Hnub Kawg:11, Sept,2023

Txij li thaum xyoo 1980s, cov khoom siv sib xyaw ua ke, feem ntau cov dej ua kom muaj txiaj ntsig zoo txo ​​cov neeg ua haujlwm, tau maj mam txhawb nqa thiab siv hauv kev lag luam hauv tsev, tshwj xeeb tshaj yog cov pob zeb muaj zog thiab cov twj tso kua mis, thiab tau dhau los ua cov khoom tseem ceeb. Raws li Malhotra tau taw qhia ntawm thawj lub rooj sib tham thoob ntiaj teb ntawm Cov Khoom Siv Khoom Siv: "Kev txhim kho thiab kev siv cov dej txo cov neeg ua haujlwm tau zoo yog qhov tseem ceeb hauv kev nce qib ntawm kev siv tshuab ua vaj tse nyob rau hauv lub xyoo pua 20th." Tsuas muaj ob peb qhov tseem ceeb ntawm kev ua vaj tse nyob rau xyoo tas los no, ib qho yog kev txhim kho ntawm cov cua nkag hauv xyoo 1940, uas tau hloov lub ntsej muag ntawm cov cuab yeej ua vaj tse hauv North America;Superplasticizeryog lwm qhov kev ua txhaum loj uas yuav muaj kev cuam tshuam loj rau kev tsim khoom thiab kev siv cov pob zeb rau ntau xyoo tom ntej.

Superplasticizernyob rau qee lub tebchaws hu uasuperplasticizer, raws li lub npe qhia, nws yog heev haum rau kev npaj ntawm superplasticized qhob mix. Ntawm chav kawm, nws yog qhov tsim nyog tshaj plaws rau kev sib tov sib xyaw nrog cov dej ntws loj, qhov loj slurry ntim thiab qis dej-binder piv, uas yog, siv cov pob zeb muaj zog.

Txawm li cas los xij, rau qee qhov kev ua vaj tse, xws li cov pob zeb uas tau nchuav rau hauv lub pas dej hydraulic, qhov siab tshaj plaws ntawm cov khoom sib xyaw yog loj (txog 150mm), slurry ntim me me thiab ntws tsis loj, thiab cov pob zeb yuav tsum tau compacted. los ntawm kev siv lub zog vibration los yog kev vibration dov, qhov ua haujlwm siab dej reducer yuav tsis haum. Txhawm rau kom cov dej-binder piv tsis hloov pauv, txhawm rau ua kom tau raws li cov cuab yeej cuab yeej cuab tam uas yuav tsum tau ua los ntawm cov qauv tsim, txo cov dej siv, thiab txo cov khoom siv cementing raws li lub tswv yim, ntau qhov kev tsim kho hauv tsev hydraulic kuj tseem sib xyaw nrog kev ua haujlwm siab. dej reducer. Qhov tseeb, xws li daim ntawv thov no muaj teeb meem, vim hais tias ua ntej hydraulic pob zeb yog tov nrog huab cua entraining tus neeg saib xyuas los yog lignin hom zoo tib yam dej reducer, lawv cov dej txo tus nqi me me, thiab vim cov nyhuv ntawm huab cua entraining, nce lub ntim ntawm slurry, yog li ntawd. Thaum cov dej siv thiab cov khoom siv cementing raug txo nyob rau tib lub sijhawm, uas yog, thaum lub ntim ntawm slurry raug txo, nws tuaj yeem tswj tau qhov sib npaug ntxhib. Xyuas kom meej tias muaj qhov chaw txaus los sau cov aggregate, qhwv cov aggregate thiab muab cov slurry ua haujlwm yog qhov tsim nyog rau kev sib xyaw kom haum tom qab nchuav.

Tsis tas li ntawd, lub zog compressive ntawm kev sib xyaw nrog cov dej ua haujlwm siab txo tus neeg saib xyuas kom txo cov dej sib txuas tuaj yeem txhim kho tau zoo tom qab hardening, tab sis qhov khoov lub zog loj hlob feem ntau yog me me, thiab kev tawg rhiab heev yuav nce, yog li feem ntau, kev tsim kho ntawm pob zeb pavement lossis choj vaj huam sib luag yuav tsum tau ceev faj nrog kev ua haujlwm siab dej txo tus neeg sawv cev. Qhov tseeb, nyob rau hauv kev npaj ntawm ntau tshaj plaws ntawm C30 nyob rau hauv pej xeem kev tsim kho thiab civil engineering (yuav tsum account rau ntau tshaj 1/2 ntawm tag nrho cov) los yog ib co qis zog qib ntawm pumped pob zeb, high efficiency dej reducer yog tsis tsim nyog, los yog tsis yog ib feem tseem ceeb.