Cov tshuaj admixture muaj cov txiaj ntsig zoo rau kev txhim kho kev ua haujlwm ntawm cov mortar qhuav sib xyaw ua ke. Cov hmoov latex uas rov ua dua tshiab yog ua los ntawm cov polymer emulsion tshwj xeeb tom qab txau kom qhuav. Cov hmoov latex qhuav yog qee cov khoom me me ntawm 80 ~ 100 hli sib sau ua ke. Cov khoom me me no yaj hauv dej thiab tsim cov khoom sib xyaw ruaj khov me ntsis loj dua li cov khoom emulsion qub, uas tsim cov zaj duab xis tom qab ziab thiab ziab.
Cov kev hloov kho sib txawv ua rau cov hmoov latex uas tawg tau dua tshiab muaj cov yam ntxwv sib txawv xws li kev tiv taus dej, kev tiv taus alkali, kev tiv taus huab cua thiab kev ywj pheej. Cov hmoov latex siv rau hauv cov mortar tuaj yeem txhim kho kev tiv taus kev cuam tshuam, kev ruaj khov, kev tiv taus hnav, yooj yim ntawm kev tsim kho, lub zog sib txuas thiab kev sib koom ua ke, kev tiv taus huab cua, kev tiv taus khov-thaw, kev tiv taus dej, lub zog khoov thiab lub zog khoov ntawm cov mortar. Thaum cov khoom siv cement-based ntxiv nrog cov hmoov latex kov dej, qhov kev ua kom dej pib, thiab cov tshuaj calcium hydroxide sai sai mus txog qhov saturation thiab cov siv lead ua tau precipitated, thiab tib lub sijhawm, ettringite siv lead ua thiab calcium silicate hydrate gels tau tsim. Cov khoom khov tau tso rau ntawm cov gel thiab cov khoom cement tsis muaj dej. Thaum cov tshuaj tiv thaiv hydration txuas ntxiv mus, cov khoom hydration nce ntxiv, thiab cov khoom polymer maj mam sib sau ua ke hauv cov qhov hws capillary, tsim cov txheej txheem ntim khoom ntawm qhov chaw ntawm cov gel thiab ntawm cov khoom cement tsis muaj dej. Cov khoom polymer sib sau ua ke maj mam sau cov qhov hws.
Cov hmoov latex uas tawg tau dua tuaj yeem txhim kho cov yam ntxwv ntawm cov mortar xws li lub zog flexural thiab lub zog adhesion, vim nws tuaj yeem tsim cov zaj duab xis polymer ntawm qhov chaw ntawm cov khoom mortar. Muaj cov qhov hws ntawm qhov chaw ntawm zaj duab xis, thiab qhov chaw ntawm cov qhov hws puv nrog mortar, uas txo qhov kev ntxhov siab. Thiab nyob rau hauv qhov kev ua ntawm lub zog sab nraud, nws yuav tsim kev so tsis tawg. Tsis tas li ntawd, cov mortar tsim cov pob txha khov kho tom qab cov cement tau hydrated, thiab cov polymer hauv cov pob txha muaj lub luag haujlwm ntawm cov pob qij txha 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 piv rau cov pob qij txha thiab ligaments, yog li kom ntseeg tau tias qhov elasticity thiab kev ywj pheej ntawm cov pob txha khov kho. toughness.
Hauv lub tshuab cement mortar uas hloov kho los ntawm polymer, cov zaj duab xis polymer uas txuas ntxiv thiab tiav lawm yog sib xyaw nrog cov cement paste thiab cov xuab zeb me me, ua rau tag nrho cov mortar zoo dua thiab ntom dua, thiab tib lub sijhawm ua rau tag nrho cov network elastic los ntawm kev sau cov hlab ntsha thiab cov qhov. Yog li ntawd, cov zaj duab xis polymer tuaj yeem xa cov siab thiab elastic tension tau zoo. Cov zaj duab xis polymer tuaj yeem txuas cov kab nrib pleb ntawm qhov sib txuas polymer-mortar, kho cov kab nrib pleb, thiab txhim kho lub zog sealing thiab cohesive ntawm cov mortar. Qhov muaj cov polymer domains uas yooj ywm thiab elastic heev txhim kho qhov yooj ywm thiab elasticity ntawm cov mortar, muab kev sib koom ua ke thiab kev coj cwj pwm dynamic rau cov pob txha rigid. Thaum siv lub zog sab nraud, cov txheej txheem microcrack propagation raug ncua vim yog qhov yooj ywm thiab elasticity zoo dua kom txog thaum muaj kev ntxhov siab ntau dua. Cov polymer domains uas sib xyaw ua ke kuj ua lub luag haujlwm tiv thaiv kev sib koom ua ke ntawm cov microcracks rau hauv cov kab nrib pleb. Yog li ntawd, cov hmoov polymer redispersible txhim kho qhov kev ntxhov siab tsis ua haujlwm thiab kev ntxhov siab tsis ua haujlwm ntawm cov khoom.
Lub sijhawm tshaj tawm: Lub Peb Hlis-10-2023