Admixture Cov ntsiab lus thiab kev siv dej

Qhov ntau npaum li cas ntawm admixture thiab tus nqi ntawm cov dej yog qhov tseem ceeb ntawm kev sib xyaw ua ke tsim. Lawv yog ob qho tib si antagonistic thiab kev sib koom ua ke, cuam tshuam thiab cuam tshuam nrog ib leeg. Tsuas yog los ntawm kev sib koom tes thiab sib npaug ntawm ob yam no tuaj yeem ua tiav cov pob zeb ua tiav. Hauv kev txiav txim siab txog cov xwm txheej no, yuav tsum tau saib xyuas lawv txoj kev sib koom tes. Cov khoom sib xyaw ua ke yuav tsum muaj qee qhov muab tshuaj txhuam kom ua tiav kev ua haujlwm txaus siab; Nws tsis yog ib txwm zoo dua los siv dej tsawg. Hauv kev sib xyaw tsim, yog tias cov khoom sib xyaw tsis txaus, nws yuav ua rau cov dej xav tau ntau ntxiv thiab ua rau cov pob zeb tsis zoo (tsis muaj dej tsis zoo, sib xyaw ua ke). Piv txwv li, yog tias cov kua nplaum ntau dhau thiab cov dej tsis txaus, cov pob zeb sib xyaw ua ke yuav nplaum, thiab txawm los ntshav. Tsis tas li ntawd, kev sib xyaw ua ke ntau dhau tuaj yeem ua rau cov pob zeb ua dej tsis zoo, ua rau cov khoom sib tov tsis yooj yim.

1. Kev siv tshuaj lom neeg

Nyob rau hauv cov xwm txheej uas cov cement, ntxhia admixtures, thiab aggregates yog tas mus li, muaj kev sib xyaw ua ke ntawm cov dej thiab cov tshuaj sib xyaw ua ke uas tuaj yeem ua rau cov cohesiveness, fluidity, thiab dej tuav ntawm cov pob zeb mus txog lub xeev zoo. Thaum siv cov khoom sib xyaw, qhov kev txiav txim siab ntau npaum li cas yuav tsum muaj qhov tso cai ntxiv kom ntseeg tau tias muaj kev nyab xeeb ntawm cov pob zeb ua haujlwm. Piv txwv li, yog tias qhov ntau npaum li cas ntawm cov tshuaj sib tov yog 2.2%, qhov ntau npaum li cas yuav tsum tau teem caij nyob ib ncig ntawm 1.8%, tso cai rau qhov chaw hloov kho ntawm 0.3%-0.5%.

Yog tias tus nqi dej tau txiav txim siab ua ntej thaum tsim kev sib xyaw, qhov kev siv tshuaj sib xyaw tuaj yeem raug soj ntsuam raws li tus nqi txo cov dej thiab tom qab ntawd lees paub los ntawm kev sim sib xyaw. Xwb, nrog rau cov nyiaj ruaj khov ntawm cov cement, cov ntxhia sib xyaw, thiab cov khoom sib xyaw ua ke, cov dej tuaj yeem pib kwv yees raws li cov kev xav tau ua haujlwm. Piv txwv li, yog hais tias qhov siab tshaj plaws tag nrho loj yog 31.5 hli, cov xuab zeb fineness modulus yog 2.6, thiab lub hom phiaj slump yog 180mm, cov dej theem pib yog 227.5kg / m³. Yog tias qhov sib xyaw ua ke yog 2.0% nrog cov dej txo qis ntawm 25%, cov dej rau cov pob zeb nrog cov khoom sib xyaw yog kwv yees li 170kg / m³.

Qhov ntau npaum ntawm admixture yog cuam tshuam tsis yog los ntawm qhov zoo ntawm cov cement tab sis kuj los ntawm qhov zoo ntawm cov ntxhia admixtures thiab aggregates. Rau ib qho kev sib xyaw ua ke ntawm cov ntaub ntawv, cov dej zoo tshaj plaws thiab cov khoom siv sib xyaw sib txawv thiab yuav tsum tau txiav txim siab los ntawm kev sim. Thaum lub sij hawm sim sib tov, cov txheej txheem muaj xws li kev faib tawm ntawm cov pob zeb sib xyaw ua ke, muab tshuaj txhuam tag nrho, txaus siab fluidity, tsis muaj los ntshav, thiab kev sib cais.

Yog tias qhov poob ntawm qhov sib tov loj dhau, ua rau los ntshav hnyav thiab sib cais, cov dej yuav tsum raug txo ua ntej thaum hloov kho. Yog tias qhov poob qis me ntsis dhau lawm, cov tshuaj sib xyaw tuaj yeem hloov kho li ntawm {{0}}.1%. Yog tias qhov poob qis me me dhau lawm, cov dej yuav tsum tau nce ntxiv raws li kev paub dhau los, vim tias cov dej nce ntxiv los ntawm 5kg / m³ tuaj yeem nce qhov poob ntawm 20mm. Qhov kev hloov pauv hauv kev poob qis nrog qhov nce ntawm 0.1% ntawm cov tshuaj sib xyaw ua ke yuav tsum tau txiav txim siab los ntawm kev sim, vim muaj ntau hom admixture thiab manufacturers qhia qhov sib txawv tseem ceeb.

Thaum cov tshuaj sib tov yog tsau, muaj cov dej tseem ceeb. Yog tias cov dej ntau tshaj qhov nqi no, qhov sib xyaw ua ke yuav yooj yim cais thiab los ntshav. Thaum tus nqi dej nyob ze rau qhov tseem ceeb no, kev hloov me me ntawm cov dej tuaj yeem ua rau muaj kev hloov pauv tseem ceeb hauv lub xeev ntawm cov pob zeb sib xyaw, ua rau muaj kev cuam tshuam rau kev tswj kom zoo. Kev hloov pauv ntawm cov dej noo ntawm cov khoom sib xyaw tuaj yeem ua yuam kev tshwm sim yog qhov teeb meem kev sib xyaw ua ke, tab sis nws yog qhov teeb meem tsim qauv sib xyaw.

2. Tus nqi dej

Cov txheej txheem dej sib xws ntawm cov cement, cov dej xav tau ntawm ya tshauv, thiab qhov sib piv ntawm cov ntxhia hauv cov ntxhia sib xyaw tag nrho cuam tshuam rau cov dej ntawm cov pob zeb. Txawm li cas los xij, qhov cuam tshuam ntawm pob zeb poob rau ntawm cov dej yog qhov ncaj tshaj plaws. Txawm hais tias kev siv cov khoom sib xyaw decouples slump loj los ntawm dej npaum li cas, tso cai slump hloov los ntawm kev hloov admixture dosage thaum khaws cov dej tsis tu ncua, qhov loj me me uas yuav tsum tau muaj dej tsawg tuaj yeem ua rau tsis txaus. Tsuas yog nce cov tshuaj sib xyaw kom ua tiav kev ua haujlwm txaus siab tuaj yeem ua rau muaj kev sib cais thiab los ntshav. Nrog rau qhov sib npaug ntawm cov cement, ntxhia admixtures, thiab aggregates, muaj qhov tsawg kawg nkaus dej kom ua tiav qhov kev xav tau poob qis, hauv qab uas cov khoom siv tsis tuaj yeem ua tau zoo.

Deterioration nyob rau hauv raw khoom zoo yuav txo tau cov compatibility nrog admixtures, txo cov dej txo tus nqi. Thaum lub sijhawm tsim khoom, cov khoom siv raw yuav tsum tau hloov pauv, thiab tus nqi dej tswj tau siv cov khoom sib xyaw es tsis yog tsuas yog nce dej kom txhim kho kev ua haujlwm. Qhov no yog qhov tseeb tshwj xeeb tshaj yog rau polycarboxylate superplasticizers, uas yog rhiab heev rau cov xuab zeb thiab pob zeb hmoov cov ntsiab lus nyob rau hauv aggregates.

3. Kev txiav txim siab ntawm tus nqi dej thiab cov khoom siv sib xyaw

Rau cov dej npaum li cas, txoj cai qis tshaj dej-cement ratio yuav tsum tau ua raws li. Txoj cai no hais tias cov dej yuav tsum raug txo kom tsawg thaum ua tau raws li qhov yuav tsum tau ua. Cov dej ntau ua rau muaj qhov porosity ntxiv, dej nqus dej, permeability, txo cov dej tsis zoo, nce shrinkage tawg, txo cov aggregate-cement interface bonding, txo rebar-grout tuav, ntau dua ntim hloov vim ntub-qhuav cycles, thiab txo tsis kam rau huab cua thiab tshuaj tua kab mob. Ua raws li txoj cai muab tshuaj txhuam yam tsawg kawg nkaus kuj tseem ceeb. Muab tshuaj txhuam ntau dhau cuam tshuam qhov ntim ruaj khov, ua kom tawg tawg; paste tsawg dhau yuav txo cov txheej txheej tuab, txo cov fluidity thiab durability.