** Ceebtoom txog cov ntsiab lus thiab kev ruaj ntseg:** Qhov no yog cov ntawv sau cia, tsis yog cov lus qhia siv tau, qhov project lossis cov lus qhia ua haujlwm. Cov duab thiab cov duab yog muab los ntawm thawj tsab xov xwm thiab yuav tsum tsis txhob muab txhais ua pov thawj los ntawm cov qauv niaj hnub no. Kev xaiv, kuaj, khaws cia thiab siv cov cement yuav tsum ua raws li cov neeg tsim khoom cov lus qhia, cov kev cai siv tau thiab tsim los ntawm tus kws tsim qauv tsim nyog. Cov duab yog piav qhia thiab tsis sawv cev rau cov haujlwm uas tau lees paub ntawm Savo Kusić.
Cement tsis yog ib feem ntawm lub tuam txhab kev nthuav tawm tshiab rau pej xeem. Lub hom phiaj ntawm kev tsim khoom tam sim no muaj ntoo qhov rais, wood-aluminium Qhov rais thiab kev cai qhov rooj. Rau ib qhov project tshwj xeeb, koj tuaj yeem xa ib thov rau cov lus hais.
General data
Cements yog hydraulic binders: tom qab sib tov nrog dej, lawv harden mus rau hauv lub pob zeb loj nyob rau lub sij hawm, ob qho tib si nyob rau hauv dej thiab nyob rau hauv huab cua. Nyob rau hauv rooj plaub thib ob, kev kho kom tiav tsuas yog ua tiav yog tias cov tshuaj khib tau khaws cia noo thaum kho, tshwj xeeb tshaj yog nyob rau thawj hnub.
Qhia meej meej thiab ntsuas qhov tawv tawv yuav tsum, txawm tias nyob nruab nrab ntawm lub caij ntuj sov, tsuas yog pib tom qab kev sib xyaw ntawm cov cement. Raws li cov qauv uas tau hais hauv thawj cov ntawv nyeem, qhov pib ntawm hardening yuav tsum pom tsis pub dhau ib teev tom qab ua cov cement slurry. Qhov kawg ntawm kev sib txuas ntawm qhov kub ntawm 18 mus rau 21 °C tshwm sim, raws li txoj cai, tsis pub dhau plaub thiab tsis pub dhau 12 teev.
Thaum ua haujlwm ntawm qhov kub thiab txias, hardening yuav tsum lag tsawg li sai tau piv rau hardening ntawm ib txwm kub, thaum nyob rau hauv high kub nws acceleration yuav tsum tau txwv.
Lub hardened cement pawg yuav tsum ruaj khov nyob rau hauv ntim. Lub zog yuav tsum tsis txhob txo qis thaum lub sijhawm vim muaj cov cement los yog kev cuam tshuam ntawm Frost, kua thiab lwm yam. Cov kab nrib pleb uas tshwm sim los ntawm shrinkage ntawm mortar thiab pob zeb tuaj yeem zam tau los ntawm kev ua haujlwm zoo thiab kev saib xyuas, thiab qhov twg cov xwm txheej no tuaj yeem ua tau raws li lub xeev ntawm cov tshuab cement.
Rau cov pob zeb ua haujlwm thiab kev tsim kho cov choj, raws li cov ntawv qub, tsuas yog siv cov cements thiab cov nqi siab aluminate cements. Nws kuj tseem tau hais tias ib tus yuav tsum siv cov cements uas nws cov khoom tsim tau nyob rau hauv kev saib xyuas ntawm cov koom haum rau kev tswj cov qauv thiab uas dais lawv cov cim lag luam. Rau lub hom phiaj tshwj xeeb, xws li kev thauj khoom hnyav hnyav, pom zoo cov cemented standardized.
Thaum nws yog ib qho tsim nyog yuav tau txais cov pob zeb zoo hauv lub sijhawm luv luv, piv txwv li thaum ua pawg, alumina cement los rau hauv kev xav. Nws muaj pes tsawg leeg sib txawv ntawm Portland cement, thiab txhuas oxide (Al₂O₃) dominates tshuaj muaj pes tsawg leeg.
- Cov duab - hmoov alumina cement.*
Tshuaj muaj pes tsawg leeg ntawm cov cement
Cov lus ntsuam xyuas ntawm cov cements coj mus muag qhia cov ntaub ntawv ntawm cov tshuaj muaj pes tsawg leeg ntawm ib tus neeg. Nws qhia tau hais tias cov ntsiab lus ntawm txiv qaub nyob rau hauv ferruginous Portland cement feem ntau qis dua nyob rau hauv classic Portland xis mas, thaum smelting cement muaj txawm tsawg txiv qaub. Dawb portland cements tau txais nrog cov ntsiab lus hlau tsawg heev.
Archive table — kev tsom xam ntawm kev lag luam cements los ntawm thawj tsab xov xwm.
Cov kev xav txog qhov tsim nyog tshaj plaws ntawm cov cement, xws li kev siv dav dav lossis kev tsim kho tshwj xeeb, feem ntau hloov thiab sib txawv. Tshuaj ntsuam xyuas ib leeg tsis muab cov ntaub ntawv tiav. Nws qhia tau hais tias cov neeg siv khoom, yog tias tsis muaj kev pom zoo tshwj xeeb, txawm tias cov qauv lossis cov xwm txheej ntxiv tau raug hwm thaum lub sijhawm tsim khoom thiab seb cov cement muaj pes tsawg leeg nyob rau hauv cov kev txwv ib txwm muaj lossis sib txawv ntawm lawv.
Pib thiab xaus ntawm kev khi
Yog tias qhov kev teeb tsa ntawm cov cement pib ua ntej cov pob zeb tso, nws tuaj yeem cuam tshuam rau kev txhim kho lub zog ntawm cov cement thiab pob zeb nws tus kheej. Txhawm rau kom tsis txhob muaj cov xwm txheej zoo li no, thawj tsab xov xwm pom zoo kom tsis tu ncua ntawm cov qauv kuaj los ntawm cov khoom xa tuaj thiab kev sim ua kom pom tseeb ntawm qhov hu ua “cookies”, raws li tau hais tseg.
Raws li cov qauv uas tau hais hauv cov ntawv qub, kev ntsuas kev sib txuas yuav tsum tau ua ntawm qhov nruab nrab ntawm cov cement, dej thiab cua ntawm 18 mus rau 21 °C. Qhov xwm txheej no tseem ceeb rau kev soj ntsuam cov txiaj ntsig, vim tias thaum qhov kub thiab txias qis, lub sijhawm sib txuas ntxiv, thiab thaum kub nce, nws shortens. Nyob rau hauv cov xwm txheej tshwj xeeb, piv txwv li thaum lub sij hawm tsim kho ntawm cov pob zeb, kev sim ntxiv yog ua nyob rau lub caij ntuj sov ntawm qhov kub ntawm 30 mus rau 35 °C.
- Cov duab kos - kev teeb tsa thiab theem ntawm cov cement sib tov.*
Shrinkage thiab o ntawm cement
Cement slurry, tov nrog ntau cov dej uas yuav tsum tau rau cov pob zeb ntawm cov pob zeb ua vaj tse, dries thaum lub sij hawm teeb tsa yam tsis muaj kev tsim kom muaj zog hauv kev txhawb nqa nws lub hnab. Lub degree ntawm ziab yog nyob ntawm seb hom cement, qhov sib xyaw ntawm cov dej, qhov kub ntawm cov pob zeb thiab lwm yam kev mob.
Thaum siv cov cement tshiab rau ntau yam khoom siv, cov kab nrib pleb thiab tawg tau pom vim ziab hauv huab cua kub, qhuav thiab cua. Tom qab teeb tsa, cov cement shrinks yog tias nws qhuav tawm, thaum cov cement uas khaws cia kom ntub dej.
Ib qho duab - tawg ntawm cov cement nto.
Kev mob ntawm cov cement thaum lub sijhawm xa khoom thiab khaws cia
Sov cements
feem ntau nug seb cov cements sov li cas, piv txwv li kub ntawm 30 mus rau 80 °C, yog qhov phem dua li cov cement los ntawm qhov kub ntawm 10 mus rau 30 °C. Raws li cov ntawv qub, qhov kub ntawm cov cement nws tus kheej yog qhov tseem ceeb tsawg yog tias nws tau ua haujlwm zoo, piv txwv li yog cov pob zeb tshiab muaj qhov kub thiab txias ntawm 25 °C.
Nws yog ib qho tseem ceeb dua seb cov cement sov yog los ntawm cov clinkers tshiab uas tsis tau txias thiab tsis muaj hnub nyoog, los yog seb nws qhov kub thiab txias tau tsim thaum sib tsoo. Rau cov tsev tseem ceeb, nws raug nquahu kom siv cov cement uas muaj hnub nyoog tsawg kawg ib lub lim tiam.
Uniformity
Ib qho tseem ceeb ntawm cov cement zoo yog qhov sib xws ntawm cov khoom siv nyob rau lub sijhawm ntev, nrog kev txhim kho kom zoo thiab ua kom zoo dua qub.
Cia ruaj khov
Kev sim nrog Portland MAAs, ferruginous Portland MAAs, smelting thiab aluminate cement tau pom, thaum nws los txog rau niaj hnub cements, uas qhuav cia nyob rau hauv lub silo ntawm ib tug cement cog los yog nyob rau hauv lub hnab nyob rau hauv qhuav chav tsev, raws li zoo raws li ob peb lub hlis ntawm cia nyob rau hauv tshwj xeeb hnab thiab qhuav chav ua hauj lwm, tsis cuam tshuam lub zog ntawm cov cement.
Yog tias lub hnab ntim tau ntev ntev thiab cov cement tau clumped, nws yuav yog ib lub tswv yim zoo los sim cov cement tom qab. Thaum khaws cia hauv tsev, kev tiv thaiv los nag thiab cua yog tsim nyog. Yog tias qhov khaws cia no kav ntev li ob peb lub hlis, lub hnab yuav tsum tau tiv thaiv los ntawm txhua sab nrog cov ntawv vov tsev lossis cov khoom zoo sib xws. Cov hnab ntawv Bituminous lossis cov tso tsheb hlau luam tas mus li raug suav tias yog cov kev daws teeb meem zoo dua.
Illustration — cement cia silos.