Vim li cas wollastonite pob zeb tawg yooj yim?
Aug 19, 2024Tso lus
Hauv kev tsim kho engineering tiag tiag, silica fume qhob feem ntau suav hais tias yog "kuj yooj yim rau tawg". Ntawm lawv, ib feem ntawm qhov laj thawj yog qhov tsis muaj kev nkag siab ntawm cov yam ntxwv ntawm silica fume qhob, kev tsim kho kev tswj tsis tau raug kho raws li, xws li kev tswj xyuas kev tswj tsis zoo txaus. Ib feem ntawm qhov laj thawj yog tias silica fume feem ntau siv rau pob zeb nrog kev ua haujlwm siab, xws li lub zog siab, tsis muaj permeability, siab durability, thiab lwm yam. Hauv hom pob zeb no, qhov sib piv ntawm cov dej-binder yog tsawg thiab cov khoom siv cementing loj. Self-shrinkage thiab kub nce tuaj yeem ua rau kom muaj kev sib tsoo rhiab heev, thiab silica tshauv yuav ua rau kom tus kheej poob thaum ntxov. Zuag qhia tag nrho thaum ntxov tawg rhiab heev yog qhov tseeb kuj loj nyob rau hauv lub xeev constrained. Kev cuam tshuam ntawm silica fume ntawm cov pob zeb tawg, feem ntau ntawm cov kab nrib pleb thaum ntxov (tso tshwm hauv thawj ob lub lis piam), yuav tsum tau muab faib ua peb yam ntawm cov yas shrinkage, nws tus kheej shrinkage thiab kub.
1, yas shrinkage tawg
Thaum tus nqi ntawm cov dej poob (evaporation) siab tshaj tus nqi ntawm cov dej sab hauv tsiv mus rau saum npoo (los ntshav), cov yas shrinkage yuav tshwm sim. Cov ntshav ntawm wollastonite pob zeb yog me me heev. Yog tias tsis muaj kev tiv thaiv los ntshav, cov dej evaporation ntawm qhov chaw yuav ncaj qha ua rau cov yas shrinkage, thiab qhov ua tau ntawm cov yas shrinkage yuav nce. Yog li ntawd, rau cov tshiab silica pob zeb, tshwj xeeb tshaj yog thaum lub pob zeb nyob rau hauv qhuav, windy ib puag ncig tej yam kev mob, kev ntsuas yuav tsum tau nruj me ntsis txwv tsis pub nto ya raws. Ua ib txoj haujlwm zoo ntawm kev kho, silica fume qhob tuaj yeem zam tag nrho cov yas shrinkage tawg. Qhov tseem ceeb ntawm kev kho ntawm silica fume qhob tsis txhais hais tias txoj kev kho yog txawv, txhua txoj kev kho ntawm cov pob zeb zoo tib yam muaj feem xyuam rau silica fume qhob, thiab kev txhim khu kev qha thiab kev lag luam curing yuav tsum tau txais raws li ib puag ncig thiab cov yam ntxwv ntawm cov qauv. ntawm qhov project site. Qhov tseem ceeb yog pib kho los ntawm lub sijhawm ntxov tshaj plaws kom tsis txhob poob dej los ntawm qhov chaw ntawm cov pob zeb. Khaws qhov chaw tawm ntawm cov pob zeb ntub dej tom qab qhov kawg solidification, thiab tiv thaiv kom tsis txhob ya raws tsawg kawg 3 hnub.
2. Tus kheej shrinking tawg
Rau cov tsoos high water-cement ratio (ntau dua 0.42), tsis tshua muaj zog pob zeb, nws tus kheej shrinkage yog me me, yog li nws tsis nyiam tib neeg lub siab, feem ntau tsis txawv ntawm qhuav shrinkage. Txawm li cas los xij, nrog kev nce ntawm cov pob zeb ua kom muaj zog, qhov txo qis ntawm cov dej-cement (kua nplaum) piv thiab siv cov khoom siv ultrafine ntxhia, tshwj xeeb tshaj yog silica fume, tus kheej-shrinkage nce, thiab kev cuam tshuam ntawm cov kab nrib pleb thaum ntxov ua ntau dua thiab tseem ceeb. Thaum cov dej-binder piv yog 0.30, tus kheej-shrinkage ntawm pob zeb yuav ncav cuag li ib nrab ntawm tag nrho cov shrinkage. Lub zog ntawm tus kheej shrinkage: tom qab cov cement hydration, qhov ntim ntawm cov tshuaj tiv thaiv cov khoom yog tsawg dua qhov ntim ntawm cov reactant, ua rau cov tshuaj shrinkage ua ntej cov cement slurry coagulates, tshuaj shrinkage ua rau cov yas slurry shrinkage tag nrho, tsis muaj kev cuam tshuam. cov qauv sab hauv; Tom qab cov cement slurry condenses, cov tshuaj shrinkage tawm pores nyob rau hauv lub slurry lub cev, nyob rau hauv lub mob uas tsis muaj dej pauv nrog lub ntiaj teb sab nraud, cov cement hydration txuas ntxiv thiab noj cov dej hauv qhov pores, kom cov capillary drying shrinks vim. qhov txo qis hauv vapor siab nyob rau hauv lub qhov hws, ua rau cov tsos ntawm qhov ntim contraction, uas txawv ntawm qhov ziab los ntawm dej evaporation yog hu ua self-drying, thiab qhov tshwm sim. contraction yog tus kheej-tsim contraction. Self-contraction luv luv. Qhov xwm txheej ntawm autogenous shrinkage ntawm pob zeb yog tias tsis muaj dej pauv nrog lub ntiaj teb sab nraud, yog li nws feem ntau tshwm sim hauv cov pob zeb nrog cov ntim loj thiab cov dej-binder ratio. Ntxiv nrog rau cov cement, qhov ntau dua qhov kev ua ntawm cov ntxhia sib xyaw, qhov ntau dua qhov nws tus kheej shrinkage ntawm pob zeb hauv tib lub sijhawm. Tus kheej-shrinkage ntawm lub zog siab silica fume pob zeb tuaj yeem ncav cuag 200 ~ 300x 10-6. Tab sis ntawm qhov tod tes. Tsis tas li ntawd, wollastonite tuaj yeem txhim kho lub zog tensile thaum ntxov ntawm cov pob zeb, ua kom cov creep ntxov, thiab inhibit qhov tawg thaum ntxov, uas yog, wollastonite tuaj yeem "nce" thiab "txo" txoj kev pheej hmoo ntawm kev tawg thaum ntxov. Feem ntau hais lus, cov ntsiab lus ntawm wollastonite tsis pub tshaj 5% ntawm cov khoom siv cementing, uas tsis muaj kev cuam tshuam rau kev tawg thaum ntxov ntawm pob zeb. Thaum qhov ntau npaum li cas ntawm 5 ~ 10%, silica fume tuaj yeem ua rau muaj kev cuam tshuam ntawm kev tawg thaum ntxov. Qhov sib ntxiv ntawm ntau tshaj 10% yuav twv yuav ua rau kom tawg rhiab heev.
3, qhov cuam tshuam rau pob zeb kub nce
Silica fume tsis ua kom cov dej kub ntawm cov khoom siv cementing, tab sis ua kom cov hydration ntawm cov cement thiab ua rau cov dej kub tso tawm ua ntej. Nyob rau tib lub zog, kev siv cov silica fume tuaj yeem txo cov cement ntau, pab npaj cov pob zeb tsis zoo los yog cov pob zeb tsis zoo, txo qhov kub thiab txias thiab tawg rhiab heev. Feem ntau, cov nyhuv ntawm silica fume ntawm lub tshav kub ntawm hydration tuaj yeem tsis quav ntsej thaum qhov ntau npaum li cas tsawg dua 10%.
Cov saum toj no yog vim li cas qhov tawg ntawm wollastonite pob zeb yog ib qho yooj yim los soj ntsuam. Rau siab zog, hnav-resistant, underwater poured anti-erosion pob zeb, thiab lwm yam., cov ntsiab lus ntawm wollastonite yuav tsum tsis txhob tsawg dhau, feem ntau yog accounting rau 6% mus rau 12% ntawm cov cementized khoom. Nyob rau lub sijhawm no, kev tswj hwm ntawm cov kab nrib pleb thaum ntxov hauv cov qauv yuav tsum pib los ntawm kev txo qis ntawm kev txwv (tsawg dua 50%) thiab txo qhov kub ntawm cov pob zeb (qhov kub siab tshaj plaws ntawm cov pob zeb tsis tshaj 40oC), lossis kev siv. ntawm siab modulus fiber ntau tawg kuj (xws li ultra-siab ua tau zoo pob zeb UHPC), los yog siv cov expansion agents (AC los yog C hom) los them rau shrinkage.
