Lub admixture muaj cov txiaj ntsig zoo rau kev txhim kho kev ua haujlwm ntawm kev tsim kho kom qhuav-siv mortar, thiab cov hmoov roj hmab rov qab yog ua los ntawm cov khoom tshwj xeeb polymer emulsion tom qab cov tshuaj tsuag kom qhuav. Cov hmoov roj hmab qhuav yog qee qhov sib txawv ntawm 80 ~ 100mm sib sau ua ke. Cov khoom no yog soluble nyob rau hauv dej thiab tsim ib tug ruaj khov dispersion me ntsis loj dua cov thawj emulsion hais, uas tsim ib zaj duab xis tom qab lub cev qhuav dej thiab qhuav.
Kev hloov pauv sib txawv ua rau cov hmoov av rov ua dua tshiab muaj cov khoom sib txawv xws li dej tsis kam, alkali tsis kam, huab cua tsis kam thiab yoog raws. Roj hmab hmoov siv hauv mortar tuaj yeem txhim kho qhov cuam tshuam tsis zoo, ua haujlwm ntev, hnav tsis kam, yooj yim ntawm kev tsim kho, kev sib txuas lub zog thiab kev sib koom ua ke, huab cua tsis kam, khov-thaw tsis kam, dej tiv thaiv, khoov lub zog thiab flexural zog ntawm mortar. Tsuav yog cov khoom siv cement-based nrog cov hmoov latex nyob rau hauv kev sib cuag nrog dej, cov tshuaj tiv thaiv hydration yuav pib, thiab cov tshuaj calcium hydroxide yuav sai sai saturated thiab crystals yuav precipitated. Nyob rau tib lub sijhawm, ettringite crystals thiab calcium silicate hydrate gels yuav raug tsim. Cov khoom siv tau muab tso rau ntawm cov gel thiab cov cement uas tsis muaj dej. Raws li cov tshuaj tiv thaiv hydration zuj zus, cov khoom hydration nce, thiab cov khoom siv polymer maj mam sib sau ua ke nyob rau hauv lub capillary pores, tsim ib txheej densely packed nyob rau saum npoo ntawm gel thiab nyob rau hauv unhydrated cement hais. Lub aggregated polymer hais maj mam sau lub pores.
Redispersible latex hmoov tuaj yeem txhim kho lub zog dabtsi yog khoov thiab adhesion lub zog ntawm mortar vim nws tuaj yeem tsim ib zaj duab xis polymer rau saum npoo ntawm cov khoom khib nyiab. Muaj cov pores nyob rau saum npoo ntawm zaj duab xis, thiab qhov chaw ntawm lub qhov hws yog ntim nrog mortar, uas txo cov kev ntxhov siab concentration. Thiab nyob rau hauv qhov kev txiav txim ntawm sab nraud quab yuam, nws yuav tsim kev so tsis muaj kev tawg. Tsis tas li ntawd, cov mortar tsim ib lub cev pob txha nruj tom qab cov cement yog hydrated, thiab cov polymer nyob rau hauv lub pob txha pob txha muaj kev ua haujlwm ntawm lub cev txav tau, uas zoo ib yam li cov ntaub so ntswg ntawm tib neeg lub cev. Lub membrane tsim los ntawm cov polymer tuaj yeem muab piv rau cov pob qij txha thiab ligaments, thiaj li ua kom lub elasticity thiab yooj ntawm cov pob txha pob txha. tawv.
Nyob rau hauv lub polymer-hloov cement mortar system, qhov nruam thiab ua tiav polymer zaj duab xis yog interwoven nrog cement paste thiab xuab zeb hais, ua rau tag nrho cov mortar finer thiab denser, thiab nyob rau tib lub sij hawm ua rau tag nrho cov elastic network los ntawm txhaws capillaries thiab kab noj hniav. Yog li ntawd, cov yeeb yaj kiab polymer tuaj yeem xa cov siab thiab elastic nro. Cov yeeb yaj kiab polymer tuaj yeem txuas cov kab nrib pleb ntawm qhov sib txuas ntawm polymer-mortar, kho cov kab nrib pleb, thiab txhim kho lub sealing thiab cohesive zog ntawm mortar. Lub xub ntiag ntawm cov hloov pauv tau yooj yim thiab muaj zog heev ntawm cov khoom siv polymer txhim kho qhov hloov tau yooj yim thiab elasticity ntawm cov mortar, muab kev sib koom ua ke thiab kev coj cwj pwm zoo rau lub cev pob txha. Thaum siv cov quab yuam sab nraud, cov txheej txheem microcrack propagation yog ncua vim kev txhim kho yooj thiab elasticity kom txog thaum muaj kev ntxhov siab ntau dua. Lub interwoven polymer domains kuj ua raws li ib tug barrier rau lub coalescence ntawm microcracks rau nkag mus rau hauv cov kab nrib pleb. Yog li ntawd, cov respersible polymer hmoov txhim kho qhov tsis ua hauj lwm kev nyuaj siab thiab tsis ua hauj lwm strain ntawm cov khoom.
Post lub sij hawm: Feb-20-2023