Hnub Kawg: Lub Plaub Hlis 1, 2024
Nws feem ntau ntseeg tias qhov kub thiab txias, qhov ntau cov cement hais yuav adsorb polycarboxylate dej-txo tus neeg sawv cev. Nyob rau tib lub sijhawm, qhov kub siab dua, qhov pom tseeb dua cov khoom siv cement hydration yuav haus cov polycarboxylate dej-txo tus neeg sawv cev. Raws li kev sib xyaw ua ke ntawm ob qhov cuam tshuam, raws li qhov kub thiab txias nce, qhov fluidity ntawm pob zeb ua phem zuj zus. Qhov kev txiav txim siab no tuaj yeem piav qhia tau zoo txog qhov tshwm sim uas qhov fluidity ntawm pob zeb nce ntxiv thaum qhov kub thiab txias poob qis, thiab qhov poob qis ntawm cov pob zeb nce thaum qhov kub nce. Txawm li cas los xij, thaum lub sij hawm tsim kho, nws tau pom tias qhov fluidity ntawm pob zeb yog qhov tsis zoo ntawm qhov kub thiab txias, thiab thaum qhov kub ntawm cov dej sib tov yog nce, qhov fluidity ntawm cov pob zeb tom qab lub tshuab yog nce. Qhov no tsis tuaj yeem piav qhia los ntawm cov lus xaus saum toj no. Txog rau qhov kawg no, kev sim tau ua los tshuaj xyuas, tshawb xyuas cov laj thawj ntawm qhov tsis sib xws, thiab muab qhov ntsuas kub kom tsim nyog rau kev ua vaj tse.
Txhawm rau kawm txog cov txiaj ntsig ntawm kev sib xyaw dej kub ntawm cov nyhuv dispersion ntawm polycarboxylate dej-txo tus neeg sawv cev. Cov dej ntawm 0 ° C, 10 ° C, 20 ° C, 30 ° C, thiab 40 ° C tau npaj raws li kev sim rau cement-superplasticizer compatibility test.
Kev soj ntsuam qhia tau hais tias thaum lub sij hawm tawm ntawm lub tshuab yog luv luv, qhov kev nthuav dav ntawm cov cement slurry thawj zaug nce thiab tom qab ntawd txo qis thaum kub nce. Yog vim li cas rau qhov tshwm sim yog tias qhov kub thiab txias cuam tshuam rau ob qho tib si cement hydration tus nqi thiab tus nqi adsorption ntawm superplasticizer. Thaum qhov kub thiab txias, qhov nrawm dua qhov adsorption ntawm superplasticizer molecules yog, qhov zoo dua qhov cuam tshuam thaum ntxov. Nyob rau tib lub sijhawm, hydration tus nqi ntawm cov cement accelerates, thiab kev noj cov dej txo tus neeg sawv cev los ntawm cov khoom hydration nce, uas txo cov fluidity. Thawj qhov nthuav dav ntawm cement paste yog cuam tshuam los ntawm kev sib xyaw ua ke ntawm ob yam no.
Thaum qhov sib tov dej kub yog ≤10 ° C, tus nqi adsorption ntawm superplasticizer thiab cov cement hydration tus nqi yog ob qho tib si me me. Ntawm lawv, qhov adsorption ntawm dej-txo tus neeg sawv cev ntawm cov cement hais yog qhov tswj tau. Txij li thaum lub adsorption ntawm dej-txo tus neeg saib xyuas ntawm cov cement hais qeeb qeeb thaum qhov kub thiab txias, qhov pib dej-txo tus nqi qis, uas yog manifested nyob rau hauv qis pib fluidity ntawm cement slurry.
Thaum qhov kub ntawm cov dej sib tov yog nruab nrab ntawm 20 thiab 30 ° C, tus nqi adsorption ntawm cov dej-txo tus neeg sawv cev thiab cov hydration tus nqi ntawm cov cement nce nyob rau tib lub sij hawm, thiab tus nqi adsorption ntawm cov dej-txo cov tshuaj molecules nce ntxiv. obviously, uas yog reflected nyob rau hauv nce nyob rau hauv thawj fluidity ntawm cov cement slurry. Thaum cov dej sib tov kub yog ≥40 ° C, cov cement hydration tus nqi nce ntxiv thiab maj mam dhau los ua qhov tseem ceeb. Yog li ntawd, tus nqi adsorption net ntawm cov dej-txo tus neeg sawv cev molecules (adsorption tus nqi rho tawm tus nqi noj) txo qis, thiab cov cement slurry kuj qhia tias txo cov dej tsis txaus. Yog li ntawd, nws ntseeg tau hais tias qhov pib tawg ntawm cov dej txo tus neeg sawv cev yog qhov zoo tshaj plaws thaum cov dej sib tov yog nruab nrab ntawm 20 thiab 30 ° C thiab cov cement slurry kub ntawm 18 txog 22 ° C.
Thaum lub sij hawm tawm ntawm lub tshuab ntev, cov cement slurry expansion yog raws li qhov feem ntau lees txais. Thaum lub sijhawm txaus, tus neeg saib xyuas dej-txo polycarboxylate tuaj yeem raug adsorbed ntawm cov cement hais ntawm txhua qhov kub kom txog thaum nws saturated. Txawm li cas los xij, ntawm qhov kub qis, tus neeg saib xyuas dej tsawg dua yog siv rau cov cement hydration. Yog li ntawd, raws li lub sij hawm mus, qhov nthuav ntawm cov cement slurry yuav nce nrog kub. Nce thiab txo.
Qhov kev sim no tsis tsuas yog txiav txim siab qhov kub thiab txias, tab sis kuj tseem them nyiaj rau cov nyhuv ntawm lub sijhawm ntawm cov nyhuv dispersion ntawm polycarboxylate dej-txo tus neeg saib xyuas, ua rau qhov kev txiav txim siab ntau dua thiab ze rau qhov tseeb engineering. Cov lus xaus kos yog raws li nram no:
(1) Ntawm qhov kub thiab txias, cov nyhuv dispersion ntawm polycarboxylate dej-txo tus neeg saib xyuas muaj qhov pom tseeb raws sijhawm. Raws li lub sij hawm sib tov nce, fluidity ntawm cov cement slurry nce. Raws li qhov kub ntawm cov dej sib tov nce, qhov nthuav dav ntawm cov cement slurry ua ntej nce thiab tom qab ntawd txo qis. Nws tuaj yeem muaj qhov sib txawv tseem ceeb ntawm lub xeev ntawm pob zeb vim nws tawm ntawm lub tshuab thiab lub xeev ntawm cov pob zeb thaum nws tau nchuav rau ntawm qhov chaw.
(2) Thaum lub sijhawm ua haujlwm kub qis, cua sov cov dej sib tov tuaj yeem pab txhim kho cov dej ntws ntawm cov pob zeb. Thaum lub sij hawm tsim kho, kev saib xyuas yuav tsum tau them rau kev tswj cov dej kub. Qhov kub ntawm cov cement slurry yog nyob nruab nrab ntawm 18 thiab 22 ° C, thiab lub fluidity yog qhov zoo tshaj plaws thaum nws tawm ntawm lub tshuab. Tiv thaiv qhov tshwm sim ntawm qhov txo qis ntawm cov pob zeb ua los ntawm cov dej kub ntau dhau.
(3) Thaum lub sij hawm tawm ntawm lub tshuab ntev, qhov nthuav dav ntawm cov cement slurry txo qis thaum kub nce.
Post lub sij hawm: Apr-01-2024
