Raw cov ntaub ntawv thiab sib tov piv ntawm shotcrete pob zeb
Aug 13, 2024
1. Raw Material Requirements rau Shotcrete
Shotcrete yuav tsum siv cov khoom sib xyaw uas ua tau raws li qhov yuav tsum tau ua. Xaiv cov khoom siv ceev ceev uas sib haum nrog cov cement, muaj qhov ceev thiab lub sij hawm hardening, tsawg kawg 28- hnub lub zog poob, thiab yuav tsum tau noj tsawg. Ua ntej siv, kev sib raug zoo ntawm tus neeg sawv cev ceev ceev nrog cov cement thiab kev teeb tsa ntawm cov cement paste yuav tsum tau sim. Thaum siv ua ke nrog lwm hom kev sib xyaw, cov kev ntsuas ua tau zoo yuav tsum tau ua. Cov hmoov ua kom nrawm nrawm yog cov hygroscopic heev thiab ua rau muaj kev puas tsuaj, yog li lawv yuav tsum tau qhuav thaum lub sij hawm thauj mus los thiab cia, nrog rau cov ntim kom tsis txhob ya raws kev nqus, caking, los yog degradation.
Txhawm rau kom muaj kev teeb tsa sai sai thiab txhim kho 1-hnub lub zog, qhov tseem ceeb yuav tsum tau muab rau kev siv Portland cement lossis Portland cement. Rau kev tiv thaiv corrosion lossis lwm yam kev cai tshwj xeeb, cov cement tshwj xeeb kuj tuaj yeem siv tau. Cov qib cement zog yuav tsum tsis txhob qis dua 42.5.
Cov dej siv rau kev txhaj tshuaj yuav tsum ua raws li cov kev cai ntawm "Standard for Mixing Water in Concrete" (JGJ63-89). Cov dej yuav tsum tsis txhob muaj teeb meem impurities uas cuam tshuam rau qhov qub chaw thiab hardening ntawm cov cement. Nws yog txwv tsis pub siv cov dej phwj tuaj, cov dej acidic uas muaj pH tsawg dua 5, lossis cov dej uas muaj sulfate ntau dua 1%.
2. Sib tov qhov yuav tsum tau ua rau txhaj tshuaj
Lub zog yuav tsum ua tau raws li cov qauv tsim. Rau ntub-sib xyaw shotcrete, qhov slump yuav tsum tau tswj ntawm 80mm thiab 120mm, ua tau raws li cov kev xav tau ntawm engineering rau Frost, impermeability, thiab durability, thaum tseem txo qis kev siv cement. Qhov sib xyaw ua ke yuav tsum tau txiav txim siab los ntawm kev sim tshuaj tsuag lossis raws li kev paub dhau los.
Nyob rau hauv qhuav-mix shotcrete, qhov loj piv ntawm cov cement rau aggregate yuav tsum yog 1: 4.0 rau 1: 4.5; cov dej-cement piv yuav tsum yog 0.40 rau 0.45; cov xuab zeb piv yuav tsum tau tswj nyob rau hauv thaj tsam ntawm 45% mus rau 55%. Cov dej-cement piv feem ntau yog tswj los ntawm tus neeg teb xov tooj raws li kev paub dhau los. Txawm hais tias nws yog ib qho nyuaj kom ua tau raws li qhov sib xws, nws yuav tsum tau hais tias thaum lub sij hawm txau, cov plua plav thiab rov qab yog tsawg, qhov chaw txhaj tshuaj yog tus du nrog lub ntsej muag ci, thiab tsis muaj qhov qhuav los yog slippage.
Nyob rau hauv ntub-mix shotcrete, qhov loj piv ntawm cov cement rau aggregate yuav tsum yog 1: 3.5 rau 1: 4.0; cov dej-cement piv yuav tsum yog 0.42 rau 0.50; cov xuab zeb piv yuav tsum tau tswj nyob rau hauv thaj tsam ntawm 50% mus rau 60%.
Thaum txhaj tshuaj yog thawj zaug siv rau lub substrate, nws tsuas yog nyob ntawm kev sib koom ua ke los ntawm cov cement paste thiab mortar. Yog li ntawd, cov ntsiab lus ntawm cov cement yuav tsum tsis txhob qis dhau, thiab cov xuab zeb sib piv yuav tsum siab heev. Feem ntau, cov ntsiab lus cement yog nyob ib ncig ntawm 400kg / m³, thiab cov xuab zeb sib piv yuav tsum tau tswj ntawm 45% thiab 60%. Txawm li cas los xij, qhov sib piv ntawm cov xuab zeb siab tuaj yeem ua rau tawg yooj yim hauv kev txhaj tshuaj nyob rau hauv cov xwm txheej ntawm cov cua muaj zog, qhuav cua sov, thiab raug. Yog li ntawd, thaum lub sij hawm txhaj tshuaj tiv thaiv, ib puag ncig tej yam kev mob yuav tsum tau xav txog, nrog rau cov kev cai rau rebound tus nqi thiab kev tiv thaiv tawg. Nyob rau hauv qhov chaw ntawm tsis nce tus nqi rov qab, yuav tsum tau xaiv cov xuab zeb qis.
Shotcrete yuav tsum siv cov pob zeb nyuaj thiab ruaj khov los yog cov pob zeb crushed, nrog rau qhov loj tshaj qhov sib sau tsis pub tshaj 15 hli. Thaum siv fiber ntau-inforced shotcrete, qhov siab tshaj plaws aggregate loj yuav tsum tsis txhob ntau tshaj 10mm. Vim lub siab alkalinity feem ntau muaj nyob rau hauv cov neeg ua hauj lwm ceev ceev, alkaline active aggregates yuav tsum tsis txhob siv thaum alkaline ceev-setting agents. Qhov zoo sib sau ua ke rau kev txhaj tshuaj yuav tsum yog cov tawv thiab ruaj khov nruab nrab-coarse xuab zeb, nrog rau kev ua kom zoo ntawm kev tswj ntawm 2.5 thiab 3.5. Nyob rau hauv qhuav-mix shotcrete, cov av noo ntawm cov xuab zeb yuav tsum tau tswj nyob rau hauv thaj tsam ntawm 5% mus rau 7%; Thaum siv lub tshuab tshuaj tiv thaiv nplaum, cov xuab zeb noo noo tuaj yeem yog 7% mus rau 10%. Kev sib xyaw ua ke ntawm cov ntxhib thiab nplua zoo sib sau ua ke yuav tsum ua raws li cov cai teev tseg hauv Table 2.
Table 2: Sib Nqus pawg feem pua Kev faib tawm ntawm Coarse thiab Fine Aggregates dhau los ntawm Ntau Yam Sieve Loj rau Shotcrete (%).
| Sieve Loj (mm) | 0.15 | 0.30 | 0.60 | 1.20 | 2.50 | 5.00 | 10.00 |
15.00 |
| Zoo heev | 5–7 | 10–15 |
|
23–31 | 34–43 | 50–60 |
78–82 | 100 |
| Zoo | 4–8 | 5–22 | 13–31 | 18–36 | 24–54 | 40–70 | 62–90 | 100 |
Lus Cim: Lub voj voog sieves yog siv rau hauv lub rooj.
Qhov ntau npaum li cas ntawm tus neeg saib xyuas ceev yuav tsum yog 2% mus rau 8% ntawm cov cement loj, nrog rau qhov kev pom zoo tau txiav txim siab los ntawm kev ntsuam xyuas raws li hom kev siv ceev ceev.
Thaum cov fibers ntxiv rau shotcrete, tshwj tsis yog cov hlau fibers, uas txhim khu lub zog tensile, feem ntau cov organic fibers tsuas yog pab tiv thaiv kev tawg. Yog li, qhov ntau npaum li cas thiab qhov sib xyaw yuav tsum tau txiav txim siab los ntawm kev sim sib xyaw thiab sim tshuaj tsuag.
