thaum ntxov autogenous shrinkage, ua rau cov pob zeb ua rau cov kab nrib pleb thaum ntxov nyob rau hauv kev txwv. Kev cuam tshuam ntawm silica fume ntawm cov pob zeb tawg yog feem ntau cuam tshuam rau cov kab nrib pleb thaum ntxov (tshwm sim hauv thawj ob lub lis piam) thiab yuav tsum tau soj ntsuam los ntawm kev xav ntawm cov yas shrinkage, autogenous shrinkage, thiab kub los.