Kev thov thiab cuam tshuam ntawm tus neeg sawv cev nthuav dav hauv pob zeb

I. Muaj nuj nqi ntawm cov pob zeb nthuav dav

1. Tiv thaiv kev tawg

Ntxiv qhov tsim nyog ntawm tus neeg sawv cev nthuav dav rau pob zeb tuaj yeem tiv thaiv qhov tshwm sim ntawm cov kab nrib pleb.

2. Waterproofing

Vim tias kev siv cov khoom siv nthuav dav ua rau muaj kev ntxhov siab nthuav dav, lawv tuaj yeem muab qee theem ntawm cov dej tsis zoo, tso cai rau cov pob zeb siv rau hauv qhov chaw ntub dej.

3. Shrinkage Compensation

Concrete expanding agents tuaj yeem them rau qhov shrinkage, ua kom cov pob zeb ruaj khov hauv kev ua haujlwm.

II. Yuav Siv Concrete Expanding Agents li cas

1. Nyeem cov lus qhia

Ua ntej siv tus neeg sawv cev nthuav dav, ua tib zoo nyeem cov lus qhia thiab tom qab ntawd sib tov rau hauv cov pob zeb ua raws li qhov piv txwv. Cov npe sib txawv ntawm cov neeg sawv cev sib txawv muaj qhov ntsuas qhov sib txawv, yog li txhawm rau ua kom tus neeg sawv cev ua haujlwm tau zoo, nws yuav tsum tau ntxiv nruj me ntsis raws li qhov piv txwv.

2. Kev Tswj Kub Kub

Tom qab sib tov cov pob zeb nrog tus neeg sawv cev nthuav dav, ncuav nws mus rau hauv pwm. Qhov kub ntawm ib puag ncig yuav tsum tau tswj nyob ib ncig ntawm 30 degree. Yog tias cov xwm txheej tsis tso cai, qhov sib txawv ntawm ± 5 degree tau txais thiab yuav tsis cuam tshuam rau kev ua haujlwm.

3. Kev vibration Compaction

Thaum cov pob zeb nyob rau hauv pwm, siv lub vibrator kom compact nws. Nws yog ib qho tseem ceeb uas cov pob zeb yog ntau compact dua li cov pob zeb zoo tib yam kom ua tiav qhov kev xav tau ntawm cov dej tsis muaj dej thiab cov nyiaj shrinkage.

4. Kho

Tom qab vibrating, lub pob zeb yuav tsum tau kho kom zoo rau li 14 hnub. Thawj 7 hnub xav tau kev saib xyuas ntau dua, nrog rau cov dej hauv ib hnub tsis pub tsawg tshaj tsib zaug, tshwj xeeb tshaj yog thaum 10 teev sawv ntxov txog 4 teev tsaus ntuj thaum kub siab dua. Rau qhov seem 7 hnub, raws li cov pob zeb nce mus txog qhov pib, watering ob zaug ib hnub (sab sawv ntxov thiab yav tav su) yog txaus.

III. Cov teebmeem ntawm Expanding Agents rau pob zeb

Expanding agents yog additives uas ua rau me ntsis ntim expansion hauv pob zeb, feem ntau los them rau cov pob zeb shrinkage thiab tsim kom muaj kev ntxhov siab rau tus kheej. Yog li ntawd, qhov tseem ceeb tshaj plaws ntawm cov pob zeb nthuav dav yog tsim cov micro-expansion hauv cov pob zeb, uas pab tshem tawm cov kab nrib pleb, muab cov dej tsis muaj dej, sau cov pores, thiab txhim kho compactness ntawm pob zeb.

1. Qhov cuam tshuam rau cov pob zeb tshiab

(1) Flowability

Ntxiv cov neeg sawv cev nthuav dav rau cov pob zeb txo nws txoj kev ntws mus rau qhov sib txawv. Nyob rau tib lub slump, cov dej-cement piv ntawm cov pob zeb nrog nthuav cov neeg sawv cev yuav tsum loj dua, ua rau cov slump poob. Qhov no yog vim hais tias cov txheej txheem hydration muaj kev sib tw rau cov dej ntawm cov cement thiab cov neeg sawv cev nthuav dav, txo cov slump thiab nce qhov poob.

(2) Ntshav

Qhob nrog cov neeg ua kom nthuav dav muaj cov ntshav qis dua piv rau cov pob zeb uas tsis muaj cov kab mob nthuav dav, txawm tias qhov sib txawv tsis tseem ceeb heev.

(3) Teem sijhawm

Thaum sulfate-aluminate expanding agents raug ntxiv, cov tshuaj tiv thaiv thaum ntxov ntawm sulfate-aluminate thiab cement ua rau cov txheej txheem hydration, yog li shortening lub sij hawm ntawm cov pob zeb.

2. Qhov cuam tshuam rau Hardened Qhob

(1) Compressive zog

Lub zog thaum ntxov ntawm pob zeb txo qis nrog qhov sib ntxiv ntawm cov neeg sawv cev nthuav dav, tab sis tom qab lub zog loj hlob sai. Nyob rau hauv zoo curing tej yam kev mob, lub compactness ntawm qhob nce, thiab qhov tsim nyog tus nqi ntawm expanding tus neeg sawv cev yuav ua rau lub compressive zog ntawm cov pob zeb ntau tshaj li cov pob zeb tsis muaj expanding agents. Txawm li cas los xij, yog tias tus neeg sawv cev nthuav dav ntxiv ntau dhau lawm, lub zog compressive yuav txo qis vim kev nthuav dav ntau dhau.

Kev xyaum ua vaj tse tau pom tias nyob rau hauv cov xwm txheej txwv, pob zeb nrog cov neeg sawv cev nthuav dav feem ntau nthuav tawm kev txhim kho compressive zog piv rau cov pob zeb uas tsis muaj cov neeg sawv cev nthuav dav.

(2) Impermeability

Thaum lub sij hawm hydration, expanding agents ua rau pob zeb nthuav me ntsis, ua cov khoom hydration zoo li ettringite, ib rab koob zoo li siv lead ua. Raws li hydration zuj zus, ettringite crystals interconnect los tsim ib lub network qauv, thaiv qhov khoob hauv cov cement matrix thiab txiav tawm cov kab capillary, yog li txo qis permeability thiab txhim kho impermeability ntawm pob zeb.

(3) Frost Resistance

Kev xyaum ua vaj tse tau pom tias ntxiv cov neeg sawv cev nthuav dav txo cov pob zeb tawg, ua kom cov compactness, thiab zoo heev txhim kho cov Frost tsis kam thiab durability ntawm pob zeb.

(4) Shrinkage Compensation thiab Crack Resistance

Pob zeb nthuav dav cov neeg ua haujlwm txhawm rau tiv thaiv kev tawg thiab txhim kho kev tawg. Thaum ntxov hardening theem, micro-expansion tshwm sim, ua rau nws tus kheej-kev nyuaj siab ntawm 0.2-0.7 MPa. Qhov no micro-expansion nyhuv stabilizes nyob ib ncig ntawm 14 hnub, ncua lub shrinkage txheej txheem. Txhim kho tom qab lub zog ntawm cov pob zeb ua kom muaj zog tiv thaiv tensile kev nyuaj siab, thaum shrinkage them nyiaj txo qis qhov tshwm sim ntawm kev tawg, txhim kho kev tawg.