Cov khoom siv pob zeb yooj yim qhia kev paub!
Oct 25, 2024
I. Qhob
Txhais:
Pob zeb yog cov khoom siv pob zeb tsim los ntawm cov neeg ua haujlwm cementing, ntxhib thiab nplua aggregates, thiab dej, sib tov rau hauv ib qho kev faib ua feem, tsim los ntawm kev nplawm, compacting, thiab kho. Feem ntau, pob zeb hais txog cov cement pob zeb.
Cov pob zeb sib xyaw ua ke yog tsim los ntawm cov cement, aggregates, dej, thiab xaiv tau ntxiv admixtures thiab ntxhia additives, proportioned thiab tov nyob rau hauv ib tug batching cog, ces muag thiab thauj los ntawm lub pob zeb tov tsheb thauj mus rau qhov chaw tsim kho nyob rau hauv ib lub sij hawm.
2.Composition:
Cov khoom muaj xws li cov khoom siv cementing, coarse thiab nplua aggregates, thiab dej, nrog rau kev xaiv ntawm additives los yog additives.
- Cov khoom siv cementing:Kev khi xoob xoob rau hauv cov khoom hnyav, xws li cov cement, gypsum, lossis asphalt.
- Coarse thiab Fine Aggregates:Muab cov qauv kev txhawb nqa. Coarse aggregates muaj xws li pob zeb crushed, gravel, thiab pebbles; Cov xuab zeb zoo suav nrog dej xuab zeb, hiav txwv xuab zeb, roob xuab zeb, thiab cov xuab zeb dag.
- Dej:Feem ntau kais dej, yuav tsum ua kom tau raws li "Cov Qauv rau Cov Dej Siv Hauv Kev Sib Tw" (JGJ63).
- Admixtures thiab Additives:Txhim kho pob zeb ua haujlwm thiab txuag cov ntaub ntawv; cov khoom sib xyaw ua ke muaj xws li dej reducers, retarders, thiab expanders; Feem ntau cov additives muaj xws li ya tshauv, slag, thiab silica fume.
Kev faib tawm:
Lub pob zeb tuaj yeem faib ua ob hom: pob zeb zoo tib yam (cement pob zeb) thiab cov pob zeb tshwj xeeb (xws li pob zeb tsis muaj dej, cov pob zeb kub-resistant, hydraulic pob zeb).
Ntau yam khoom ntawm pob zeb:
Ua haujlwm tau:Qhov taw qhia tseem ceeb ntawm kev ua vaj tse kev tsim kho, feem ntau ntsuas los ntawm kev poob qis lossis kev ua haujlwm. Kev ua haujlwm zoo dua txhais tau tias yooj yim compaction thiab zoo dua zaum kawg pob zeb zoo.
Slump:Qhia qhov kev poob dawb ntawm cov pob zeb nyob rau hauv cov kev sim tshwj xeeb. Ib qho kev poob siab dua qhia tau tias muaj kev ntws zoo dua, nrog rau cov kev xav tau rau cov pob zeb ua pob zeb yog qhov tshwj xeeb siab. Slump yog ntsuas hauv mm, raug rau 5mm. Cov nqi poob qis rau cov khoom sib xyaw ua ke ntawm 80 txog 220mm.
Ntshav:Hais txog kev sib cais dej thaum lub sijhawm thauj mus los thiab nchuav, uas tuaj yeem cuam tshuam rau cov pob zeb zoo thiab lub zog.
Kev tuav dej:Kev tuav dej zoo sib xws rau cov ntshav tsis zoo.
Kev cais tawm:Qhia txog kev sib cais ntawm cov khoom sib xyaw hauv cov pob zeb sib xyaw thaum lub sijhawm thauj mus los thiab nchuav, cuam tshuam tsis zoo rau homogeneity thiab lub zog.
Cohesion:Tawm tsam kev cais.
Lub zog:Xws li compressive zog, tensile zog, thiab flexural lub zog, nrog compressive lub zog yog thawj qhov taw qhia, ntsuas nyob rau hauv MPa thiab cais raws li C10, C30, C35, mus txog C60, thiab lwm yam. High-strength pob zeb yog txhais raws li muaj ib tug muaj zog chav kawm ntawv ntawm Greater. tshaj los yog sib npaug C60.
Impermeability:Hais txog pob zeb muaj peev xwm tiv taus dej thiab roj siab, ntsuas los ntawm qib impermeability xws li P6, P8, P10, thiab P12.
Lwm yam khoom muaj xws li khov tiv thaiv, shrinkage, thiab creep, uas tsis muaj nyob ntawm no.
II. Cement
Txhais:
Cement yog cov khoom siv hydraulic feem ntau siv. Thaum sib tov nrog dej, nws tsim cov yas muab tshuaj txhuam uas tawv tawv hauv huab cua thiab dej.
Kev faib tawm:
Rau hom cement xws li Portland cement (P.Ⅰ, P.Ⅱ), zoo tib yam Portland cement (PO), volcanic tshauv Portland cement (PP), slag Portland cement (PS), ya tshauv Portland cement (PF), thiab Composite Portland cement (PC). Peb lub tuam txhab feem ntau siv Portland cement thiab zoo tib yam Portland cement.
Portland Cement:Muab faib ua P.Ⅰ (tsis muaj cov khoom sib xyaw) thiab P.Ⅱ (txog li 5% limestone lossis granulated blast furnace slag). Cov qib muaj zog muaj xws li 42.5, 42.5R, 52.5, 52.5R, 62.5, thiab 62.5R.
Ordinary Portland Cement:Tsim los ua PO, nrog qib zog ntawm 42.5, 42.5R, 52.5, thiab 52.5R.
Cement Properties:
Qib Qib thiab Lub Zog:Lub zog yog qhov taw qhia tseem ceeb rau kev txiav txim siab qib cement, raws li 28- hnub lub zog.
Cement Mortar Strength:Ntsuas los ntawm flexural thiab compressive zog.
Standard Consistency Water Requirement:Qhia txog kev xav tau dej cement, tseem ceeb heev rau lub sijhawm teem sijhawm thiab kev ntsuas kev ruaj ntseg.
Teem sijhawm:Muaj feem xyuam rau kev tsim kho; Qhov kev teeb tsa thawj zaug yuav tsum tsis pub tsawg dua 45 feeb, thiab qhov chaw zaum kawg yuav tsum tsis pub tshaj 10 teev.
Kev ruaj ntseg:Hais txog kev hloov pauv ntim tsis sib xws thaum lub sij hawm hardening, qhov taw qhia tseem ceeb ntawm qhov zoo; tsis ruaj tsis khov cement yog txwv tsis pub.
Lwm yam khoom muaj xws li fineness, lub ntiajteb txawj nqus, thiab flowability ntawm cement mortar.
Raws li cov kev qhia tshwj xeeb, cov cement tuaj yeem muab faib ua cov khoom tsim nyog thiab tsis tsim nyog.
Cov khoom tsim nyog:Ua tau raws li lub teb chaws tus qauv GB175-2007.
Cov khoom tsis tsim nyog:suav nrog txhua yam uas ua tsis tau raws li cov qauv rau kev ua kom zoo, teeb tsa lub sijhawm, cov khoom seem tsis txaus ntseeg, ruaj khov, thiab lwm yam.
Cement Cia:
Khaws cov cement los ntawm hom, qib, thiab hnub tsim khoom nrog cov ntawv qhia meej kom ntseeg tau tias kev siv thawj zaug hauv thawj zaug, tiv thaiv kev sib xyaw.
Cement yuav tsum tsis txhob muab khaws cia rau lub sijhawm ntev kom tsis txhob tawv; Feem ntau, cov cement uas khaws cia rau hauv ib txwm muaj poob 10-20% lub zog tom qab peb lub hlis. Cov cement tas (tshaj peb lub hlis ntawm kev tsim khoom) yuav tsum tau sim ua ntej siv.
III. Aggregates
(A) Aggregates, tseem hu ua aggregates, yog ib qho ntawm cov khoom tseem ceeb hauv cov pob zeb, ua haujlwm raws li lub hauv paus.
(B) Kev faib tawm: Coarse aggregates muaj qhov loj me dua 5 hli, thaum cov khoom sib xyaw zoo hauv qab 5 hli.
Fine Aggregates:
(1) Classification:
Los ntawm qhov chaw: hiav txwv xuab zeb, dej xuab zeb, roob xuab zeb.
Los ntawm fineness modulus: ntxhib, nruab nrab, nplua, thiab ultra-zoo xuab zeb.
(2) Technical Requirements for Sand in Concrete:
Particle grading yuav tsum ua tau raws li cov qauv kev cai.
Cov ntsiab lus av nkos: Xuab zeb siv rau C30 thiab siab dua yuav tsum tsis pub tshaj 3% av nkos cov ntsiab lus, vim nws cuam tshuam rau kev ua vaj tse, tshwj xeeb tshaj yog rau cov pob zeb muaj zog.
Cov ntsiab lus tsis zoo: mica, organic teeb meem.
Qhov ceev thiab lub zog.
Coarse Aggregates:
(1) Classification:
Los ntawm qhov chaw: pebbles thiab crushed pob zeb.
Los ntawm specifications: ib qho particle grading thiab nruam grading.
(2) Technical Requirements rau Pob zeb hauv pob zeb:
Particle grading yuav tsum ua tau raws li cov qauv kev cai.
Cov ntsiab lus ntawm koob zoo li thiab flaky hais yuav tsum tsis pub tshaj 15% rau pob zeb saum C30.
Cov ntsiab lus av nkos: yuav tsum tsis pub tshaj 1% rau pob zeb saum C60.
Lub zog: Yuav tsum tshaj lub zog ntawm cov pob zeb, feem ntau qhia los ntawm cubic compressive zog thiab crushing Performance index.
(3) Kev ceev faj:
Tswj cov ntsiab lus ntawm rab koob zoo li thiab flaky hais, vim lawv cuam tshuam rau kev ua haujlwm thiab lub zog.
Tsis txhob muaj av nkos, pob zeb hmoov, thiab impurities nyob rau hauv crushed pob zeb. Khaws cais los ntawm keeb kwm, hom, thiab specification.
IV. Cov khoom xyaw
Txhais:
Admixtures yog cov khoom siv ntxiv hauv cov nyiaj tsis tshaj 5% ntawm cov cement hnyav, uas tuaj yeem hloov kho cov khoom vaj khoom tsev raws li xav tau.
Kev faib tawm:
Dej-txo cov neeg ua haujlwm (ib txwm ua thiab ua haujlwm siab): Txo cov dej siv, txhim kho pob zeb ua kom muaj zog lossis ua haujlwm tau zoo.
Air-entraining agents: Ua kom huab cua cov ntsiab lus, txo cov ntshav thiab cais tawm, thiab txhim kho kev ua haujlwm.
Teem-controlling agents (retarders, accelerators, instant set): Kho lub sij hawm.
Waterproofing thiab antifreeze agents.
Expanding agents: Ua kom ntim, txhim kho impermeability.
Ntau hom admixtures muaj qhov sib txawv thiab kev siv.
Cov ntsiab lus siv:
Qhov ntau npaum li cas ntawm cov khoom sib xyaw yog qhia raws li feem pua ntawm cov cement hnyav thiab yuav tsum tau tswj nruj me ntsis; Kev noj tshuaj tsis raug tuaj yeem cuam tshuam qhov ua tau zoo.
Kev sib xyaw ua ke ntawm cov khoom sib xyaw thiab cov cement yuav tsum tau sim ua ntej siv kom ntseeg tau tias tsim nyog.
Admixtures yuav tsum tau khaws cia nrog cov ntawv qhia meej.
