Methyl cellulose ether pa kutentha kwa chipinda kuchiritsa konkire yogwira ntchito kwambiri

Chidule: Mwa kusintha zomwe zili mu hydroxypropyl methylcellulose ether (HPMC) mu kutentha kwabwino kuchiritsa konkire yapamwamba kwambiri (UHPC), zotsatira za cellulose ether pa fluidity, kuika nthawi, mphamvu yopondereza, ndi mphamvu yosinthika ya UHPC inaphunziridwa. , mphamvu ya axial tensile ndi mtengo wotsiriza wokhazikika, ndipo zotsatira zake zinasanthulidwa. Zotsatira zoyesa zikuwonetsa kuti: kuwonjezera zosaposa 1.00% ya HPMC yotsika kwambiri sikumakhudza fluidity ya UHPC, koma kumachepetsa kutayika kwa madzi pakapita nthawi. , ndi kutalikitsa nthawi yokhazikitsa, kuwongolera kwambiri ntchito yomanga; pamene zomwe zili pansi pa 0.50%, zotsatira za mphamvu zopondereza, mphamvu zowonongeka ndi axial tensile mphamvu sizofunika, ndipo kamodzi zomwe zili pamwamba pa 0.50%, makina ake Kuchita kumachepetsedwa ndi 1/3. Poganizira machitidwe osiyanasiyana, mlingo woyenera wa HPMC ndi 0.50%.

Mawu ofunikira: konkire yogwira ntchito kwambiri; cellulose ether; kutentha kwabwinobwino kuchiritsa; compressive mphamvu; flexural mphamvu; kulimba kwamakokedwe

0,Mawu Oyamba

Ndikukula kwachangu kwamakampani omanga ku China, zofunikira pakugwirira ntchito konkriti muumisiri weniweni zawonjezekanso, ndipo konkriti yapamwamba kwambiri (UHPC) yapangidwa potsatira zomwe akufuna. Gawo labwino kwambiri la tinthu tating'onoting'ono tosiyanasiyana tating'onoting'ono tating'onoting'ono tapangidwa, ndipo timasakanizidwa ndi chitsulo chachitsulo komanso chochepetsera madzi, chimakhala ndi zinthu zabwino kwambiri monga kulimba kwambiri, kulimba kwambiri, kulimba kwamphamvu kwambiri komanso kudzichiritsa mwamphamvu. luso la microcracks. Kachitidwe. Kafukufuku waukadaulo wakunja pa UHPC ndi wokhwima ndipo wagwiritsidwa ntchito pama projekiti ambiri othandiza. Poyerekeza ndi mayiko akunja, kafukufuku wapakhomo sali wozama mokwanira. Dong Jianmiao ndi ena adaphunzira kuphatikizika kwa ulusi powonjezera mitundu yosiyanasiyana ndi kuchuluka kwa ulusi. Chikoka limagwirira ndi lamulo la konkire; Chen Jing et al. anaphunzira mphamvu ya zitsulo zachitsulo m'mimba mwake pa ntchito ya UHPC posankha ulusi wachitsulo wokhala ndi ma diameter 4. UHPC ili ndi mapulogalamu ochepa chabe a uinjiniya ku China, ndipo ikadali pagawo la kafukufuku wazongopeka. Kuchita kwa UHPC Superiority kwakhala imodzi mwa njira zofufuzira za chitukuko cha konkriti, komabe pali mavuto ambiri omwe akuyenera kuthetsedwa. Monga zofunikira zazikulu za zipangizo, kukwera mtengo, njira zovuta kukonzekera, ndi zina zotero, zolepheretsa chitukuko cha teknoloji yopanga UHPC. Pakati pawo, kugwiritsa ntchito mpweya wothamanga kwambiri Kuchiritsa kwa UHPC pa kutentha kwakukulu kungapangitse kuti ipeze mphamvu zamakina apamwamba komanso kulimba. Komabe, chifukwa chazovuta zamachiritso a nthunzi komanso zofunika kwambiri pazida zopangira, kugwiritsa ntchito zida kumatha kungokhala mayadi opangiratu, ndipo kumangidwa kwapamalo sikungachitike. Choncho, sikoyenera kutengera njira yochiritsira matenthedwe mu ntchito zenizeni, ndipo m'pofunika kuchita kafukufuku wozama pa kutentha kwabwino kuchiritsa UHPC.

Kutentha kwanthawi zonse kuchiritsa UHPC kuli pochita kafukufuku ku China, ndipo chiŵerengero chake cha madzi-to-binder ndi chochepa kwambiri, ndipo chimakonda kutaya madzi m'thupi mofulumira pamtunda pomanga malo. Pofuna kukonza bwino vuto la kuchepa kwa madzi m'thupi, zida zopangira simenti nthawi zambiri zimawonjezera zowonjezera zosungira madzi kuzinthuzo. Mankhwalawa amateteza kugawanika ndi kutulutsa magazi kwazinthu, kupititsa patsogolo kusungirako madzi ndi mgwirizano, kupititsa patsogolo ntchito yomanga, komanso kukonza bwino makina azinthu zopangidwa ndi simenti. Hydroxypropyl methyl cellulose ether (HPMC) ngati polima Thickener, yomwe imatha kugawira bwino polima gelled slurry ndi zinthu muzinthu zokhala ndi simenti mofanana, komanso madzi aulere mu slurry adzakhala madzi omangika, kotero kuti sizovuta kutaya kuchokera. slurry ndi kupititsa patsogolo ntchito yosungira madzi konkire .Kuti muchepetse mphamvu ya cellulose ether pa fluidity ya UHPC, low-viscosity cellulose ether anasankhidwa kuti ayesedwe.

Mwachidule, pofuna kupititsa patsogolo ntchito yomanga pamaziko owonetsetsa kuti makina a UHPC akuchiritsa kutentha kwanthawi zonse, pepala ili limafotokoza zotsatira za low-viscosity cellulose ether zomwe zili pakuchiritsa kutentha kwanthawi zonse kutengera mankhwala a cellulose ether. ndi njira yake yochitira mu UHPC slurry. Chikoka cha fluidity, nthawi coagulation, compressive mphamvu, flexural mphamvu, axial kosunthika mphamvu ndi mtheradi kolimba mtengo wa UHPC kudziwa mlingo woyenera wa cellulose ether.

1. Ndondomeko yoyesera

1.1 Yesani zida zopangira ndikusakaniza

Zida zopangira mayesowa ndi:

1) Simenti: P·O 52.5 wamba Portland simenti opangidwa ku Liuzhou.

2) Phulusa louluka: Phulusa lopangidwa ku Liuzhou.

3) Slag ufa: S95 granulated kuphulika ng'anjo slag ufa wopangidwa ku Liuzhou.

4) silika fume: theka-encrypted silika fume, imvi ufa, SiO2 zili≥92%, malo enieni a 23 m²/g.

5) Mchenga wa quartz: 20 ~ 40 mauna (0.833 ~ 0.350 mm).

6) Chotsitsa madzi: chotsitsa madzi cha polycarboxylate, ufa woyera, kuchuluka kwa madzi≥30%.

7) Latex ufa: redispersible latex ufa.

8) Fiber ether: hydroxypropyl methylcellulose METHOCEL yopangidwa ku United States, viscosity 400 MPa s.

9) Chitsulo CHIKWANGWANI: owongoka mkuwa-yokutidwa microwire zitsulo CHIKWANGWANI, awiriφ ndi 0.22 mm, kutalika ndi 13 mm, mphamvu yamanjenje ndi 2 000 MPa.

Pambuyo pa kafukufuku wambiri woyesera koyambirira, zitha kutsimikiziridwa kuti kusakaniza koyambira kutentha koyenera kuchiritsa konkire wopitilira muyeso ndi simenti: phulusa la ntchentche: ufa wamchere: fume la silika: mchenga: wochepetsera madzi: ufa wa latex: madzi = 860: 42: 83: 110:980:11:2:210, kuchuluka kwa zitsulo zachitsulo ndi 2%. Onjezani 0, 0.25%, 0.50%, 0.75%, 1.00% HPMC ya cellulose ether (HPMC) zomwe zili pazigawo zosakanikirana izi Konzani zoyeserera zofananira motsatana.

1.2 Njira yoyesera

Yezerani ufa wouma zopangira molingana ndi kusakaniza ndi kuziyika mu HJW-60 single-horizontal shaft yokakamiza konkire chosakanizira. Yambani chosakanizira mpaka yunifolomu, onjezerani madzi ndikusakaniza kwa mphindi zitatu, zimitsani chosakaniza, onjezerani zitsulo zolemera zachitsulo ndikuyambitsanso chosakanizira kwa mphindi ziwiri. Zapangidwa kukhala UHPC slurry.

Zinthu zoyeserera zimaphatikizapo madzimadzi, nthawi yoyikira, mphamvu yopondereza, mphamvu yosinthika, mphamvu ya axial tensile komanso mtengo womaliza. Mayeso a fluidity amatsimikiziridwa molingana ndi JC/T986-2018 "Cement-based Grouting Materials". Mayeso a nthawi yoyika ndi molingana ndi GB / T 1346-2011 "Cement Standard Consistency Water Consumption and Setting Time Test Method". Kuyesa kwamphamvu kwamphamvu kumatsimikiziridwa molingana ndi GB/T50081-2002 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete". Mayeso amphamvu oponderezedwa, kulimba kwa axial komanso Kuyesa komaliza kwamtengo wapatali kumatsimikiziridwa molingana ndi DLT5150-2001 "Hydraulic Concrete Test Regulations".

2. Zotsatira za mayeso

2.1 Liquidity

Zotsatira za mayeso a fluidity zikuwonetsa kukhudzidwa kwa zomwe zili mu HPMC pakutayika kwa UHPC fluidity pakapita nthawi. Zimawonedwa kuchokera ku zochitika zoyesa kuti pambuyo pa slurry popanda cellulose ether imagwedezeka mofanana, pamwamba pamakhala kuchepa kwa madzi m'thupi ndi kutumphuka, ndipo fluidity imatayika mwamsanga. , ndipo kusagwira ntchito bwino kumasokonekera. Pambuyo powonjezera ma cellulose ether, panalibe khungu pamtunda, kutaya kwa madzimadzi pakapita nthawi kunali kochepa, ndipo kugwira ntchito kumakhalabe bwino. Mkati mwa mayeso, kuchepa kochepa kwa fluidity kunali 5 mm mu mphindi 60. Kuwunika kwa deta yoyesera kumasonyeza kuti, Kuchuluka kwa ether ya cellulose ether yotsika kwambiri imakhala ndi zotsatira zochepa pa fluidity yoyamba ya UHPC, koma imakhudza kwambiri kutaya kwa madzi pakapita nthawi. Ngati palibe ether ya cellulose yowonjezeredwa, kutaya kwa fluidity kwa UHPC ndi 15 mm; Ndi kuwonjezeka kwa HPMC, kutaya madzimadzi kwa matope kumachepa; pamene mlingo ndi 0,75%, kutaya kwa fluidity kwa UHPC ndi kochepa kwambiri ndi nthawi, yomwe ndi 5mm; pambuyo pake, ndi kuwonjezeka kwa HPMC, kutaya kwa fluidity kwa UHPC ndi nthawi Pafupifupi zosasinthika.

PambuyoMtengo wa HPMCwosakanikirana ndi UHPC, zimakhudza rheological properties za UHPC kuchokera ku mbali ziwiri: imodzi ndi yodziimira yaying'ono-thovu amabweretsedwa mu ndondomeko yogwira ntchito, yomwe imapangitsa kuti aggregate ndi ntchentche phulusa ndi zipangizo zina apange "mpira zotsatira", zomwe zimawonjezera Kugwira ntchito nthawi yomweyo, zinthu zambiri za simenti zimatha kukulunga mophatikizira, kotero kuti chophatikizacho chikhoza "kuyimitsidwa" molingana ndi slurry, ndipo chimatha kusuntha momasuka, kukangana pakati pamagulu kumachepetsedwa, ndipo kuchuluka kwamadzi kumawonjezeka; chachiwiri ndikuwonjezera UHPC Mphamvu yogwirizana imachepetsa madzimadzi. Popeza mayeso amagwiritsa ntchito otsika mamasukidwe akayendedwe HPMC, mbali yoyamba ndi yofanana ndi mbali yachiwiri, ndipo madzimadzi oyambirira sasintha kwambiri, koma kutaya kwa fluidity pakapita nthawi kungachepetse. Malinga ndi kuwunika kwa zotsatira za mayeso, zitha kudziwika kuti kuwonjezera kuchuluka koyenera kwa HPMC ku UHPC kumatha kupititsa patsogolo ntchito yomanga ya UHPC.

2.2 Kukhazikitsa nthawi

Kuchokera pakusintha kwa nthawi yokhazikitsidwa kwa UHPC yokhudzidwa ndi kuchuluka kwa HPMC, zitha kuwoneka kuti HPMC imagwira ntchito yochedwetsa mu UHPC. Kuchuluka kwake kumakhala kokulirapo, m'pamenenso kuchedwetsa kumawonekera. Pamene ndalamazo ndi 0.50%, nthawi yoyika matope ndi 55min. Poyerekeza ndi gulu lolamulira (40 min), linawonjezeka ndi 37.5%, ndipo kuwonjezeka sikunali koonekeratu. Pamene mlingo unali 1.00%, nthawi yoyika matope inali 100 min, yomwe inali 150% kuposa ya gulu lolamulira (40 min).

Mapangidwe a maselo a cellulose ether amakhudzanso kuchedwetsa kwake. Kapangidwe kake ka maselo mu cellulose ether, ndiko kuti, mawonekedwe a mphete ya anhydroglucose, amatha kuchitapo kanthu ndi ayoni a calcium kupanga ma cell a shuga-calcium, kuchepetsa nthawi yopatsa mphamvu ya simenti ya clinker hydration reaction. Ca(OH)2, kuchepetsa liwiro la simenti hydration, potero kuchedwetsa kuyika kwa simenti.

2.3 Mphamvu zopondereza

Kuchokera paubwenzi pakati pa mphamvu zowonongeka za zitsanzo za UHPC pa masiku a 7 ndi masiku a 28 ndi zomwe zili mu HMPC, zikhoza kuwoneka bwino kuti kuwonjezera kwa HPMC pang'onopang'ono kumawonjezera kuchepa kwa mphamvu ya UHPC. 0.25% HPMC, mphamvu yopondereza ya UHPC imachepa pang'ono, ndipo mphamvu yopondereza ndi 96%. Kuwonjezera 0.50% HPMC alibe zotsatira zoonekeratu pa compressive mphamvu chiŵerengero cha UHPC. Pitirizani kuwonjezera HPMC mkati mwazomwe mungagwiritse ntchito, UHPC's Mphamvu yopondereza idachepa kwambiri. Pamene zomwe zili mu HPMC zidawonjezeka kufika ku 1.00%, chiŵerengero cha mphamvu ya compressive chinatsika mpaka 66%, ndipo kutaya mphamvu kunali kwakukulu. Malinga ndi kusanthula deta, ndi koyenera kwambiri kuwonjezera 0.50% HPMC, ndi kutaya mphamvu compressive pang'ono.

HPMC ili ndi mphamvu yolowetsa mpweya. Kuwonjezera kwa HPMC kudzachititsa kuti ma microbubbles angapo mu UHPC achepetse kuchuluka kwa UHPC yosakanikirana. Pambuyo pakuwumitsidwa kwa slurry, porosity idzawonjezeka pang'onopang'ono ndipo compactness idzachepa, makamaka zomwe zili mu HPMC. Zapamwamba. Kuonjezera apo, ndi kuwonjezeka kwa kuchuluka kwa HPMC komwe kunayambitsidwa, palinso ma polima ambiri osinthika mu pores a UHPC, omwe sangakhale ndi gawo lofunikira pakukhazikika kwabwino komanso kuthandizira kuthandizira pamene matrix a composite cementitious atsekedwa. .Chifukwa chake, kuwonjezera kwa HPMC kumachepetsa kwambiri mphamvu yopondereza ya UHPC.

2.4 Mphamvu ya Flexural

Kuchokera paubwenzi pakati pa mphamvu zosinthika za zitsanzo za UHPC pa masiku a 7 ndi masiku a 28 ndi zomwe zili mu HMPC, zikhoza kuwoneka kuti kusintha kwa ma flexural mphamvu ndi mphamvu zopondereza ndizofanana, ndi kusintha kwa mphamvu zosinthika pakati pa 0 ndi 0.50% ya HMPC si yofanana. Pamene kuwonjezera kwa HPMC kunkapitirira, mphamvu zosinthika za zitsanzo za UHPC zinatsika kwambiri.

Zotsatira za HPMC pa mphamvu ya flexural ya UHPC makamaka m'zinthu zitatu: cellulose ether imakhala ndi retarding ndi mpweya-entraining zotsatira, zomwe zimachepetsa mphamvu yosinthika ya UHPC; ndi mbali yachitatu ndi kusinthasintha polima opangidwa ndi mapadi efa, Kuchepetsa kukhazikika kwa chitsanzo kumachepetsa kuchepa kwa flexural mphamvu ya chitsanzo pang'ono. Kukhalapo kwa nthawi imodzi kwa mbali zitatuzi kumachepetsa mphamvu yopondereza ya chitsanzo cha UHPC komanso kumachepetsa mphamvu yosinthasintha.

2.5 Mphamvu yamakomedwe a Axial komanso kufunikira komaliza

Ubale pakati pa kulimba kwamphamvu kwa zitsanzo za UHPC pa 7 d ndi 28 d ndi zomwe zili mu HMPC. Ndi kuchuluka kwa zomwe zili mu HPMC, mphamvu zolimba za zitsanzo za UHPC zidasintha pang'ono kenako zidatsika mwachangu. Kupindika kwamphamvu kwamphamvu kukuwonetsa kuti zomwe zili mu HPMC pachitsanzozi zikafika pa 0.50%, mphamvu ya axial tensile ya UHPC ndi 12.2MPa, ndipo mphamvu yamakomedwe ndi 103%. Ndi kuwonjezeka kwina kwa HPMC zomwe zili mu chitsanzocho, axial The central tensile mphamvu yamtengo wapatali inayamba kutsika kwambiri. Pamene HPMC zomwe zili mu chitsanzocho zinali 0.75% ndi 1.00%, mphamvu zowonongeka zinali 94% ndi 78%, motero, zomwe zinali zochepa kuposa mphamvu ya axial tensile ya UHPC popanda HPMC.

Kuchokera paubwenzi pakati pa mfundo zazikuluzikulu za zitsanzo za UHPC pa masiku 7 ndi masiku 28 ndi zomwe zili mu HMPC, zikhoza kuwoneka kuti mfundo zowonongeka zimakhala zosasinthika ndi kuwonjezeka kwa cellulose ether pachiyambi, ndi pamene zili mu cellulose ether imafika pa 0.50% ndipo kenako idayamba kutsika mwachangu.

Zotsatira za kuchuluka kowonjezera kwa HPMC pa mphamvu ya axial tensile komanso kufunikira kokhazikika kwa zitsanzo za UHPC kukuwonetsa chizolowezi chosunga mosasinthika kenako ndikuchepera. Chifukwa chachikulu n'chakuti HPMC akhoza mwachindunji kupangidwa pakati hydrated simenti particles A wosanjikiza madzi polima kusindikiza filimu amasewera kusindikiza, kuti madzi ena amasungidwa mu UHPC, amene amapereka madzi zofunika kuti mosalekeza chitukuko cha hydration zina. wa simenti, potero kupititsa patsogolo mphamvu ya simenti. Kuwonjezera kwa HPMC kumapangitsanso Kugwirizana kwa UHPC kumapangitsa kuti slurry ikhale yosinthasintha, zomwe zimapangitsa UHPC kuti igwirizane ndi kuchepa ndi kusinthika kwa zinthu zoyambira, ndipo imapangitsa kuti mphamvu ya UHPC ikhale yolimba. Komabe, zomwe zili mu HPMC zikadutsa mtengo wofunikira, mpweya wolowa umakhudza mphamvu ya chitsanzocho. Zotsatira zoyipa zidayamba kutsogola pang'onopang'ono, ndipo kulimba kwa axial komanso kufunikira kwamphamvu kwachitsanzocho kunayamba kuchepa.

3. Mapeto

1) HPMC imatha kusintha kwambiri magwiridwe antchito a kutentha kwanthawi zonse kuchiritsa UHPC, kutalikitsa nthawi yake yolumikizana ndikuchepetsa kutayika kwamadzi kwa UHPC wosakanikirana pakapita nthawi.

2) Kuwonjezera kwa HPMC kumayambitsa tinthu tating'onoting'ono tating'onoting'ono panthawi yomwe ikugwedezeka kwa slurry. Ngati kuchuluka kwake kuli kokulirapo, thovulo lidzasonkhanitsa mochulukira ndikupanga thovu lalikulu. Dothi lotayirira limakhala logwirizana kwambiri, ndipo thovulo silingathe kusefukira ndi kuphulika. Ma pores a UHPC owuma amachepetsa; kuwonjezera apo, polima wosinthika wopangidwa ndi HPMC sangathe kupereka chithandizo chokhazikika pamene akupanikizika, ndipo mphamvu zopondereza ndi zosinthika zimachepetsedwa kwambiri.

3) Kuphatikiza kwa HPMC kumapangitsa pulasitiki ya UHPC komanso yosinthika. Mphamvu ya axial tensile komanso mtengo womaliza wa zitsanzo za UHPC sizisintha ndi kuchuluka kwa zomwe zili mu HPMC, koma zomwe zili mu HPMC zikadutsa mtengo wake, Kulimba kwa axial komanso kukhazikika komaliza kumachepetsedwa kwambiri.

4) Pokonzekera kutentha kwabwino kuchiritsa UHPC, mlingo wa HPMC uyenera kuyendetsedwa mosamalitsa. Mlingo ukakhala 0.50%, ubale pakati pa magwiridwe antchito ndi zida zamakina za kutentha kwanthawi zonse kuchiritsa UHPC zitha kulumikizidwa bwino.