Cellulose ether siv rau dab tsi?

Cellulose etheryuav ncua sij hawm teem caij ntawm cov cement paste lossis mortar net, ncua lub cement hydration kinetics, uas yog qhov zoo los txhim kho lub sijhawm ua haujlwm ntawm cov khoom siv cement, txhim kho qhov sib xws thiab cov pob zeb tawg tom qab poob, tab sis kuj tseem tuaj yeem ncua kev tsim kho, tshwj xeeb tshaj yog nyob rau hauv qhov kub thiab txias ib puag ncig rau kev siv mortar thiab pob zeb.

Feem ntau, qhov siab dua cov ntsiab lus ntawm cellulose ether, lub sij hawm ntev ntawm cov cement slurry thiab mortar, thiab qhov pom tseeb dua qhov qeeb hydration dynamics. Cellulose ether tuaj yeem ncua qhov dej ntawm qhov tseem ceeb tshaj plaws clinker ntxhia theem tricalcium aluminate (C3A) thiab tricalcium silicate (C3S) hauv cov cement, tab sis cov nyhuv ntawm lawv cov dej kinetics tsis zoo ib yam. Cellulose ether tsuas yog txo cov tshuaj tiv thaiv ntawm C3S nyob rau hauv lub acceleration theem, thaum rau C3A-Caso4 system, nws tsuas yog ncua lub sij hawm induction.

Cov kev sim ntxiv tau pom tias cellulose ether tuaj yeem cuam tshuam qhov kev sib cais ntawm C3A thiab C3S, ncua lub crystallization ntawm hydrated calcium aluminate thiab calcium hydroxide, thiab txo cov nucleation thiab loj hlob tus nqi ntawm CSH rau ntawm qhov chaw ntawm C3S hais, tab sis muaj me ntsis cuam tshuam rau ettringite crystals. Weyer et al. pom tias qhov kev hloov pauv DS yog qhov tseem ceeb cuam tshuam rau cov cement hydration, thiab DS me dua, qhov pom tseeb dua qhov kev ncua ntawm cement hydration yog. Ntawm cov txheej txheem ntawm cellulose ether ncua cement hydration.

Sliva et al. ntseeg hais tias cellulose ether nce viscosity ntawm pore tov thiab hindered tus nqi ntawm ion zog, yog li ncua cov cement hydration. Txawm li cas los xij, Pourchez et al. pom tias kev sib raug zoo ntawm cellulose ether ncua cov cement hydration thiab cement slurry viscosity tsis pom tseeb. Schmitz et al. pom tias viscosity ntawm cellulose ether yuav luag tsis cuam tshuam rau hydration kinetics ntawm cement.

Pourchez kuj pom tias cellulose ether ruaj khov heev nyob rau hauv alkaline tej yam kev mob thiab nws ncua sij hawm cement hydration tsis tuaj yeem raug ntaus nqi rau qhov decomposition ntawmcellulose ether. Adsorption tej zaum yuav yog vim li cas tiag tiag cellulose ether ncua cement hydration, ntau cov organic additives yuav adsorbed rau cov cement hais thiab hydration cov khoom, tiv thaiv lub dissolution ntawm cement hais thiab crystallization ntawm hydration khoom, yog li ncua lub hydration thiab condensation ntawm cement. Pourchcz et al. pom tias lub zog adsorption muaj peev xwm ntawm cov khoom hydration thiab cellulose ether, qhov pom tseeb dua qhov qeeb.

Nws feem ntau ntseeg tias cellulose ether molecules feem ntau yog adsorbed ntawm cov khoom hydration thiab tsis tshua muaj adsorbed ntawm thawj theem ntxhia ntawm clinker.