EPS particle rwb thaiv tsev mortar yog cov khoom siv hluav taws xob sib sib zog ua los ntawm kev sib xyaw inorganic binders, organic binders, admixtures, additives thiab lub teeb aggregates nyob rau hauv ib qho kev faib ua feem. Ntawm EPS particle rwb thaiv tsev mortars tam sim no kawm thiab siv, redispersible latex hmoov muaj kev cuam tshuam ntau dua rau kev ua haujlwm ntawm cov tshuaj khib nyiab, suav nrog ntau tus nqi, thiab ib txwm ua kom pom tseeb. Kev sib koom ua ke ntawm EPS particle rwb thaiv tsev mortar sab nrauv phab ntsa rwb thaiv tsev feem ntau yog los ntawm cov ntaub ntawv polymer, uas feem ntau yog tsim los ntawm vinyl acetate / ethylene copolymer. Txau kom qhuav ntawm hom polymer emulsion no tuaj yeem tsim cov hmoov latex redispersible. Redispersible latex hmoov tau dhau los ua kev txhim kho hauv kev tsim kho vim nws qhov kev npaj meej, kev thauj mus los yooj yim thiab khaws cia yooj yim. Qhov kev ua tau zoo ntawm EPS particle rwb thaiv tsev mortar yog nyob ntawm ntau yam ntawm cov khoom siv thiab cov khoom siv polymer. Ethylene-vinyl acetate hmoov (EVA) nrog cov ntsiab lus ethylene siab thiab qis Tg (iav hloov kub) tus nqi muaj kev ua tau zoo heev hauv kev cuam tshuam lub zog, kev sib txuas lub zog thiab dej tsis kam.
Redispersible polymer hmoov yog dawb, muaj fluidity zoo, muaj cov khoom me me tom qab redispersion, thiab muaj qhov zoo dispersibility. Tom qab sib tov nrog dej, cov hmoov latex tuaj yeem rov qab mus rau lawv cov qub emulsion lub xeev thiab tswj cov yam ntxwv thiab kev ua haujlwm raws li cov organic binder. Lub luag hauj lwm ntawm redispersible polymer hmoov nyob rau hauv thermal rwb thaiv tsev mortar yog tswj los ntawm ob txheej txheem: cement hydration thiab polymer hmoov zaj duab xis tsim. Cov txheej txheem tsim cov txheej txheem ntawm cement hydration thiab polymer hmoov zaj duab xis tsim yog ua tiav los ntawm plaub kauj ruam hauv qab no:
(1) Thaum cov hmoov latex sib xyaw nrog cov cement mortar, cov khoom tawg yooj yim zoo polymer yog sib npaug hauv cov slurry.
(2) Cement gel yog maj mam tsim nyob rau hauv cov polymer / cement paste los ntawm hydration ntawm cov cement, cov theem ua kua yog saturated nrog calcium hydroxide tsim thaum lub sij hawm hydration txheej txheem, thiab cov khoom polymer yog tso rau ntawm ib feem ntawm cov cement gel / unhydrated. cement particle sib tov.
(3) Raws li cov qauv cement gel tsim, dej tau siv thiab cov khoom siv polymer yog maj mam kaw hauv cov hlab ntsha. Raws li cov cement ntxiv hydrates, cov dej hauv capillaries txo qis thiab cov khoom siv polymer sib sau ua ke ntawm cov cement gel / unhydrated cement particle sib tov thiab lub teeb aggregates, tsim ib txheej nruam thiab nruj. Nyob rau lub sijhawm no, lub qhov hws loj yog ntim nrog cov nplaum los yog nws tus kheej-adhesive polymer hais.
(4) Nyob rau hauv qhov kev txiav txim ntawm cement hydration, lub hauv paus nqus thiab evaporation ntawm qhov chaw, cov dej noo ntxiv yog txo, thiab cov khoom siv polymer nruj nruj ntawm cov cement hydrate aggregate rau hauv cov yeeb yaj kiab tas mus li, sib txuas cov khoom hydration ua ke los tsim ib qho kev ua tiav network. , thiab cov theem polymer yog interspersed thoob plaws hauv cov cement hydration slurry.
Cement hydration thiab latex hmoov zaj duab xis-tsim muaj pes tsawg leeg tsim ib qho kev sib xyaw tshiab, thiab lawv cov txiaj ntsig ua ke txhim kho thiab txhim kho kev ua haujlwm ntawm thermal rwb thaiv tsev mortar.
Cov nyhuv ntawm polymer hmoov ntxiv rau thermal rwb thaiv tsev mortar zog
Qhov hloov pauv tau yooj yim thiab elastic heev polymer mesh membrane tsim los ntawm latex hmoov ho txhim kho cov kev ua tau zoo ntawm thermal rwb thaiv tsev mortar, tshwj xeeb tshaj yog lub zog tensile zoo heev. Thaum siv cov quab yuam sab nraud, qhov tshwm sim ntawm micro-cracks yuav raug offset los yog qeeb vim kev txhim kho ntawm tag nrho cov cohesion ntawm mortar thiab elasticity ntawm cov polymer.
Lub zog tensile ntawm thermal rwb thaiv tsev mortar nce nrog kev nce ntawm polymer hmoov cov ntsiab lus; lub zog flexural thiab compressive zog txo mus rau ib qho twg nrog qhov nce ntawm latex hmoov cov ntsiab lus, tab sis tseem tuaj yeem ua tau raws li qhov yuav tsum tau ua ntawm phab ntsa sab nrauv kho kom zoo nkauj. Lub compression flexure yog me me, uas qhia tau hais tias lub thermal rwb thaiv tsev mortar muaj qhov yooj yooj yim thiab deformation kev ua tau zoo.
Cov laj thawj tseem ceeb vim li cas cov hmoov polymer txhim kho lub zog tensile yog: thaum lub sij hawm coagulation thiab hardening txheej txheem ntawm mortar, lub polymer yuav gel thiab tsim ib zaj duab xis nyob rau hauv lub hloov chaw ntawm EPS hais thiab cement paste, ua rau lub interface ntawm ob denser thiab muaj zog; ib feem ntawm cov polymer yog dispersed rau hauv cov cement paste thiab condensed rau hauv ib zaj duab xis ntawm cov cement hydrate gel los tsim ib lub network polymer. Qhov no tsis tshua muaj elastic modulus polymer network txhim kho lub toughness ntawm hardened cement; tej pawg polar nyob rau hauv cov polymer molecules kuj yuav hnov mob nrog cov khoom siv cement hydration los tsim cov teebmeem tshwj xeeb, yog li kev txhim kho lub cev ntawm cov khoom cement hydration thiab alleviating internal stress, yog li txo cov tiam ntawm microcracks hauv cov cement paste.
Cov nyhuv ntawm redispersible polymer hmoov ntau npaum li cas ntawm kev ua haujlwm ntawm EPS thermal rwb thaiv tsev mortar
Nrog rau qhov nce ntawm cov hmoov latex ntau npaum li cas, kev sib koom ua ke thiab kev tuav dej tau zoo dua qub, thiab kev ua haujlwm tau zoo. Thaum cov koob tshuaj nce mus txog 2.5%, nws tuaj yeem ua tau raws li kev tsim kho. Yog tias qhov ntau npaum li cas, qhov viscosity ntawm EPS thermal rwb thaiv tsev mortar yog siab dhau thiab fluidity tsawg, uas tsis tsim nyog rau kev tsim kho, thiab tus nqi mortar nce.
Yog vim li cas yog vim li cas polymer hmoov optimizes kev ua hauj lwm ntawm mortar yog tias cov hmoov polymer yog ib tug siab molecular polymer nrog polar pawg. Thaum cov hmoov polymer sib xyaw nrog EPS cov khoom, cov ntu uas tsis yog-polar nyob rau hauv cov saw tseem ceeb ntawm cov hmoov polymer yuav cuam tshuam nrog EPS hais. Lub cev adsorption tshwm sim ntawm qhov tsis-polar nto ntawm EPS. Cov pawg polar hauv cov polymer yog taw qhia sab nraud ntawm EPS cov khoom, ua rau EPS cov khoom hloov ntawm hydrophobic mus rau hydrophilic. Vim qhov kev hloov pauv ntawm cov hmoov latex rau saum npoo ntawm EPS cov khoom, qhov teeb meem uas EPS cov khoom tau yooj yim raug rau dej yog daws tau. Qhov teeb meem ntawm floating thiab loj mortar txheej. Thaum cov cement ntxiv thiab sib xyaw rau lub sijhawm no, pawg polar adsorbed rau ntawm qhov chaw ntawm EPS cov khoom sib cuam tshuam nrog cov cement thiab sib xyaw ua ke, yog li txhim kho kev ua haujlwm ntawm EPS rwb thaiv tsev mortar. Qhov no tau tshwm sim nyob rau hauv qhov tseeb hais tias EPS hais tau yooj yim wetted los ntawm cov cement slurry, thiab lub zog sib txuas ntawm ob qho kev txhim kho zoo heev.
Redispersible polymer hmoov yog ib qho tseem ceeb ntawm kev ua haujlwm siab EPS particle rwb thaiv tsev slurry. Nws cov txheej txheem ntawm kev ua haujlwm feem ntau yog cov khoom siv polymer hauv cov txheej txheem sib sau ua ke rau hauv cov yeeb yaj kiab tas mus li, sib txuas cov cement hydration khoom ua ke los tsim ib qho kev sib txuas ua tiav thiab ruaj khov ua ke nrog EPS hais. Cov txheej txheem sib xyaw ua ke ntawm cov khoom siv rov ua dua tshiab polymer hmoov thiab lwm cov binders muaj cov nyhuv elastic zoo, uas zoo heev txhim kho lub zog tensile thiab kev tsim kho ntawm EPS particle rwb thaiv tsev mortar.
Post lub sij hawm: Dec-30-2024