Thov tsis txhob cuam tshuam nrog cov pob zeb sib xyaw, tuaj thiab pom qhov tshwm sim
Dec 23, 2024
Concrete admixtures yog ib qho tseem ceeb ntawm cov pob zeb niaj hnub thiab ib txoj hauv kev tseem ceeb thiab kev siv tshuab rau kev hloov cov pob zeb. Lawv txhim kho lub cev thiab txhua yam khoom ntawm cov pob zeb tawv tawv, txhim kho qhov zoo thiab ruaj khov ntawm cov khoom siv hauv tsev, thiab tseem tuaj yeem txuag cov cement, txo cov nqi, thiab ua kom cov phiaj xwm ua tiav. Nrog rau txoj kev loj hlob ntawm kev tsim kho niaj hnub mus rau cov tsev siab siab thiab kev hloov mus rau kev npaj sib xyaw ua ke nrog kev sib xyaw hauv nruab nrab, kev siv cov pob zeb sib xyaw ua ke tau nce zuj zus. Txawm li cas los xij, kev siv cov khoom siv tsis raug yuav ua tsis tau raws li qhov xav tau thiab tej zaum yuav ua rau muaj teeb meem zoo.
Misconception 1: Siv Admixtures yam tsis tau kuaj
Ua ntej kev tsim kho vaj tse, kev tsim kho thiab kev saib xyuas feem ntau xa cov khoom xws li cement, xuab zeb, thiab cov khoom sib xyaw ua ke rau kev sim raws li cov qauv. Txawm li cas los xij, kev ua haujlwm ntawm cov khoom sib xyaw feem ntau tsis saib xyuas. Qhov tseeb, kev sib xyaw ua ke tuaj yeem muaj ntau yam, txhua tus nrog cov qauv zoo sib xws. Kev ua tau zoo ntawm cov khoom sib xyaw ncaj qha cuam tshuam rau nws lub luag haujlwm hauv pob zeb, xws li dej txo tus nqi thiab cov ntsiab lus chloride ion. Cov"Specification rau Kev Tsim Kho Zoo Txais Kev Tsim Kho Vaj Tse"(GB 50204), Clause 7.2.2, tshwj xeeb tshaj yog hais tias qhov zoo thiab kev siv technology ntawm admixtures hauv pob zeb yuav tsum ua raws li cov"Admixtures rau Concrete"(GB 8076),"Application Technical Code for Admixtures in Concrete"(GB 50119), thiab lwm yam kev tiv thaiv ib puag ncig. Nws kuj qhia txog tus naj npawb ntawm cov kev xeem thiab cov txheej txheem. Cov kab lus no yog qhov yuav tsum tau ua, thiab yog li ntawd, cov khoom sib xyaw yuav tsum tsis txhob siv rau hauv cov pob zeb tsis muaj kev sim.
Misconception 2: Siv Admixtures yam tsis xav txog cov kev xav tau tshwj xeeb
Admixture Xaiv Raws li Lub Hom Phiaj
Thaum xaiv cov khoom sib xyaw, nws yuav tsum ua raws li cov khoom siv engineering thiab kev tsim kho, txiav txim siab los ntawm kev sim sib xyaw ua ke. Txhua hom admixture muaj nws cov yam ntxwv, thiab nws yuav tsum tau xaiv raws li lub hom phiaj, xws li txuag cov cement, txhim kho kev ua tau zoo, lossis ua kom cov formwork nrawm dua. Kev sib piv kev sib piv kev lag luam thiab kev lag luam yuav tsum tau ua los txiav txim siab seb qhov twg yuav siv tau.
Kev soj ntsuam ntawm Admixture Daim Ntawv Thov rau ntau hom pob zeb
Waterproof Qhob: Lub hom phiaj ntawm kev siv admixtures nyob rau hauv waterproof qhob yog los txhim kho nws impermeability. Txhawm rau txhim kho impermeability, nws yog ib qho tseem ceeb kom txo tau cov pores sab hauv ntawm cov pob zeb thiab thaiv txoj kev to. Cov dej-txo cov neeg ua hauj lwm thiab cov cua-entraining agents feem ntau yog siv.
Cov pob zeb loj: Tus yuam sij rau kev tsim vaj tsev loj yog ua kom muaj kev sib raug zoo ntawm cov khaubncaws sab nraud povtseg ntawm cov pob zeb thaum pib, txo qhov kub thiab txias thaum lub sij hawm hardening txheej txheem, thiab tiv thaiv kev tawg. Siv lub retarding dej-reducer tuaj yeem ua tau raws li cov kev cai no los ntawm kev ua kom lub sij hawm qeeb thiab txo qhov kub thiab txias thaum lub sij hawm hardening, yog li txhim kho pob zeb zoo.
Prestressed Concrete Structures: Qhov kev txhawj xeeb tseem ceeb hauv qhov loj-span prestressed pob zeb ua qauv yog qhov hnyav ntawm cov qauv. Lub hom phiaj ntawm kev siv admixtures yog los npaj cov pob zeb ua kom muaj zog kom txo tau qhov hnyav ntawm cov qauv thiab siv cov kev ntxhov siab ntawm cov hlau uas muaj zog heev. Cov dej-txuas ua haujlwm siab yuav tsum raug xaiv kom txo qis kev siv dej thiab ua kom muaj zog ntxiv.
Misconception 3: Tsis quav ntsej qhov sib xws ntawm Admixtures thiab Cement
Dab tsi yog Compatibility ntawm Admixtures thiab Cement?
Lub compatibility ntawm admixtures thiab xis mas yuav piav raws li nram no: Thaum ib tug admixture, uas tau raug soj ntsuam thiab ua raws li cov qauv tsim, ntxiv rau cov pob zeb sib xyaw nrog cov cement uas ua tau raws li cov qauv tsim nyog rau hom admixture, nws yuav tsum tsim cov txiaj ntsig xav tau. . Yog tias qhov kev xav tau ua tiav, ces cov cement thiab admixture yog sib xws.
Piv txwv ntawm Incompatibility Ntawm Admixtures thiab Cement
Yuav luag txhua hom kev sib xyaw yuav muaj teeb meem kev sib raug zoo nrog cov cement. Piv txwv li, yog tias cov neeg ua haujlwm txo cov dej ua haujlwm siab (uas ua tau raws li cov qauv zoo) tau siv nrog ntau hom Portland cement zoo tib yam los npaj ua vaj tse nyob rau hauv tib qho kev sib xyaw, thiab ib hom cement ua rau txo qis dej ntau, nws txhais tau tias. cov cement yog incompatible nrog cov dej-reducer, thaum lwm yam cements ua hauj lwm zoo nrog tib admixture. Ib yam li ntawd, yog tias ib qho accelerator ntxiv rau cov cement sib tov tsis nrawm qhov teeb tsa, lossis yog tias tus retarder tsis qeeb lub sijhawm teem, nws qhia tias tsis sib haum ntawm cov khoom sib xyaw thiab cov cement. Piv txwv li, ntau hom dej-txuas yuav muaj qhov sib txawv ntawm cov cement dispersion, txo dej, thiab txhim kho; Qhov kev ua tau zoo tuaj yeem sib txawv nyob ntawm seb yam xws li cov cement ntxhia muaj pes tsawg leeg, cov khoom sib xyaw, cov ntsiab lus alkali, thiab hom gypsum. Qee cov cements yuav tsis sib haum nrog qee cov dej-txo, ua rau muaj teeb meem xws li kev teeb tsa tsis raug lossis teeb tsa sai.
Test Compatibility ntawm Admixtures thiab Cement
Qhov teeb meem kev sib raug zoo ntawm cov khoom sib xyaw thiab cov cement yog qhov nyuaj thiab tsis muaj kev zam, feem ntau cuam tshuam rau kev ua haujlwm thiab qee zaum ua rau muaj teeb meem loj hauv engineering thiab kev lag luam tsis txaus ntseeg. Ua ntej siv admixtures, qhov sib xyaw ua ke ntawm cov khoom sib xyaw thiab cov cement yuav tsum tau sim los ntawm kev tsim ib qho kev sib xyaw tsim thiab kos duab nkhaus nrog cov tshuaj sib xyaw ntawm cov kab rov tav axis thiab fluidity ntawm ntsug axis. Admixtures uas qhia tau hais tias tsis tshua muaj saturation point, siab fluidity, thiab kev poob nyiaj tsawg yog suav tias yog sib xws nrog cov cement.
Misconception 4: Ntau Admixture txhais tau tias zoo dua
Qhov tshwm sim ntawm kev siv cov khoom sib xyaw
Kev siv cov retarders ntau dhau tuaj yeem ua rau muaj kev cuam tshuam loj heev, muaj peev xwm tiv thaiv cov pob zeb los ntawm kev ua tiav qhov kawg ntawm lub sijhawm ntev. Kev siv ntau dhau kuj tuaj yeem ua rau cov ntsiab lus huab cua ntau ntxiv, ua rau poob ntawm cov pob zeb loj, thiab nyob rau hauv cov xwm txheej hnyav, ua rau lub zog qis dua qhov tsim nyog, ua rau muaj kev sib tsoo ntawm qhov project.
Kev siv ntau dhau ntawm cov dej-txhim hluav taws xob ntau dhau tuaj yeem ua rau huab cua npuas tsim, cuam tshuam thaum ntxov zog nce ntawm pob zeb.
Kev siv cov tshuaj chloride ntau dhau tuaj yeem txo cov pob zeb tiv thaiv kev tawm tsam tshuaj lom neeg thiab hnav, ua rau kom ntxov ntxov, thiab txo qis-thaw tsis kam thiab flexural zog.
Kev siv cov accelerator ntau dhau tuaj yeem ua rau lub sijhawm teem sijhawm thiab txo cov pob zeb loj hauv cov theem tom ntej.
Tsim nyog Admixture Dosage
Qhov tsim nyog npaum li cas ntawm cov khoom sib xyaw yog qhov tseem ceeb. Yog tias qhov ntau npaum li cas tsawg dhau, qhov nce hauv flowability yog tsawg; Yog tias qhov ntau npaum li cas siab dhau lawm, qhov flowability tsis nce proportionally. Qhov koob tshuaj zoo tshaj plaws yog qhov tseem ceeb rau kev ua tiav cov txiaj ntsig kev lag luam thiab nyiaj txiag. Qhov ntau npaum li cas muab nyob rau hauv cov khw muag khoom phau ntawv ua haujlwm ua ib qho kev siv, tab sis qhov zoo tshaj plaws yuav tsum tau txiav txim siab los ntawm kev sib tw sib tov.
Xaus:
Txhawm rau kom ua tiav qhov ua tau zoo ntawm cov khoom sib xyaw hauv cov pob zeb, cov hauv qab no yuav tsum tau ua:
Ua kom nkag siab qhov ntsuas qhov ua tau zoo ntawm cov khoom sib xyaw.
Xav txog qhov kev ua tau zoo ntawm cov pob zeb sib txuas rau qhov project tshwj xeeb thaum xaiv cov khoom sib xyaw.
Txiav txim siab ntau npaum li cas los ntawm kev sim sib xyaw.
