Katundu wa Simenti Paste Kusinthidwa ndi Cellulose Ether

Ndi kuyeza katundu makina, mlingo madzi posungira, kuika nthawi ndi kutentha hydration wa mapadi efa ndi viscosities osiyana mu Mlingo osiyana simenti phala, ndi ntchito SEM kusanthula mankhwala hydration, zotsatira za mapadi efa pa ntchito ya simenti phala anali. anaphunzira. lamulo lachikoka. Zotsatira zikuwonetsa kuti kuwonjezera kwa cellulose ether kumatha kuchedwetsa simenti, kuchedwetsa kulimba kwa simenti ndikuyika, kuchepetsa kutentha kwa hydration, kutalikitsa nthawi yowoneka bwino ya kutentha kwa hydration, ndipo kuchedwetsa kumawonjezeka ndi kuchuluka kwa mlingo ndi kukhuthala. Ma cellulose ether amatha kuonjezera kuchuluka kwa madzi osungiramo matope, ndipo amatha kupititsa patsogolo kusungirako madzi amatope ndi mawonekedwe ozungulira, koma pamene zomwe zili pamwamba pa 0,6%, kuwonjezeka kwa kusungirako madzi sikuli kofunikira; zili ndi mamasukidwe akayendedwe ndi zinthu zimene zimatsimikizira mapadi kusinthidwa simenti slurry. Pogwiritsira ntchito matope osinthidwa a cellulose ether, mlingo ndi kukhuthala kwake ziyenera kuganiziridwa makamaka.

Mawu ofunikira:cellulose ether; mlingo; kuchedwa; kusunga madzi

Mtondo womangira ndi chimodzi mwazinthu zofunika pakumangira ntchito yomanga. M'zaka zaposachedwa, ndikugwiritsa ntchito kwakukulu kwa zida zotchinjiriza pakhoma ndikuwongolera zofunikira zotsutsana ndi ming'alu ndi anti-seepage pamakoma akunja, zofunikira zapamwamba zayikidwa patsogolo pakukaniza ming'alu, magwiridwe antchito komanso ntchito yomanga matope. Chifukwa cha zofooka za kuchepa kwakukulu kowuma, kusawotchera bwino, ndi mphamvu zochepa zomangira zomangira, matope achikhalidwe nthawi zambiri sangathe kukwaniritsa zofunikira zomanga, kapena kuyambitsa mavuto monga kugwa kwa zipangizo zokongoletsera. Monga matope opaka pulasitala, chifukwa matope amataya madzi mofulumira kwambiri, nthawi yoyika ndi kuumitsa imafupikitsidwa, ndipo mavuto monga kung'amba ndi kutseka kumachitika panthawi yomanga yaikulu, yomwe imakhudza kwambiri khalidwe la polojekitiyi. Mtondo wachikhalidwe umataya madzi mwachangu kwambiri ndipo simenti ya simenti imakhala yosakwanira, zomwe zimapangitsa kuti pakhale nthawi yochepa yotsegulira matope a simenti, omwe ndi chinsinsi chokhudza momwe matopewo amagwirira ntchito.

Ma cellulose ether ali ndi kukhuthala kwabwino komanso kusunga madzi, ndipo akhala akugwiritsidwa ntchito kwambiri m'munda wamatope, ndipo wakhala wosakanizidwa wofunikira kwambiri kuti apititse patsogolo kasungidwe kamadzi amatope ndikupereka ntchito yomanga, kuchepetsa ntchito yomanga ndikugwiritsanso ntchito matope achikhalidwe. . Vuto la kutaya madzi mkatikati. Ma cellulose omwe amagwiritsidwa ntchito mumatope nthawi zambiri amaphatikizapo methyl cellulose ether (MC), hydroxypropyl methyl cellulose (HPMC), hydroxyethyl methyl cellulose ether (HEMC), hydroxyethyl cellulose ether (HEC), etc. Pakati pawo, HPMC ndi HEMC ndizogwiritsidwa ntchito kwambiri.

Pepalali makamaka limaphunzira momwe ma cellulose ether amagwirira ntchito (kuchuluka kwa madzi, kutayika kwa madzi ndi nthawi yoyika), zida zamakina (mphamvu zopondereza komanso mphamvu zama bond), malamulo a hydration ndi microstructure ya phala la simenti. Amapereka chithandizo cha katundu wa cellulose ether kusinthidwa simenti phala ndipo amapereka umboni kwa ntchito mapadi etere kusinthidwa matope.

1. Yesani

1.1 Zopangira

Simenti: Simenti wamba ku Portland (PO 42.5) simenti yopangidwa ndi Wuhan Yadong Cement Company, yokhala ndi malo enieni a 3500 cm.²/g.

Ma cellulose ether: hydroxypropyl methylcellulose ether (MC-5, MC-10, MC-20, viscosities of 50,000 Pa)·S, 100000 Pa·S, 200000 Pa·S, motero).

1.2 Njira

Makina katundu: Pokonzekera chitsanzo, mlingo wa cellulose ether ndi 0.0% ~ 1.0% ya simenti misa, ndi madzi-simenti chiŵerengero ndi 0,4. Musanathire madzi ndi kusonkhezera, sakanizani cellulose ether ndi simenti mofanana. Phala la simenti lokhala ndi chitsanzo cha 40 x 40 x 40 linagwiritsidwa ntchito poyesa.

Kukhazikitsa nthawi: Njira yoyezera ikuchitika molingana ndi GB/T 1346-2001 "Cement Standard Consistency Water Consumption, Kukhazikitsa Nthawi, Njira Yoyesera Yokhazikika".

Kusungirako madzi: Kuyesa kwa kusungirako madzi kwa phala la simenti kumatengera muyezo wa DIN 18555 "Njira yoyesera ya matope a inorganic cementitious material".

Kutentha kwa hydration: Kuyesaku kutengera TAM Air microcalorimeter ya TA Instrument Company ya United States, ndipo chiŵerengero cha simenti yamadzi ndi 0.5.

Hydration mankhwala: Sakanizani madzi ndi mapadi etha mofanana, ndiye konzani slurry simenti, kuyamba nthawi, kutenga zitsanzo pa nthawi zosiyanasiyana, kusiya hydration ndi Mowa mtheradi kuyezetsa, ndi madzi simenti chiŵerengero ndi 0,5.

2. Zotsatira ndi zokambirana

2.1 Makina katundu

Kuchokera ku chikoka cha cellulose ether zomwe zili pa mphamvu, zikhoza kuwoneka kuti ndi kuwonjezeka kwa MC-10 cellulose ether content, mphamvu za 3d, 7d ndi 28d zonse zimachepa; cellulose ether amachepetsa mphamvu ya 28d kwambiri. Kuchokera ku chikoka cha cellulose ether viscosity pa mphamvu, zitha kuwoneka kuti ngati ndi cellulose ether yokhala ndi mamasukidwe a 50,000 kapena 100,000 kapena 200,000, mphamvu ya 3d, 7d, ndi 28d idzachepa. Zitha kuwonedwanso kuti cellulose ether Viscosity ilibe mphamvu yayikulu pamphamvu.

2.2 Kukhazikitsa nthawi

Kuchokera ku zotsatira za zomwe zili 100,000 viscosity cellulose ether pa nthawi yokhazikitsa, zikhoza kuwoneka kuti ndi kuwonjezeka kwa zomwe zili mu MC-10, nthawi yoyamba yokonzekera komanso nthawi yomaliza yowonjezera. Pamene zomwe zili 1%, nthawi yoyamba yoyika Idafika 510min, ndipo nthawi yomaliza yokonzekera inafika 850min. Poyerekeza ndi zomwe zilibe kanthu, nthawi yoyamba yokhazikitsa idatalikitsidwa ndi 210min, ndipo nthawi yomaliza yomaliza idatalikitsidwa ndi 470min.

Kuchokera ku chikoka cha cellulose ether viscosity pakukhazikitsa nthawi, zitha kuwoneka kuti ndi MC-5, MC-10 kapena MC-20, zitha kuchedwetsa kuyika kwa simenti, koma poyerekeza ndi ma cellulose ethers atatu, koyambira koyamba. nthawi ndi kukhazikitsidwa komaliza Nthawiyo imatalika ndi kuwonjezeka kwa mamasukidwe akayendedwe. Ichi ndi chifukwa mapadi ether akhoza adsorbed pamwamba pa simenti particles, potero kuteteza madzi kukhudzana ndi particles simenti, potero kuchedwa simenti hydration. Kuchuluka kwa mamasukidwe a cellulose ether, kumapangitsanso kukhuthala kwa ma adsorption pamwamba pa tinthu tating'ono ta simenti, ndipo kumachepetsanso kwambiri.

2.3 Mlingo wosunga madzi

Kuchokera ku chikoka cha malamulo a cellulose ether okhutira pa mlingo wosungira madzi, zikhoza kuwoneka kuti ndi kuwonjezeka kwa zomwe zili, kuchuluka kwa madzi osungiramo matope kumawonjezeka, ndipo pamene ma cellulose ether ali oposa 0,6%, mlingo wosungira madzi ndi khola m'chigawo. Komabe, poyerekeza ma ethers atatu a cellulose, pali kusiyana pakati pa kukhudzidwa kwa mamasukidwe akayendedwe pamlingo wosunga madzi. Pansi pa mlingo womwewo, ubale pakati pa kuchuluka kwa kusunga madzi ndi: MC-5≤MC-10≤MC-20.

2.4 Kutentha kwa hydration

Kuchokera ku zotsatira za mtundu wa cellulose etere ndi zomwe zili pa kutentha kwa hydration, zikhoza kuwonedwa kuti ndi kuwonjezeka kwa MC-10, kutentha kwa hydration kumachepa pang'onopang'ono, ndipo nthawi ya kutentha kwa hydration imasintha pambuyo pake; Kutentha kwa hydration kunalinso ndi chikoka chachikulu. Ndi kuwonjezeka kwa mamasukidwe akayendedwe, kutentha kwa hydration kunachepa kwambiri, ndipo nsonga ya kutentha kwa hydration inasintha kwambiri pambuyo pake. Zimasonyeza kuti cellulose ether akhoza kuchedwetsa simenti hydration, ndipo zotsatira zake retarding zimagwirizana ndi zili ndi mamasukidwe akayendedwe a cellulose ether, amene n'zogwirizana ndi kusanthula zotsatira kuika nthawi.

2.5 Kusanthula kwazinthu zamagetsi

Kuchokera pakuwunika kwa SEM kwa mankhwala a 1d hydration, zitha kuwoneka kuti 0.2% MC-10 cellulose ether ikuwonjezeredwa, kuchuluka kwa clinker yopanda madzi ndi ettringite yokhala ndi crystallization yabwino imatha kuwoneka. %, makhiristo a ettringite amachepetsedwa kwambiri, zomwe zikuwonetsa kuti cellulose ether imatha kuchedwetsa hydration ya simenti komanso kupanga zinthu za hydration nthawi yomweyo. Poyerekeza mitundu itatu ya ma cellulose ethers, zitha kupezeka kuti MC-5 imatha kupanga crystallization ya ettringite muzinthu zamadzimadzi nthawi zonse, ndipo crystallization ya ettringite imakhala yokhazikika. zogwirizana ndi makulidwe a wosanjikiza.

3. Mapeto

a. Kuphatikizika kwa cellulose ether kudzachedwetsa hydration ya simenti, kuchedwetsa kuumitsa ndi kukhazikitsa simenti, kuchepetsa kutentha kwa hydration, ndikutalikitsa nthawi yowoneka bwino ya kutentha kwa hydration. Ndi kuchuluka kwa mlingo ndi mamasukidwe akayendedwe, retarping zotsatira adzawonjezeka.

b. Cellulose ether imatha kuonjezera kuchuluka kwa madzi osungiramo matope, ndipo imatha kupititsa patsogolo kusungidwa kwamadzi mumatope ndi mawonekedwe opyapyala. Kusungidwa kwa madzi ake kumagwirizana ndi mlingo ndi kukhuthala kwake. Pamene mlingo umaposa 0.6%, zotsatira zosungira madzi sizikuwonjezeka kwambiri.