1. Kub ntawm dej noo
Raws li qhov tso tawm ntawm qhov kub ntawm hydration dhau sijhawm, cov txheej txheem hydration ntawm cement feem ntau muab faib ua tsib theem, uas yog, lub sijhawm hydration pib (0 ~ 15 feeb), lub sijhawm induction (15 feeb ~ 4 teev), lub sijhawm acceleration thiab teeb tsa (4 teev ~ 8 teev), lub sijhawm deceleration thiab hardening (8 teev ~ 24 teev), thiab lub sijhawm kho (1d ~ 28d).
Cov txiaj ntsig ntawm kev sim qhia tau hais tias nyob rau theem thaum ntxov ntawm kev pib (piv txwv li, lub sijhawm pib hydration), thaum qhov ntau ntawm HEMC yog 0.1% piv nrog cov cement slurry dawb paug, lub ncov exothermic ntawm cov slurry tau nce qib thiab lub ncov tau nce ntxiv ntau. Thaum qhov ntau ntawmHEMCnce mus rau Thaum nws siab tshaj 0.3%, thawj qhov exothermic peak ntawm slurry raug ncua, thiab qhov siab tshaj plaws maj mam txo qis nrog qhov nce ntawm HEMC cov ntsiab lus; HEMC yuav pom tseeb ncua lub sijhawm induction thiab lub sijhawm nrawm ntawm cement slurry, thiab qhov ntau dua cov ntsiab lus, lub sijhawm induction ntev dua, qhov rov qab ntau dua lub sijhawm nrawm, thiab qhov me dua exothermic peak; qhov kev hloov pauv ntawm cellulose ether cov ntsiab lus tsis muaj qhov cuam tshuam rau qhov ntev ntawm lub sijhawm deceleration thiab lub sijhawm ruaj khov ntawm cement slurry, raws li pom hauv Daim Duab 3 (a) Nws tau qhia tias cellulose ether kuj tseem tuaj yeem txo qhov kub ntawm hydration ntawm cement paste hauv 72 teev, tab sis thaum qhov kub ntawm hydration ntev dua 36 teev, qhov kev hloov pauv ntawm cellulose ether cov ntsiab lus muaj qhov cuam tshuam me ntsis rau qhov kub ntawm hydration ntawm cement paste, xws li Daim Duab 3 (b).
Daim Duab 3 Qhov sib txawv ntawm qhov kub thiab txias ntawm cov cement paste nrog cov ntsiab lus sib txawv ntawm cellulose ether (HEMC)
2. Mcov khoom siv tshuab：
Los ntawm kev kawm ob hom cellulose ethers nrog viscosities ntawm 60000Pa · s thiab 100000Pa · s, nws tau pom tias lub zog compressive ntawm cov mortar hloov kho sib xyaw nrog methyl cellulose ether txo qis maj mam nrog kev nce ntawm nws cov ntsiab lus. Lub zog compressive ntawm cov mortar hloov kho sib xyaw nrog 100000Pa · s viscosity hydroxypropyl methyl cellulose ether nce ua ntej thiab tom qab ntawd txo qis nrog kev nce ntawm nws cov ntsiab lus (raws li pom hauv Daim Duab 4). Nws qhia tau hais tias kev koom ua ke ntawm methyl cellulose ether yuav txo qis lub zog compressive ntawm cement mortar. Qhov ntau ntxiv, lub zog me dua yuav yog; qhov me dua viscosity, qhov cuam tshuam loj dua rau kev poob ntawm mortar compressive zog; hydroxypropyl methyl cellulose ether Thaum cov koob tshuaj tsawg dua 0.1%, lub zog compressive ntawm mortar tuaj yeem nce ntxiv kom haum. Thaum cov koob tshuaj ntau dua 0.1%, lub zog compressive ntawm mortar yuav txo qis nrog kev nce ntawm cov koob tshuaj, yog li cov koob tshuaj yuav tsum tau tswj hwm ntawm 0.1%.
Daim Duab 4 3d, 7d thiab 28d lub zog compressive ntawm MC1, MC2 thiab MC3 modified cement mortar
(Methyl cellulose ether, viscosity 60000Pa·S, tom qab no hu ua MC1; methyl cellulose ether, viscosity 100000Pa·S, hu ua MC2; hydroxypropyl methylcellulose ether, viscosity 100000Pa·S, hu ua MC3).
3. Club sijhawm lottery：
Los ntawm kev ntsuas lub sijhawm teeb tsa ntawm hydroxypropyl methylcellulose ether nrog viscosity ntawm 100000Pa · s hauv cov koob tshuaj sib txawv ntawm cov cement paste, nws tau pom tias nrog kev nce ntawm HPMC koob tshuaj, lub sijhawm teeb tsa thawj zaug thiab lub sijhawm teeb tsa zaum kawg ntawm cov cement mortar tau ntev. Thaum qhov concentration yog 1%, lub sijhawm teeb tsa thawj zaug ncav cuag 510 feeb, thiab lub sijhawm teeb tsa zaum kawg ncav cuag 850 feeb. Piv nrog cov qauv dawb paug, lub sijhawm teeb tsa thawj zaug tau ntev los ntawm 210 feeb, thiab lub sijhawm teeb tsa zaum kawg tau ntev los ntawm 470 feeb (raws li pom hauv Daim Duab 5). Txawm hais tias nws yog HPMC nrog viscosity ntawm 50000Pa s, 100000Pa s lossis 200000Pa s, nws tuaj yeem ncua qhov teeb tsa ntawm cement, tab sis piv nrog peb cellulose ethers, lub sijhawm teeb tsa thawj zaug thiab lub sijhawm teeb tsa zaum kawg tau ntev nrog kev nce ntawm viscosity, raws li pom hauv Daim Duab 6. Qhov no yog vim tias cellulose ether raug nqus rau ntawm qhov chaw ntawm cov cement, uas tiv thaiv dej kom tsis txhob sib cuag nrog cov cement, yog li ncua qhov hydration ntawm cement. Qhov ntau dua viscosity ntawm cellulose ether, qhov tuab dua ntawm cov txheej adsorption ntawm qhov chaw ntawm cov cement, thiab qhov tseem ceeb dua qhov cuam tshuam retarding.
Daim Duab 5 Cov nyhuv ntawm cov cellulose ether cov ntsiab lus rau lub sijhawm teeb tsa ntawm cov mortar
Daim Duab 6 Cov nyhuv ntawm cov viscosities sib txawv ntawm HPMC rau lub sijhawm teeb tsa ntawm cov cement paste
(MC-5(50000Pa·s), MC-10(100000Pa·s) thiab MC-20(200000Pa·s))
Methyl cellulose ether thiab hydroxypropyl methyl cellulose ether yuav ua rau lub sijhawm teeb tsa ntawm cov cement slurry ntev dua, uas tuaj yeem ua kom ntseeg tau tias cov cement slurry muaj sijhawm txaus thiab dej rau kev ua kom dej noo, thiab daws qhov teeb meem ntawm lub zog qis thiab theem kawg ntawm cov cement slurry tom qab tawv. teeb meem tawg.
4. Kev khaws dej:
Kev kawm txog cov nyhuv ntawm cov cellulose ether rau kev khaws dej. Nws pom tau tias nrog rau kev nce ntxiv ntawm cov ntsiab lus ntawm cellulose ether, qhov ceev ntawm kev khaws dej ntawm cov mortar nce ntxiv, thiab thaum cov ntsiab lus ntawm cellulose ether ntau dua 0.6%, qhov ceev ntawm kev khaws dej feem ntau ruaj khov. Txawm li cas los xij, thaum piv peb hom cellulose ethers (HPMC nrog viscosity ntawm 50000Pa s (MC-5), 100000Pa s (MC-10) thiab 200000Pa s (MC-20)), qhov cuam tshuam ntawm viscosity rau kev khaws dej yog txawv. Kev sib raug zoo ntawm qhov ceev ntawm kev khaws dej yog: MC-5.
Lub sijhawm tshaj tawm: Plaub Hlis-28-2024