Kuyika nthawi ya konkire ndi chizindikiro chofunikira chomwe chimakhudza khalidwe la zomangamanga ndi kupita patsogolo. Ngati nthawi yoyikirayo ndi yayitali kwambiri, zitha kupangitsa kuti ntchito yomanga ichepe ndikuwononga kuuma kwa konkriti; ngati nthawi yoikika ili yochepa kwambiri, ikhoza kubweretsa zovuta pakupanga konkriti ndikusokoneza ntchito yomanga. Pofuna kukonza nthawi yoyika konkriti, kugwiritsa ntchito zosakaniza zakhala njira yodziwika bwino pakupanga konkire yamakono.Hydroxyethyl Methyl Cellulose (HEMC), monga wamba kusinthidwa cellulose yochokera, chimagwiritsidwa ntchito konkire admixtures ndipo zingakhudze rheology, kusunga madzi, kuika nthawi ndi zina katundu konkire.1. Zinthu zoyambira za HEMC
HEMC ndi cellulose yosinthidwa, yomwe nthawi zambiri imapangidwa kuchokera ku cellulose yachilengedwe kudzera mu ethylation ndi methylation reaction. Ili ndi kusungunuka kwamadzi kwabwino, kukhuthala, kusunga madzi ndi gelling katundu, choncho amagwiritsidwa ntchito kwambiri pomanga, zokutira, mankhwala tsiku ndi tsiku ndi zina. Mu konkire, HEMC nthawi zambiri imagwiritsidwa ntchito ngati thickener, madzi osungira madzi ndi rheology control agent, yomwe imatha kupititsa patsogolo ntchito ya konkire, kuonjezera kumamatira ndikutalikitsa nthawi yokhazikitsa.
2. Zotsatira za HEMC pakuyika nthawi ya konkire
Kuchedwetsa nthawi yokhazikitsa
Monga chotengera cha cellulose, HEMC ili ndi magulu ambiri a hydrophilic mu kapangidwe kake ka maselo, omwe amatha kuyanjana ndi mamolekyu amadzi kuti apange ma hydrate okhazikika, motero amachedwetsa njira ya simenti ya hydration mpaka pamlingo wina. Ma hydration reaction ya simenti ndiyo njira yayikulu yolimbikitsira konkriti, ndipo kuwonjezera kwa HEMC kungakhudze nthawi yokhazikika kudzera m'njira zotsatirazi:
Kusungidwa kwamadzi kowonjezereka: HEMC imatha kusintha kwambiri kusungirako madzi konkire, kuchepetsa kuthamanga kwa madzi, ndikutalikitsa nthawi ya simenti hydration reaction. Kupyolera mu kusungirako madzi, HEMC ikhoza kupeŵa kutaya madzi ochulukirapo, potero kuchedwetsa kuchitika koyambirira ndi komaliza.
Kuchepetsa kutentha kwa hydration: HEMC ingalepheretse kugundana ndi hydration zomwe tinthu tating'ono ta simenti mwa kuwonjezera kukhuthala kwa konkire ndikuchepetsa kuthamanga kwa tinthu tating'ono ta simenti. Kutsika kwa hydration kumathandizira kuchepetsa nthawi yoyika konkriti.
Kusintha kwa Rheological: HEMC imatha kusintha mawonekedwe a konkire, kukulitsa kukhuthala kwake, ndikusunga phala la konkire kuti likhale labwino koyambirira, kupewa zovuta zomanga zomwe zimayambitsidwa ndi kukomoka kwambiri.
Zinthu zosonkhezera
Zotsatira zaMtengo HEMCpakukhazikitsa nthawi sizongogwirizana kwambiri ndi mlingo wake, komanso zimakhudzidwa ndi zinthu zina zakunja:
Kulemera kwa molekyulu ndi digiri ya kusintha kwa HEMC: Kulemera kwa molekyulu ndi digiri ya kusintha (degree of substitution of ethyl ndi methyl) ya HEMC imakhudza kwambiri ntchito yake. HEMC yokhala ndi mamolekyu apamwamba kwambiri komanso kuchuluka kwa m'malo mwake nthawi zambiri imatha kupanga maukonde amphamvu kwambiri, kuwonetsa kusungika bwino kwa madzi ndi kukhuthala, kotero kuti kuchedwa pakukhazikitsa nthawi kumakhala kofunika kwambiri.
Mtundu wa simenti: Mitundu yosiyanasiyana ya simenti ili ndi mitundu yosiyanasiyana ya hydration, kotero zotsatira za HEMC pazitsulo zosiyanasiyana za simenti ndizosiyana. Simenti wamba ya Portland imakhala ndi madzi othamanga kwambiri, pamene simenti ina yotentha kwambiri kapena simenti yapadera imakhala ndi mlingo wochepa wa hydration, ndipo udindo wa HEMC mu machitidwewa ukhoza kukhala wotchuka kwambiri.
Environmental zinthu: chilengedwe zinthu monga kutentha ndi chinyezi ndi chikoka pa atakhala nthawi konkire. Kutentha kwapamwamba kudzafulumizitsa hydration reaction ya simenti, zomwe zimapangitsa kuti pakhale nthawi yofupikitsa, ndipo zotsatira za HEMC m'madera otentha zimatha kufooka. M'malo mwake, m'malo otsika kutentha, kuchedwa kwa HEMC kungakhale koonekeratu.
Kukhazikika kwa HEMC: Kuchuluka kwa HEMC kumatsimikizira mwachindunji kuchuluka kwa mphamvu zake pa konkire. Kuchuluka kwa HEMC kungapangitse kwambiri kusungirako madzi ndi rheology ya konkire, potero kuchedwetsa bwino nthawi yoikika, koma HEMC yochuluka ingayambitse kusayenda bwino kwa konkire ndikukhudza ntchito yomanga.
Synergistic zotsatira za HEMC ndi zosakaniza zina
HEMC nthawi zambiri imagwiritsidwa ntchito ndi zosakaniza zina (monga zochepetsera madzi, zochepetsera, etc.) kuti zisinthe bwino momwe konkriti imagwirira ntchito. Ndi mgwirizano wa ochedwetsa, kuchedwa kwa HEMC kungapitirire patsogolo. Mwachitsanzo, synergistic zotsatira za ena retarders monga phosphates ndi shuga admixtures ndi HEMC akhoza kwambiri kuwonjezera nthawi yoika konkire, amene ali oyenera ntchito yapadera nyengo yotentha kapena kumafuna nthawi yaitali yomanga.
3. Zotsatira zina za HEMC pazinthu za konkire
Kuwonjezera pa kuchedwetsa nthawi yoikika, HEMC imakhalanso ndi zotsatira zofunikira pazinthu zina za konkire. Mwachitsanzo, HEMC ikhoza kupititsa patsogolo madzi, kusagwirizana, kupopera ntchito komanso kukhazikika kwa konkire. Pamene mukukonzekera nthawi yoikika, kukhuthala ndi kusungirako madzi kwa HEMC kungathenso kuteteza bwino kulekanitsa kapena kukhetsa magazi kwa konkire, ndikuwongolera khalidwe lonse ndi kukhazikika kwa konkire.
Hydroxyethyl methylcellulose (HEMC) imatha kuchedwetsa nthawi yoyika konkire kudzera mu kusungirako bwino kwa madzi, kukhuthala ndi zotsatira zake zamakhalidwe. Kuchuluka kwa chikoka cha HEMC kumakhudzidwa ndi zinthu monga kulemera kwake kwa maselo, kuchuluka kwa kusintha, mtundu wa simenti, kuphatikiza kosakanikirana ndi chilengedwe. Poyang'anira moyenera mlingo ndi gawo la HEMC, nthawi yoikika ikhoza kukulitsidwa bwino ndikuwonetsetsa kuti ntchito yomanga konkriti, komanso kukhazikika kwa konkire kungapitirire. Komabe, kugwiritsa ntchito mopitirira muyeso kwa HEMC kungabweretsenso zotsatira zoipa, monga kuchepa kwa madzi kapena kusakwanira kwa hydration, kotero ziyenera kugwiritsidwa ntchito mosamala malinga ndi zosowa zenizeni zaumisiri.
Nthawi yotumiza: Nov-21-2024