Ua rau poob poob

1. Kev cuam tshuam ntawm cov khoom siv raw

Txawm hais tias cov cement thiab cov twj tso kua mis siv yog sib txuam thiab yoog raws, yuav tsum tau muab los ntawm kev ntsuas kev hloov pauv, cov twj tso kua mis sib xyaw los txiav txim siab qhov sib xyaw kom zoo los ntawm kev ntsuas kev hloov pauv nrog cov khoom siv cementitious. Pumping tus neeg sawv cev hauv huab cua-entraining, retarding tus naj npawb ntawm cov khoom xyaw, slump poob ntawm pob zeb muaj kev cuam tshuam ntau dua, huab cua-entraining, retarding ntau cov khoom xyaw, slump poob ntawm pob zeb yog qeeb, txwv tsis pub poob sai. Naphthalene siab npaum dej txo tus neeg sawv cev formulated qhob slump poob yog ceev, nyob rau hauv qhov tsis zoo kub +5 degree hauv qab no, qhov poob yog qeeb qeeb.

Yog tias tus neeg sawv cev sib xyaw hauv cov cement yog tawv gypsum, nws yuav ua rau poob qis ntawm cov pob zeb kom nrawm, thiab cov ntsiab lus ntawm C3A hauv cov cement yog ntau dua li cov khoom siv thaum ntxov, kev siv "R" hom cement, qhov zoo ntawm cov cement. yog qhov zoo heev, thiab lub sijhawm teem sijhawm ntawm cov cement yog ceev ceev, thiab lwm yam. Tag nrho cov no yuav ua rau lub slump poob ntawm cov pob zeb kom nrawm, thiab qhov poob ntawm cov pob zeb yuav cuam tshuam rau qhov zoo ntawm cov khoom sib xyaw thiab cov khoom sib xyaw hauv cement. Kev poob qis ntawm cov pob zeb muaj feem cuam tshuam rau qhov zoo ntawm cov khoom sib xyaw hauv cov cement thiab qhov sib xyaw. Cov ntsiab lus ntawm C3A hauv cov cement yuav tsum tsis pub dhau 4% mus rau 6%, thaum cov ntsiab lus qis dua 4%, cov khoom siv cua nkag thiab rov qab yuav tsum raug txo, txwv tsis pub nws yuav ua rau cov pob zeb tsis khov rau lub sijhawm ntev, thiab Thaum cov ntsiab lus ntawm C3A siab dua 7%, cov khoom siv cua nkag thiab rov qab yuav tsum tau nce ntxiv, txwv tsis pub nws yuav ua rau cov pob zeb poob sai sai lossis qhov tshwm sim ntawm qhov tsis tseeb coagulation.

Cov ntsiab lus ntawm cov av nkos thiab cov av nkos ntawm cov ntxhib thiab nplua aggregates siv hauv cov pob zeb ntau tshaj li tus qauv, thiab cov ntsiab lus ntawm crushed pob zeb koob zoo li hais tshaj tus qauv, thiab lwm yam yuav ua rau lub slump poob ntawm pob zeb kom nrawm. Yog hais tias lub ntxhib aggregate dej nqus tus nqi yog loj, tshwj xeeb tshaj yog cov crushed pob zeb, nyob rau hauv lub caij ntuj sov kub lub caij tom qab kub kub raug, ib zaug muab tso rau hauv lub tov khoom nws yuav muaj ib tug loj npaum li cas ntawm cov dej nyob rau hauv ib tug luv luv lub sij hawm ntawm lub sij hawm, ua rau ib tug luv luv lub sij hawm. lub sij hawm ntawm lub sij hawm (30min) slump poob ntawm pob zeb ceev ceev.

2. Kev sib xyaw ua haujlwm cuam tshuam

Cov txheej txheem kev sib xyaw ua ke kuj tseem muaj feem cuam tshuam rau kev poob ntawm cov pob zeb tawg, cov qauv sib xyaw thiab kev sib xyaw ua haujlwm muaj feem cuam tshuam, yog li ntawd, cov kev xav tau ntawm cov khoom sib tov yuav tsum tsis tu ncua, cov hniav sib tov yuav tsum tau hloov tsis tu ncua. Lub sijhawm sib xyaw ua ke tsis tuaj yeem tsawg dua 30s, xws li tsawg dua 30s pob zeb poob qis, ua rau poob qis dua.