Dab tsi ntxiv rau pob zeb kom qeeb qeeb sij hawm?

Pob zeb tshuav nws cov txiaj ntsig zoo li cov khoom siv hauv tsev rau cov txheej txheem cement hydration, cov txheej txheem nyuaj ntawm cov tshuaj tiv thaiv ntawm cov cement thiab dej. Cov txheej txheem no hloov cov pob zeb los ntawm qhov pib yas thiab yooj yim moldable loj rau hauv cov khoom tsis zoo thiab cov khoom siv tiv thaiv zoo ib yam li pob zeb. Raws li cov tshuaj tiv thaiv ntawm cov dej thiab cov cement nce mus, ob lub cev-mechanical variations tshwm sim:

1. Kev teeb tsa: Qhov no yog qhov kev poob qis ntawm qhov pib ua haujlwm ntawm cov pob zeb tshiab kom txog rau thaum cov khoom sib tov tsis tuaj yeem moldable.

2. Hardening: Qhov no yog qhov tom ntej thiab nce zuj zus ntawm cov neeg kho tshuab tsis kam.

Qhov teeb tsa tus nqi yog cuam tshuam los ntawm ntau yam, suav nrog qhov kub thiab txias, av noo, tus nqi ntawm cov dej siv, thiab muaj qee qhov sib xyaw xws li cov accelerators lossis retarders.

Kub thiab Teem Sijhawm

Kubyog ib qho tseem ceeb tshaj plaws uas cuam tshuam rau kev teeb tsa lub sijhawm. Feem ntau, qhov kub thiab txias ua rau qhov kev teeb tsa tus nqi qis, thaum qhov kub qis qis nws qeeb. Qhov no yog vim muaj tshuaj lom neeg cov tshuaj tiv thaiv ntawm cov dej thiab cov cement, hu ua hydration, tshwm sim thaum lub sijhawm teeb tsa.

Nyob rau hauv cov huab cua kub, lub kinetics ntawm cov tshuaj tiv thaiv hydration nce, ua rau lub sij hawm luv luv. Qhov no tuaj yeem ua rau tawg ntawm cov pob zeb ua ke nrog rau lub zog txo lub sijhawm. Qhov no yog qhov twgretarding admixturestsim los ntawm cov tuam ntxhab zoo li Borida hauv Suav teb ua qhov tseem ceeb.

Dab tsi yog Retarding Admixtures?

Retarding admixtureskev ua haujlwm kom txo qis cov dej ntawm cov cement hauv thawj cov xuab moos, tshwj xeeb tshaj yog nyob rau hauv cov huab cua kub qhov chaw kub ceev ceev cov txheej txheem hydration, cuam tshuam kev thauj cov pob zeb (tsis ua haujlwm). Cov admixtures no tau ntxiv rau qhov sib xyaw ua ke kom qeeb lub sijhawm teeb tsa, tso cai rau kev ua haujlwm ntxiv rau lub sijhawm ntev ua ntej hardening. Qhov no yog qhov tshwj xeeb tshaj yog nyob rau hauv huab cua kub, qhov chaw ua vaj tse complex, tshwj xeeb nto tiav, tiv thaiv kev sib koom ua ke txias, thiab lwm yam.

Cov txiaj ntsig ntawm Retarding Admixtures:

• Ua haujlwm tau zoo
• Txhim kho pumpability ntawm pob zeb
• Txo poob poob
• Kev tiv thaiv ntawm pob zeb los ntshav
• Txo qhov tsis xws luag xws li tawg thiab shrinkage
• Tsawg pov tseg

Yuav Ua Li Cas Retarding Admixtures Counter Teem Sijhawm Acceleration

Nyob rau hauv huab cua kub, lub sij hawm teem ntawm cov pob zeb sib tov zoo li nrawm. Txhawm rau tiv thaiv qhov teeb meem no, cov khoom siv tshuaj sib xyaw zoo li Borida pom zoo kom siv cov tshuaj tiv thaiv retarding. Cov admixtures no ua haujlwm los ntawm kev ncua lossis cuam tshuam nrog cov txheej txheem hydration, uas ua rau lub zog ntawm cov pob zeb.

Mechanism:

• Retarding admixtures ncua lub hydration txheej txheem los ntawm txheej cov cement hais nrog ib tug nyias zaj duab xis, tiv thaiv lawv los ntawm reacting nrog dej.
• Qhov no yog ua tiav los ntawm lub cev los yog tshuaj thaiv qhov chaw uas cov dej molecules feem ntau yuav txuas lawv tus kheej mus rau cov cement hais.

Cov ntsiab lus tseem ceeb:

• Tus nqi ntawm retarding admixture siv yuav tsum tau ua tib zoo tswj. Ntau dhau retarder tuaj yeem ua rau cov pob zeb ua kom mos thiab tsis muaj zog, thaum me me yuav tsis txaus rau lub sijhawm teem sijhawm.

Xaus

Retarding admixturesyog qhov tseem ceeb rau kev tsim kho, tshwj xeeb tshaj yog nyob rau hauv huab cua kub. Lawv ua rau lub sijhawm teem sijhawm ntawm cov pob zeb ua haujlwm qeeb, muab sijhawm rau cov neeg ua haujlwm ntxiv sijhawm rau qhov chaw thiab ua tiav cov khoom, uas ua kom cov pob zeb zoo tag nrho thiab txo qhov kev pheej hmoo ntawm kev tawg thiab shrinkage. Nws yog ib qho tseem ceeb kom ua raws li cov lus pom zoo los ntawm cov tuam txhab xws li Borida thiab siv tus nqi tsim nyog rau cov xwm txheej tshwj xeeb.

Borida, uas yog cov chaw tsim tshuaj paus nyob rau hauv Suav teb, muab ntau yam kev sib xyaw ua ke xws li retarders, plasticizers, superplasticizers, accelerators, thiab lwm yam.