Thaum cov polycarboxylic acid-raws li high-efficiency superplasticizer (dej txo tus neeg sawv cev) yog ntxiv rau hauv ib qho nyiaj ntawm 0.2% mus rau 0.3% ntawm qhov loj ntawm cov khoom cementitious, cov dej-txo tus nqi yuav siab li 25% mus rau 45%. Nws yog feem ntau ntseeg tias polycarboxylic acid-based high-efficiency dej-txo tus neeg sawv cev muaj cov qauv zoo li lub zuag, uas ua rau muaj kev cuam tshuam tsis zoo los ntawm adsorbing ntawm cov cement hais los yog cov khoom cement hydration, thiab plays lub luag hauj lwm hauv dispersing thiab tswj cov dispersion ntawm cov cement. Txoj kev tshawb no ntawm cov yam ntxwv adsorption ntawm cov dej-txo cov neeg ua hauj nyob rau saum npoo ntawm gypsum hais thiab lawv cov adsorption-dispersion mechanism tau qhia tias polycarboxylic acid-raws li high-efficiency dej-txo tus neeg saib xyuas yog ib tug zuag-puab adsorption, nrog ib tug me me ntawm adsorption ntawm gypsum nto thiab ib tug tsis muaj zog electrostatic repulsion. Nws cov nyhuv dispersing feem ntau yog los ntawm steric hindrance nyhuv ntawm txheej adsorption. Lub dispersibility tsim los ntawm steric hindrance nyhuv yog tsawg cuam tshuam los ntawm hydration ntawm gypsum, thiab yog li muaj zoo dispersion stability.
Cement muaj qhov teeb tsa-txhim kho cov nyhuv hauv gypsum, uas yuav ua kom lub sijhawm teem sijhawm ntawm gypsum. Thaum cov koob tshuaj ntau tshaj 2%, nws yuav muaj kev cuam tshuam loj heev rau cov kua dej thaum ntxov, thiab cov fluidity yuav deteriorate nrog nce ntawm cov cement ntau npaum. Txij li cov cement muaj qhov teeb tsa-txhim kho cov nyhuv ntawm gypsum, txhawm rau txo qhov cuam tshuam ntawm gypsum teeb lub sij hawm ntawm gypsum fluidity, qhov tsim nyog ntawm gypsum retarder yog ntxiv rau gypsum. Lub fluidity ntawm gypsum nce nrog kev nce ntawm cov cement ntau npaum; Qhov sib ntxiv ntawm cov cement tsub kom cov alkalinity ntawm lub system, ua rau cov dej reducer dissociate sai thiab ntau dua nyob rau hauv lub system, thiab cov dej-txo cov nyhuv yog ho txhim khu kev qha; Nyob rau tib lub sijhawm, txij li cov dej xav tau ntawm cov cement nws tus kheej yog qhov tsawg, nws yog qhov sib npaug ntawm qhov sib npaug ntawm cov dej-cement piv nyob rau hauv tib tus nqi ntawm cov dej ntxiv, uas yuav ua rau kom cov fluidity me ntsis.
Polycarboxylate dej reducer muaj kev cuam tshuam zoo heev thiab tuaj yeem txhim kho cov dej ntws ntawm gypsum ntawm qhov ntau npaum li cas. Nrog rau qhov nce ntawm ntau npaum, qhov fluidity ntawm gypsum nce ntau. Polycarboxylate dej reducer muaj qhov muaj zog retarding nyhuv. Nrog rau qhov nce ntau npaum li cas, lub sijhawm teem sijhawm nce ntxiv. Nrog rau qhov muaj zog retarding nyhuv ntawm polycarboxylate dej reducer, nyob rau hauv tib qhov dej-rau-cement piv, qhov ntau npaum li cas yuav ua rau deformation ntawm gypsum crystals thiab loosening ntawm gypsum. Lub flexural thiab compressive zog ntawm gypsum txo nrog qhov nce ntawm ntau npaum.
Polycarboxylate ether dej-txo cov neeg ua haujlwm qeeb qhov chaw ntawm gypsum thiab txo nws lub zog. Nyob rau tib qhov ntau npaum, ntxiv cov cement lossis calcium oxide rau gypsum txhim kho nws cov fluidity. Qhov no txo qis cov dej-rau-cement piv, nce qhov ceev ntawm gypsum, thiab yog li nws lub zog. Tsis tas li ntawd, qhov kev txhawb zog ntawm cov khoom siv cement hydration ntawm gypsum nce nws cov flexural thiab compressive zog. Ua kom cov cement thiab calcium oxide ua kom cov dej ntws ntawm cov gypsum, thiab cov cement tsim nyog tuaj yeem txhim kho nws lub zog.
Thaum siv polycarboxylate ether dej-txo cov neeg ua haujlwm hauv gypsum, ntxiv cov cement tsim nyog tsis yog tsuas yog ua kom nws lub zog tab sis kuj muab ntau dua fluidity nrog tsawg heev ntawm nws lub sijhawm teem.
Post lub sij hawm: Aug-06-2025