Cellulose ether siv rau dab tsi?

Cellulose etheryuav ua rau lub sijhawm teeb tsa ntawm cov cement paste lossis mortar net ntev dua, ncua qhov cement hydration kinetics, uas yog qhov zoo rau kev txhim kho lub sijhawm ua haujlwm ntawm cov khoom siv cement, txhim kho qhov sib xws thiab cov pob zeb poob tom qab poob, tab sis kuj tseem yuav ncua kev nce qib ntawm kev tsim kho, tshwj xeeb tshaj yog nyob rau hauv qhov kub qis rau kev siv mortar thiab pob zeb.

Feem ntau, cov ntsiab lus ntawm cellulose ether siab dua, lub sijhawm teeb tsa ntawm cov cement slurry thiab mortar ntev dua, thiab qhov pom tseeb dua qhov qeeb ntawm cov dej noo. Cellulose ether tuaj yeem ncua qhov dej noo ntawm cov khoom siv clinker tseem ceeb tshaj plaws tricalcium aluminate (C3A) thiab tricalcium silicate (C3S) hauv cement, tab sis qhov cuam tshuam rau lawv cov hydration kinetics tsis zoo ib yam. Cellulose ether feem ntau txo qhov nrawm ntawm C3S hauv theem kev nrawm, thaum rau C3A-Caso4 system, nws feem ntau ncua lub sijhawm induction.

Cov kev sim ntxiv qhia tau tias cellulose ether tuaj yeem tiv thaiv kev yaj ntawm C3A thiab C3S, ncua qhov crystallization ntawm hydrated calcium aluminate thiab calcium hydroxide, thiab txo qhov nucleation thiab kev loj hlob ntawm CSH ntawm qhov chaw ntawm C3S cov khoom me me, tab sis tsis muaj feem cuam tshuam rau ettringite siv lead ua. Weyer et al. pom tias qib ntawm kev hloov pauv DS yog qhov tseem ceeb tshaj plaws uas cuam tshuam rau cement hydration, thiab DS me dua, qhov pom tseeb dua qhov qeeb cement hydration yog. Ntawm lub tshuab ntawm cellulose ether ncua cement hydration.

Sliva et al. ntseeg tias cellulose ether ua rau cov kua dej pore viscosity ntau ntxiv thiab cuam tshuam qhov nrawm ntawm kev txav mus los ntawm ion, yog li ntawd qeeb qeeb rau kev ua kom cov cement hydration. Txawm li cas los xij, Pourchez et al. pom tias kev sib raug zoo ntawm cellulose ether qeeb qeeb rau kev ua kom cov cement hydration thiab cov cement slurry viscosity tsis pom tseeb. Schmitz et al. pom tias qhov viscosity ntawm cellulose ether yuav luag tsis muaj kev cuam tshuam rau qhov hydration kinetics ntawm cement.

Pourchez kuj pom tias cellulose ether ruaj khov heev nyob rau hauv alkaline mob thiab nws cov cement hydration qeeb tsis tuaj yeem raug suav hais tias yog qhov ua rau lwj ntawmcellulose etherTej zaum qhov ua rau cellulose ether qeeb cov cement hydration, ntau cov organic additives yuav raug adsorbed rau cov cement me me thiab cov khoom hydration, tiv thaiv kev yaj ntawm cov cement me me thiab cov crystallization ntawm cov khoom hydration, yog li ncua qhov hydration thiab condensation ntawm cement. Pourchcz et al. pom tias qhov muaj zog ntawm lub peev xwm adsorption ntawm cov khoom hydration thiab cellulose ether, qhov ntau pom tseeb qhov qeeb.

Feem ntau ntseeg tias cov cellulose ether molecules feem ntau yog adsorbed rau ntawm cov khoom hydration thiab tsis tshua muaj adsorbed rau ntawm cov khoom qub ntawm clinker.