Txhua tus xav tswj qhov zoo ntawm pob zeb. Qhov tseeb, qhov nyuaj tshaj plaws yog tias tsis muaj txoj hauv kev los pib tom qab siv tag nrho cov kev paub hauv phau ntawv. Nws tsis muaj txiaj ntsig los nug cov kws tshaj lij qub thaum ntsib teeb meem nyuaj. Nws yog ib qho nyuaj rau cov kws tshaj lij tsom mus rau qhov tseem ceeb ntawm qhov teeb meem yam tsis tau mus rau qhov chaw thiab hais lus dav dav. Los ntawm kev pom zoo, kev tswj xyuas qhov zoo ntawm pob zeb txhais tau tias tswj txhua qhov txuas thiab txheej txheem. Piv txwv li, yog tias qhov sib tov ua tiav zoo, tseem yuav muaj teeb meem. Qhov ntawd yog vim koj tsis tuaj yeem lav lwm qhov txuas. Tus tswv tsis yog tag nrho ntawm phau ntawv kev paub, tab sis muaj ntau yam kev paub. Qhov kev xav loj tshaj plaws ntawm ntau tus tswv yog tias nws nkag siab cov khoom ntawm ntau yam khoom siv raw, tsis yog tsuas yog superficially, tab sis kuj tseem me me cov ntsiab lus uas lwm tus tsis paub. Yog tias koj tsuas paub qhov kev paub ntawm cov ntaub ntawv uas nquag siv hauv phau ntawv, nws tsis txawv ntawm lwm tus. Nws tsis yooj yim rau kev siv cov khoom siv raw los npaj cov pob zeb ua kom tau raws li qhov yuav tsum tau ua. Piv txwv li, yog tias koj paub me ntsis txog ya tshauv tshaj lwm tus, nws muaj peev xwm ua kom zoo dua lwm tus. Thaum muaj teeb meem tshwm sim, lwm tus yuav Lub hauv paus kev paub tsis tiav, yog li koj tsis paub nws tom qab kev txiav txim siab ntau. Koj daws qhov teeb meem los ntawm kev xav txog cov ntsiab lus kev paub uas lwm tus tsis tau paub.
Plaub yam ntxwv ntawm cov cement hloov:
Feem ntau ntawm pob zeb yog cement. Cement yog ib qho tseem ceeb tshaj plaws uas cuam tshuam rau qhov zoo ntawm pob zeb. Tom qab lub hnub nyoog 28d, lub zog tsis nce, qhov kub ntawm hydration yog siab nyob rau hauv thaum ntxov theem, thiab lub cracking yog pom tseeb nyob rau hauv thaum ntxov theem. Cov no yog qee qhov teeb meem uas tib neeg tsis tuaj yeem nkag siab hauv cov cement siv hauv kev tsim cov pob zeb. Txawm hais tias muaj ntau yam cuam tshuam rau kev tswj kom zoo ntawm cov pob zeb, txij li xyoo 1920, los ntawm qhov kev xav ntawm kev txhim kho keeb kwm yav dhau los ntawm kev lag luam cement, txawm hais tias cov tsos ntawm cov cement tsis tau hloov pauv loj, cov ntxhia muaj pes tsawg leeg thiab lub zog ntawm cov cement tau hloov nrog kev hloov kho tshiab. ntawm kev lag luam cement. Cov kev hloov pauv loj tau tshwm sim, thiab cov kev hloov pauv no tau muaj kev cuam tshuam tseem ceeb rau kev tswj kom zoo ntawm cov pob zeb niaj hnub no. AM Neville tau taw qhia nyob rau hauv phau ntawv "Properties of concrete" (Fourth Edition) uas kev hloov ntawm cov cement tuaj yeem raug sau tseg hauv plaub lub ntsiab lus hauv qab no:
1. Cov ntsiab lus C3S tau nce ntau, thaum C2S cov ntsiab lus poob raws li
Wb tham txog UK. Xyoo 1960, C3S cov ntsiab lus tsuas yog kwv yees li 47 feem pua, thiab nyob rau xyoo 1970 nws tau los txog li 54 feem pua, thaum C2S cov ntsiab lus poob raws li, thiab tag nrho cov calcium silicate cov ntsiab lus tseem nyob li ntawm 70-71 feem pua, uas yog qhov pib tsis hloov. . Nyob rau nruab nrab -1960s hauv Fabkis, qhov nruab nrab C3S cov ntsiab lus ntawm Portland cement yog 42 feem pua, uas tau nce mus rau 58.4 feem pua hauv xyoo 1989, thaum C2S cov ntsiab lus poob ntawm 28 feem pua rau 13 feem pua ntawm tib lub sijhawm.
2. Lub zog ntawm cov cement mortar thaum ntxov nce
Lwm qhov tshwj xeeb yog tias lub zog ntawm cov cement mortar sib txawv heev, feem ntau vim hais tias lub zog 7d nrog cov dej ruaj khov sib piv nce ntxiv, thiab 28d lub zog kuj tseem txhim kho zoo heev. Txawm li cas los xij, lwm qhov ntsuas tseem ceeb tsis tau txhim kho, thiab qhov ntawd yog lub zog dhau ntawm 28d hnub nyoog. Peb paub tias nyob rau hauv 1970 dej-cement piv ntawm 0.50 yuav tsum tau ua kom tiav lub pob zeb ua lub zog ntawm 32.5MPa. Xyoo 1984, qhov sib piv ntawm dej-cement ntawm 0.57 yog xav tau. Ua kom cov dej siv ib lub cubic meter ntawm cov pob zeb ntawm tib 175kg / m3, piv txwv li kev ua haujlwm zoo ib yam, cov cement noj tau txo los ntawm 350kg / m3 mus rau 307kg / m3. Yuav kom nkag tau yooj yim dua los ntawm cov khoom siv carbonized lossis eroded, peb maj mam txais cov dej-cement piv thiab qis cov ntsiab lus cement kom cov pob zeb permeable. Nyob rau hauv txoj kev no, lub durability ntawm cov pob zeb dav dav yog qis dua. Qhov nce sai ntawm lub zog thaum ntxov kuj txhais tau hais tias lub zog formwork txaus tau ua tiav sai dua hauv cov pob zeb siv "laus" cement, yog li txwv tsis pub kev kho thaum ntxov. Yog li ntawd, kev ua tau zoo ntawm cov pob zeb tsis tuaj yeem txhim kho nyob rau lub sijhawm ntev.
3. Qhov piv ntawm cov cement mortar 28d lub zog rau 7d lub zog txo
Lub zog ntawm cov cement mortar nyob rau hauv thawj 28d lub hnub nyoog nce sai, ua rau txo qis ntawm qhov piv ntawm 28d lub zog rau 7d lub zog, uas yog vim qhov nce ntawm qhov sib piv ntawm C3S cov ntsiab lus rau C2S cov ntsiab lus, uas cuam tshuam los ntawm nws cov hydration tus nqi. . Qhov piv ntawm cov cement mortar 28d lub zog rau 7d lub zog zoo li qis dua ntawm cov dej-binder piv. Qhov kev xav empirical no ua rau muaj alkali ntau dua hauv cov cement niaj hnub. Txhua qhov chaw tsim khoom cement ntxiv alkali zais cia, thiab nws tsis kho. Nws yuav hloov tau ntxiv alkali raws li tus neeg siv khoom qhov xwm txheej thiab ua tau raws li cov neeg siv khoom xav tau. Xyoo 1923, lub zog compressive ntawm pob zeb yog linear nrog lub logarithm ntawm hnub nyoog mus rau 25 lossis 50 xyoo, uas yog qhov tshwm sim ntawm kev siv cov ntsiab lus siab C2S, tsis tshua muaj nplua nuj cement los tsim cov pob zeb. Xyoo 1937, kev sib raug zoo ntawm logarithmic ntawm compressive zog thiab hnub nyoog yog kwv yees li 10 xyoo, uas yog qhov tshwm sim ntawm kev siv cov ntsiab lus C2S tsawg, siab zoo cement los tsim cov pob zeb. Hauv xyoo tas los no, nrog kev sib raug zoo luv luv. Cov qauv no tuaj yeem pom los ntawm daim duab 3.
4. Kev txhim kho tsis tu ncua ntawm cov cement fineness
Txij li thaum kev lag luam cement tam sim no tau txais cov cuab yeej tsim khoom tshiab, uas yog qib siab dua yav dhau los, tshwj xeeb tshaj yog kev hloov kho tas mus li thiab kev nce qib ntawm cov cuab yeej sib tsoo tshiab, thaj chaw tshwj xeeb (fineness) ntawm cov cement tau nce tsis tu ncua. Nws yuav tsum tau taw qhia tias tam sim no peb feem ntau yog twv txiaj nrog qhov zoo ntawm cov pob zeb thiab peb tus kheej cov nyiaj hauv hnab tshos. Txhawm rau nce qhov chaw tshwj xeeb ntawm cov cement, ntau tus neeg xav tias yuav tsum tau txo cov nqi tsim khoom, uas kuj yog txoj hauv kev kom muaj sia nyob. Qhov no yog kev ua si mus sij hawm ntev. Kev nce qhov chaw tshwj xeeb ntawm cov cement tuaj yeem ua rau kom cov dej thaum ntxov thiab lub zog, yog li nce tus nqi ntawm cov cement, tab sis qhov no yuav ua rau muaj kev sib tsoo ntau dhau, thiab cov nqi tsim khoom yuav nce ntxiv. Yog li ntawd, cov tuam txhab cement tau mob siab rau siv tag nrho cov kev hloov kho tshiab ntawm cov cuab yeej tsim khoom thiab nrhiav kev sib npaug ntawm ob. Tam sim no muaj txoj hauv kev zoo, uas yog siv cov kev sib tsoo. Ntxiv cov khoom sib tsoo yog ib txoj hauv kev ntau lawm los ua kom cov cement zoo.
Tam sim no cov cement txawv heev ntawm cov cement 100 xyoo dhau los. Ntau cov cement uas twb muaj lawm muaj peev xwm siv tau siab C3S, qis C2S, thiab siab fineness kom ua tiav cov hom phiaj muaj zog thaum ntxov. Txawm hais tias siv "high-strength cement" tuaj yeem txo tus nqi ntawm cov cement nrog lub zog tshwj xeeb, ua kom cov formwork tshem tawm sai, thiab ua kom cov kev vam meej ntawm qhov project, kom cov neeg siv khoom siv dav dav tuaj yeem tau txais txiaj ntsig loj, tab sis cov dej siab- binder ratio thiab cov cement tsawg yuav yooj yim ua rau siab permeability ntawm pob zeb. Tsawg zog. Lub zog ntxov dhau thiab kev tso tseg ntxov ntxov ntawm kev saib xyuas zoo ntawm cov formwork kuj ua rau muaj kev nyab xeeb rau qhov zoo ntawm qhov project.
Lwm Cov Lus Nug:
1. Guarantee tus nqi ntawm cement lub zog
Mehta tau hais hauv "Concrete Microstructure, Performance and Materials" tias kev tswj hwm tus nqi zoo yuav tsum tau ua raws li cov txheej txheem txheeb cais, thiab cov khoom sib xyaw ua ke yuav tsum tau ua raws li qhov no. Kev ua tiav ntawm lub hom phiaj no yuav tsum yog raws li cov hauv qab no: Ua ntej, random sampling, kom ntseeg tau tias cov qauv yog random nyob rau hauv tus txheej txheem ntawm kev sau cov ntaub ntawv, tsis yog dag dag. Qhov thib ob yog los txais yuav lub tswb zoo li ib txwm faib nkhaus, raws li pom hauv daim duab 5.2-1A hauv qab no. Raws li kev txheeb cais, kev tswj xyuas tau zoo yog ua los ntawm kev tswj cov kab kos, uas graphically sawv cev rau cov txiaj ntsig tau txais hauv qhov kev sim txuas ntxiv. Thaum lub phiaj xwm nkhaus mus txog los yog tshaj qhov txwv sab sauv lossis qis hauv daim duab, nws qhia tau tias yuav tsum tau ua raws li kev ntsuas.
Yuav kom txais yuav txoj kev txheeb cais, tsis muaj luv luv, qhov no yog txoj kev xav tuag, leej twg ua nws, thiab ua kom zoo, tuaj yeem tswj tau lub zog ntawm cov cement. Rau cov tuam txhab tsim khoom me me, tsuas yog tswj lub zog ntawm 42.5 qib cement mortar ntau dua 42.5MPa, tus qauv sib txawv hloov pauv tau zoo heev, thiab qhov siab tshaj plaws tus nqi qis, uas pom tseeb deviates los ntawm txoj cai ntawm kev suav lej. Yog li ntawd, cov cement siv hauv kev tsim cov pob zeb yuav tsum xaiv cov chaw tsim khoom uas muaj lub zog lav zoo los tswj kev pheej hmoo los ntawm kev hloov pauv zoo.
2. Cement siv hauv kev ua haujlwm siab ua vaj tse
Raws li tau pom los ntawm cov lus hais saum toj no, kev lag luam cement tam sim no yog cov neeg muag khoom lag luam, thiab cov neeg tsim khoom siv cement passively. Nws yog ib qho tsim nyog los tawm tswv yim ntau qhov tsim nyog kev ua tau zoo rau cov tuam txhab cement los ntawm kev xav ntawm kev tsim vaj tsev ua vaj tse, txhawm rau daws qhov teeb meem ntawm kev ua tau zoo ntawm pob zeb los ntawm cov hauv paus hniav. Tsis txhob siv cov khoom siv cement ib zaug uas tau thov los ntawm cov tuam txhab cement, uas ua rau tsis muaj zog ntawm cov pob zeb thiab lwm yam teeb meem.
Cov "Cov Lus Qhia Txog Kev Siv Cov Khoom Siv Ua Haujlwm Zoo" ua ke los ntawm Ministry of Housing and Urban-Rural Development thiab Ministry of Industrialization Information tau teev tseg tias thaj chaw tshwj xeeb ntawm Portland cement thiab Portland cement zoo tib yam yuav tsum tsis pub tshaj 350m2 / kg; slag Portland cement, pozzolanic silica ntsev cement thiab ya tshauv Portland cement yog sawv cev los ntawm sieve residue, thiab lub sieve residue ntawm 80μm square qhov sieve tsis ntau tshaj 10 feem pua los yog lub sieve residue ntawm 45μm square qhov sieve tsis ntau tshaj 30 feem pua.
3. Qhov sib xyaw ntawm cov cement yog qhov nyuaj
Nyob rau hauv xyoo tas los no, cov thev naus laus zis cuam tshuam rau kev sib koom tes hauv tsev pov tseg thiab hauv nroog sludge hauv cov cement kiln tau dhau los ua kom paub tab. Nws ua lub luag haujlwm tseem ceeb hauv kev daws teeb meem hauv nroog thiab tsim kom muaj lub neej zoo hauv nroog. Txawm li cas los xij, lub hauv paus ntawm cov pov tseg hauv tsev yog qhov nyuaj, thiab cov ntsiab lus ntawm calcined tshauv kuj hloov pauv zoo heev. Yuav ua li cas los xyuas kom meej cov cement ntau lawm thiab siv cov pob zeb ntau lawm, tab sis tsis txhob deterioration ntawm compatibility ntawm cov cement thiab admixtures, yog ib qho teeb meem tsim nyog ntawm kev mloog.
Kev hloov ntawm cov cement yog maj mam, thiab nws yog ib qho tsim nyog yuav tsum nkag siab tag nrho nws cov kev hloov pauv thiab kev txhim kho txoj cai ntawm kev ua tau zoo, ua ke nrog cov yam ntxwv ntawm engineering, muab kev ua si tag nrho rau qhov zoo ntawm cov cement pob zeb.
