Hnub Kawg: 26 Lub Kaum Ob Hlis, 2022
1. Dej-txo cov khoom sib xyaw
Cov dej-txo cov khoom siv yog cov khoom siv tshuaj uas thaum ntxiv rau hauv cov pob zeb tuaj yeem tsim qhov kev xav tau ntawm qhov qis dej-cement piv dua li qhov nws ib txwm tsim. Cov dej-txo cov khoom siv yog siv kom tau txais cov pob zeb tshwj xeeb uas siv cov ntsiab lus qis qis. Cov ntsiab lus ntawm cov cement qis ua rau qis qis CO2 emissions thiab kev siv zog rau ib qhov ntim ntawm cov pob zeb ua. Nrog rau hom admixture no, cov cuab yeej ua vaj tse tau txhim kho thiab pab muab cov pob zeb ua rau hauv cov xwm txheej nyuaj. Cov dej reducers tau siv feem ntau hauv cov choj decks, qis-slump qhob overlays, thiab patching pob zeb. Kev nce qib tsis ntev los no hauv kev siv thev naus laus zis tau ua rau kev txhim kho ntawm cov dej hauv nruab nrab.
2. Concrete Admixtures: Superplasticizers
Lub hom phiaj tseem ceeb ntawm kev siv cov khoom siv superplasticizers yog tsim cov pob zeb uas ntws nrog qhov poob siab hauv qhov ntau ntawm xya mus rau cuaj ntiv tes los siv rau hauv cov qauv siv zog hnyav thiab nyob rau hauv qhov chaw uas muaj kev sib koom ua ke los ntawm kev co tsis tuaj yeem ua tiav. Lwm daim ntawv thov tseem ceeb yog kev tsim cov pob zeb muaj zog ntawm w / c's xws li 0.3 txog 0.4. Nws tau pom tias rau ntau hom cement, superplasticizer txhim kho kev ua haujlwm ntawm pob zeb. Ib qho teeb meem cuam tshuam nrog kev siv cov dej ntau ntau hauv cov pob zeb yog qhov poob qis. Kev ua haujlwm siab ua pob zeb uas muaj superplasticizer tuaj yeem ua kom muaj kev tiv thaiv siab khov-thaw, tab sis cov ntsiab lus huab cua yuav tsum tau nce ntxiv rau cov pob zeb tsis muaj superplasticizer.
3. Concrete Admixtures: Teem-Retarding
Teem retarding qhob admixtures yog siv los ncua cov tshuaj tiv thaiv uas tshwm sim thaum lub pob zeb pib txheej txheem teeb tsa. Cov hom kev sib xyaw ua ke no feem ntau yog siv los txo cov txiaj ntsig ntawm qhov kub thiab txias uas tuaj yeem tsim qhov chaw pib sai ntawm cov pob zeb. Teem caij retarding admixtures yog siv rau hauv kev tsim vaj tse pob zeb, tso cai rau ntau lub sijhawm rau kev ua tiav cov pob zeb ua pob zeb, txo cov nqi ntxiv los tso cov pob zeb tshiab rau ntawm qhov chaw ua haujlwm thiab pab tshem tawm cov pob qij txha hauv pob zeb. Retarders kuj tuaj yeem siv los tiv thaiv kev tawg vim daim ntawv deflection uas tuaj yeem tshwm sim thaum kab rov tav slabs muab tso rau hauv ntu. Feem ntau cov retarders kuj ua haujlwm raws li cov dej txo qis thiab tuaj yeem nkag tau qee qhov cua hauv pob zeb
4. Concrete Admixtures: Air-Entraining Agent
Cua entraining qhob yuav ua rau kom khov-thaw durability ntawm pob zeb. Hom admixture no ua rau cov pob zeb ua haujlwm tau zoo dua li cov pob zeb uas tsis yog entrained thaum txo cov ntshav thiab kev sib cais ntawm cov pob zeb tshiab. Txhim kho kev tiv thaiv ntawm pob zeb rau qhov ua rau Frost hnyav lossis khov / thaw mus. Lwm cov txiaj ntsig los ntawm cov khoom sib xyaw no yog:
ib. Siab tiv taus rau lub voj voog ntawm ntub thiab ziab
b. High degree ntawm kev ua haujlwm
c. High degree ntawm durability
Cov npuas cua nkag mus ua lub cev tsis muaj zog tiv thaiv kev tawg los ntawm kev ntxhov siab vim dej ntim augmentation hauv qhov kub thiab txias. Cua entertaining admixtures yog sib xws nrog yuav luag tag nrho cov qhob admixtures. Feem ntau rau txhua ib feem pua ntawm cov cua nkag, compressive zog yuav raug txo los ntawm tsib feem pua.
5. Concrete Admixtures: Accelerating
Shrinkage-txo cov qhob admixtures yog ntxiv rau pob zeb thaum pib sib tov. Hom admixture no tuaj yeem txo qis thaum ntxov thiab mus sij hawm ntev kom qhuav shrinkage. Shrinkage txo admixtures tuaj yeem siv rau hauv cov xwm txheej uas shrinkage cracking tuaj yeem ua rau muaj teeb meem ua haujlwm ntev lossis qhov chaw loj ntawm cov pob qij txha tsis zoo rau kev lag luam lossis kev lag luam. Shrinkage txo admixtures tuaj yeem, qee zaum, txo qhov kev loj hlob ntawm lub zog thaum ntxov thiab tom qab hnub nyoog.
6.Concrete Admixtures: Shrinkage txo
Shrinkage-txo cov qhob admixtures yog ntxiv rau pob zeb thaum pib sib tov. Hom admixture no tuaj yeem txo qis thaum ntxov thiab mus sij hawm ntev kom qhuav shrinkage. Shrinkage txo admixtures tuaj yeem siv rau hauv cov xwm txheej uas shrinkage cracking tuaj yeem ua rau muaj teeb meem ua haujlwm ntev lossis qhov chaw loj ntawm cov pob qij txha tsis zoo rau kev lag luam lossis kev lag luam. Shrinkage txo admixtures tuaj yeem, qee zaum, txo qhov kev loj hlob ntawm lub zog thaum ntxov thiab tom qab hnub nyoog.
7. Concrete Admixtures: Corrosion-Inhibiting
Corrosion-inhibiting admixtures poob rau hauv tshwj xeeb admixture qeb thiab yog siv los qeeb corrosion ntawm reinforcing steel hauv pob zeb. Corrosion inhibitors tuaj yeem txo cov nqi kho mob ntawm cov pob zeb ua vaj tse nyob thoob plaws lub neej ua haujlwm ntawm 30 - 40 xyoo. Lwm yam tshwj xeeb admixtures muaj xws li shrinkage-txo admixtures thiab alkali-silica reactivity inhibitors. Corrosion-inhibiting admixtures muaj kev cuam tshuam me ntsis rau lub zog tom qab hnub nyoog tab sis tuaj yeem ua kom muaj zog thaum ntxov. Calcium nitrite raws li corrosion inhibitors ua kom lub sijhawm teem sijhawm ntawm cov pob zeb hla ntau qhov kev kho kub tshwj tsis yog tias lawv tau tsim nrog cov txheej txheem retarder los cuam tshuam cov nyhuv nrawm.
Post lub sij hawm: Dec-27-2022
