Kev sib xyaw ua vaj tse koj tus kheej tsis yog qhov nyuaj - tsuav yog paub qhov sib xyaw kom raug. Cov no nyob rau hauv lem nyob ntawm seb yuav tsum tau concreted. Puas yog cov pob zeb tom qab tsuas yog raug rau cov neeg kho tshuab kev ntxhov siab lossis nws puas yuav tsum tau tiv thaiv Frost thiab tshuaj cuam tshuam? Txhawm rau kom ua tiav qhov txiaj ntsig zoo, qhov sib piv ntawm tus kheej cov khoom yuav tsum tau ua kom zoo sib xws.
Mixture
Qhob muaj peb yam: cement, dej thiab thiaj li hu ua aggregate. Cov aggregate yog xuab zeb, gravel los yog grit. Koj tuaj yeem ntxiv cov xim lossis cov xim rau cov khoom sib xyaw no thiab siv lawv los pleev xim rau pob zeb / cement.
Qhov piv ntawm cov cement thiab aggregate yog 1: 4. Yog li cov pob zeb muaj ib feem ntawm cov cement thiab plaub qhov sib sau ua ke. Ntxiv rau qhov no yog dej. Txawm li cas los xij, ntxiv dej ntau npaum li cas nyob ntawm chav kawm raug. Qhov no qhia tau hais tias muaj zog npaum li cas thiab qhov ua vaj tse yuav raug rau tom qab. Txawm li cas los xij, tus nqi dej kuj tuaj yeem xam tau yooj yim.
Density thiab quantity
Concrete muaj qhov ceev nruab nrab ntawm 2.4 mus rau 2.5 kg/dm³ (kilograms per cubic decimeter). Rau ib lub ntim ntawm ib lub cubic meter, yuav tsum tau 2,400 mus rau 2,500 kg ntawm pob zeb. Los ntawm qhov no koj tuaj yeem xam cov nqi ntawm cov cement xav tau yooj yim.
pob zeb muaj ib feem ntawm cov cement thiab plaub feem sib sau los yog ib feem tsib cement. Tag nrho cov pob zeb yuav tsum tau tsuas yog muab faib los ntawm tsib kom tau txais qhov yuav tsum tau ntawm cov cement. Rau ib lub cubic meter qhov no txhais tau tias:
- 2400 kg / 5=480 kg
- 2500 kg / 5=500 kg
Rau ib qhocubic meter ntawm pob zeb,480 txog 500 kg ntawm cement yog xav tau.
Tau kawg, kev suav kuj tuaj yeem ua rau lwm qhov kev taw qhia kom suav cov pob zeb ntau npaum li cas los ntawm cov cement uas twb muaj lawm. Ua li no, tus nqi ntawm cov cement tsuas yog muab faib ua tsib. Qhov no ua rau muaj qhov ntim loj ntawm 25 kg ntawm cement:
25 kg cement x 5=125 kg qhob
W/C tus nqi
Tus nqi W/C qhia tias yuav tsum tau muab dej ntau npaum li cas ntxiv rau cov cement thiab cov sib sau ua ke kom tau txais cov txiaj ntsig zoo tshaj plaws. Tus nqi yog nyob ntawm seb qhov kev ntxhov siab thiab ib puag ncig cuam tshuam rau qhov ua vaj tse tom qab yuav tsum tau tiv thaiv. Tus nqi W/C yog raws li hauv qab no:
Mechanical Hnav
- Hlub heev 0,40
- Zoo 0, 45
- Medium 0.55
Frost
- Ntawm dej siab 0,50
- Ntawm dej nruab nrab saturation 0,60
Chemical influences
- Weak 0, 60
- Medium 0, 50
- Zoo 0, 45
Cuas ratios
Txhawm rau xam qhov xav tau ntawm cov cement, sib sau ua ke thiab dej, tag nrho cov nyiaj uas xav tau hauv kilograms yuav tsum tau suav ua ntej. Ua li no, lub ntim yog thawj zaug xam los ntawm kev muab qhov ntev, qhov dav thiab qhov siab ua ke. Piv txwv li, yog hais tias ib txoj kev ib 'meter' dav thiab kaum meters ntev yuav tsum tau them nrog ib tug kaum centimeter tuab txheej ntawm pob zeb, lub pob zeb ntim yuav tsum tau:
- 10 square metres x 0.1 meter (qhov siab lossis thickness ntawm cov pob zeb txheej)=1 cubic meter
Luas=10 m² x 10 m²=10 m²
Vim qhov nruab nrab loj ntawm 2,450 kg ntawm qhob ib cubic meter, 2,400 mus rau 2,500 kg ntawm qhob yuav tsum tau. Qhov no nyob rau hauv lem ua rau qhov xav tau rau cement ntawm:
2,500 kg pob zeb / 5=500 kg cement (20 hnab ntawm 25 kg txhua)
Rau qhov nyiaj ntxiv, tag nrho cov pob zeb tau muab faib ua 4/5 lossis 0.8 lossis qhov sib txawv ntawm tag nrho cov nyiaj thiab pob zeb siv.
- 2,500 kg qhob x 0.8=2,000 kg surcharge
- 2,500 kg pob zeb - 500 kg cement=2,000 kg surcharge
Thaum kawg, tus nqi dej yuav tsum tau suav nrog tus nqi W/C. Piv txwv li, yog tias cov pob zeb raug cuam tshuam rau cov neeg kho tshuab muaj zog, tus nqi W / C yog 0.40. Qhov piv ntawm cov cement thiab dej yog xam los ntawm kev sib piv yooj yim:
500 kg cement x 0.40 W/C tus nqi=200 litres dej
Rau qhov piv txwv tau muab nrog rau qhov ntau ntawm 2,500 kilograms ntawm qhob, 500 kg ntawm cement, 2,000 kg ntawm tag nrho thiab 200 liters dej.
Cov nqi
Rau tus qauv ntim loj ntawm 25 kg ntawm cement, koj yuav tsum cia siab tias tus nqi ntawm 3 txog 6 euros. Rau cov piv txwv saum toj no, yuav tsum tau 500 kg ntawm cement. Cov nqi rau qhov no suav nrog hauv qab no:
- 500 kg tag nrho / 25 kg hnab=20 hnab cement
- 3€ ib hnab x 20 hnab=60€
- 6 euros ib hnab x 20 hnab=120 euros
Tus nqi nruab nrab tuaj yeem nyob nruab nrab ntawm60 thiab 120 euros.
Tsis tas li ntawd, muaj cov nqi rau cov nqi ntxiv. Nyob ntawm qhov loj me, koj tuaj yeem cia siab tias 30 txog 50 euros ib tuj rau pob zeb pob zeb, chippings thiab xuab zeb, uas ua rau tus nqi ntawm 60 txog 100 euros rau cov piv txwv suav.
Cov khoom siv raw yuav tsum yog li tus nqi120 txog 220 euros
Nws yuav tsum tau muab sau tseg tias kev xa khoom feem ntau siab dua tus nqi ntawm cov cement thiab cov nqi ntxiv vim qhov hnyav hnyav. Cov ntaub ntawv no tsis yog tus nqi tag nrho.
