Properties of Cement Paste Yakagadziriswa neCellulose Ether

Nekuyera ma mechanical properties, chiyero chekuchengetedza mvura, kuisa nguva uye kupisa kwe hydration ye cellulose ether ine viscosities yakasiyana mune zvakasiyana-siyana zvesimende paste, uye kushandisa SEM kuongorora hydration zvigadzirwa, mhedzisiro ye cellulose ether pakushanda kwesamende paste yaive. akadzidza. mutemo wepesvedzero. Mhedzisiro yacho inoratidza kuti kuwedzera kwe cellulose ether kunogona kunonoka simende hydration, kunonoka kuomesa simende uye kuseta, kuderedza hydration kupisa kusunungurwa, kurebesa kutaridzika kweiyo hydration tembiricha peak, uye kudzoreredza mhedzisiro kunowedzera nekuwedzera kwedosi uye viscosity. Cellulose ether inogona kuwedzera chiyero chekuchengetedza mvura yedhaka, uye inogona kuvandudza kuchengetwa kwemvura yedhaka neyakaonda-layer structure, asi kana zvinyorwa zvinopfuura 0.6%, kuwedzera kwemvura yekuchengetedza mvura hakuna kukosha; zviri mukati uye viscosity ndizvo zvinhu zvinotarisa iyo cellulose yakagadziridzwa simende slurry. Mukushandiswa kwe cellulose ether yakagadziridzwa dhaka, iyo dosage uye viscosity inofanirwa kutariswa zvakanyanya.

Mazwi akakosha:cellulose ether; chipimo chemushonga; retardation; kuchengetedza mvura

Dura rekuvaka chimwe chezvinhu zvinodikanwa zvekuvaka pazvirongwa zvekuvaka. Mumakore achangopfuura, nehukuru-hukuru hwekushandisa kwemadziro ekudzivirira zvinhu uye kuvandudzwa kwe-anti-crack uye anti-seepage zvinodiwa kumadziro ekunze, zvinodiwa zvakakwirira zvakaiswa pamberi pekupikisa kuputika, kushanda kwekubatanidza uye kuita kwekuvaka kwedhaka. Nekuda kwekushomeka kwehombe yekuomesa shrinkage, kusamira zvakanaka, uye kushomeka kwechisungo chesimba, dhaka rechinyakare kazhinji harigone kusangana nezvinodiwa zvekuvaka, kana kukonzera matambudziko sekudonha kwezvinhu zvekushongedza. Zvakadai sekupura dhaka, nekuti dhaka rinorasikirwa nemvura nekukurumidza, nguva yekumisikidza uye kuomesa inopfupikiswa, uye matambudziko akadai sekutsemuka uye maburi anoitika panguva yekuvaka kwakakura, izvo zvinokanganisa zvakanyanya kunaka kweprojekiti. Iyo dhaka yechinyakare inorasa mvura nekukurumidza uye simende hydration haina kukwana, zvichiita kuti pave nenguva pfupi yekuvhurwa kwesamende, inova kiyi yekukanganisa kushanda kwedhaka.

Cellulose ether ine yakanaka thickening uye kuchengetedza mvura mhedzisiro, uye yakashandiswa zvakanyanya mumunda wedhaka, uye yave musanganiswa unokosha kuvandudza kuchengetwa kwemvura kwedhaka uye kupa kuita kwekuvaka, zvinobudirira kuderedza kuvaka uye kushandiswa kwekare kwechinyakare dhaka. . Dambudziko rekurasikirwa kwemvura mukati mepakati. Cellulose inoshandiswa mudhaka inowanzobatanidza methyl cellulose ether (MC), hydroxypropyl methyl cellulose (HPMC), hydroxyethyl methyl cellulose ether (HEMC), hydroxyethyl cellulose ether (HEC), etc. Pakati pavo, HPMC uye HEMC ndiyo inonyanya kushandiswa.

Iri bepa rinonyanya kuongorora mhedzisiro ye cellulose ether pakushanda (chiyero chekuchengetedza mvura, kurasikirwa kwemvura uye nguva yekumisikidza), mechanical properties (compressive simba uye tensile bond simba), hydration mutemo uye microstructure yesamende paste. Inopa tsigiro yezvimiro zve cellulose ether yakagadziridzwa simende paste uye inopa chirevo chekushandiswa kwe cellulose ether yakagadziridzwa dhaka.

1. Kuedza

1.1 Raw zvinhu

Simende: Yakajairika Portland simende (PO 42.5) simende inogadzirwa neWuhan Yadong Cement Company, ine nzvimbo chaiyo ye3500 cm.²/g.

Cellulose ether: inotengeswa hydroxypropyl methylcellulose ether (MC-5, MC-10, MC-20, viscosities ye50,000 Pa·S, 100000 Pa·S, 200000 Pa·S, zvichiteerana).

1.2 Nzira

Mechanical properties: Mukugadzira sampuli yekugadzirira, muyero we cellulose ether i 0.0% ~ 1.0% yesamende mass, uye mvura-simende reshiyo i0.4. Usati wawedzera mvura uye kubvongodza, sanganisa cellulose ether uye simende zvakaenzana. Simende paste ine saizi ye40 x 40 x 40 yakashandiswa kuongororwa.

Kugadzirisa nguva: Nzira yekuyera inoitwa maererano neGB / T 1346-2001 "Cement Standard Consistency Water Consumption, Kuisa Nguva, Kugadzikana Kwekuedza Method".

Kuchengetedzwa kwemvura: Muedzo wekuchengetwa kwemvura yesimende paste inoreva yakajairwa DIN 18555 "Nzira yekuyedza yeinorganic cementitious material mortar".

Kupisa kwe hydration: Kuedza kunotora TAM Air microcalorimeter yeTA Instrument Company yekuUnited States, uye chiyero chemvura-simende i0.5.

Hydration chigadzirwa: Kunzva mvura uye cellulose ether zvakaenzana, wobva wagadzira simende slurry, tanga nguva, tora sampuli panguva dzakasiyana dzenguva, mira hydration ine absolute ethanol yekuyedza, uye chiyero chemvura-simende i0.5.

2. Migumisiro uye nhaurirano

2.1 Mechanical properties

Kubva pane simba re cellulose ether content pane simba, zvinogona kuonekwa kuti nekuwedzera kwe MC-10 cellulose ether content, simba re 3d, 7d uye 28d zvose zvinoderera; cellulose ether inoderedza simba re28d zvakanyanya. Kubva pane simba re cellulose ether viscosity pane simba, zvinogona kuonekwa kuti kana iri cellulose ether ine viscosity ye50,000 kana 100,000 kana 200,000, simba re3d, 7d, uye 28d richaderera. Zvinogonawo kuonekwa kuti cellulose ether Viscosity haina kukosha kwesimba.

2.2 Kuisa nguva

Kubva pamigumisiro yezvinyorwa zve 100,000 viscosity cellulose ether panguva yekugadzirisa, zvinogona kuonekwa kuti nekuwedzera kwezvinyorwa zve MC-10, zvose nguva yekutanga yekugadzirisa uye nguva yekupedzisira inowedzera. Kana zvinyorwa zviri 1%, nguva yekutanga yekugadzirisa Yakasvika 510min, uye nguva yekupedzisira yakasvika 850min. Kuenzaniswa neyakashama, nguva yekutanga yekumisikidza yakawedzerwa ne210min, uye nguva yekupedzisira yekumisikidza yakawedzerwa ne470min.

Kubva kusimba re cellulose ether viscosity pakuisa nguva, zvinogona kuoneka kuti ingave MC-5, MC-10 kana MC-20, inogona kunonoka kuseta simende, asi kana ichienzaniswa neatatu cellulose ether, yekutanga kuseta. nguva uye kugadzirisa kwekupedzisira Nguva inowedzera nekuwedzera kwe viscosity. Izvi zvinodaro nekuti cellulose ether inogona kuvharwa pamusoro pemasimende, nekudaro kudzivirira mvura kuti isasangana nezvikamu zvesimende, nekudaro kunonotsa simende hydration. Iyo yakakura viscosity ye cellulose ether, iyo yakakura iyo adsorption layer iri pamusoro pezvikamu zvesimende, uye zvakanyanya kukosha kudzoreredza mhedzisiro.

2.3 Mwero wekuchengetedza mvura

Kubva kumutemo wekupesvedzera kwe cellulose ether yemukati pachiyero chekuchengetedza mvura, zvinogona kuoneka kuti nekuwedzera kwezviri mukati, mwero wekuchengetedza mvura yedhaka unowedzera, uye kana cellulose ether yemukati yakakura kupfuura 0.6%, chiyero chekuchengetedza mvura yakagadzikana munharaunda. Nekudaro, tichienzanisa matatu cellulose ethers, pane misiyano musimba re viscosity pachiyero chekuchengetedza mvura. Pasi peyero imwe chete, hukama pakati pehuwandu hwekuchengetedza mvura ndeiyi: MC-5≤MC-10≤MC-20.

2.4 Kupisa kwe hydration

Kubva pamhedzisiro ye cellulose ether mhando uye zvirimo pakupisa kwe hydration, zvinogona kuoneka kuti nekuwedzera kwe MC-10 yemukati, exothermic kupisa kwe hydration kunoderera zvishoma nezvishoma, uye nguva ye hydration tembiricha peak inoshanduka gare gare; Kupisa kwe hydration kwaivewo nesimba guru. Nekuwedzera kwe viscosity, kupisa kwe hydration kwakadzikira zvakanyanya, uye peak ye hydration tembiricha yakachinja zvakanyanya gare gare. Inoratidza kuti cellulose ether inogona kunonoka simenti hydration, uye kudzoreredza kwayo kunoenderana nemukati uye viscosity ye cellulose ether, iyo inopindirana neongororo yemhedzisiro yekuisa nguva.

2.5 Ongororo yezvigadzirwa zve hydration

Kubva pakuongororwa kweSEM kwe1d hydration chigadzirwa, zvinogona kuonekwa kuti kana 0.2% MC-10 cellulose ether yakawedzerwa, yakawanda yeunhydrated clinker uye ettringite ine crystallization iri nani inogona kuonekwa. %, makristasi ettringite akaderedzwa zvakanyanya, izvo zvinoratidza kuti cellulose ether inogona kunonoka hydration ye simenti uye kuumbwa kwe hydration zvigadzirwa panguva imwe chete. Nekuenzanisa marudzi matatu e-cellulose ethers, zvinogona kuwanikwa kuti MC-5 inogona kuita kuti crystallization ye ettringite muzvigadzirwa zve hydration zvive zvakajairika, uye crystallization ye ettringite inowanzogara. zvinoenderana nekukora kwechitubu.

3. Mhedziso

a. Kuwedzerwa kwe cellulose ether kunonotsa kunyorova kwe simenti, kunonotsa kuomarara nekugadzika kwe simenti, kuderedza kuburitswa kwekupisa kwe hydration, uye kurebesa nguva yekuonekwa kwe hydration tembiricha yepamusoro. Nekuwedzera kwedosi uye viscosity, iyo yekudzosa mhedzisiro inowedzera.

b. Cellulose ether inogona kuwedzera mwero wekuchengetedza mvura yedhaka, uye inogona kuvandudza kuchengetwa kwemvura kwedhaka neyakaonda-layer chimiro. Kuchengetwa kwayo kwemvura kwakabatana nedosi uye viscosity. Kana iyo dosi inodarika 0.6%, iyo yekuchengeta mvura haina kuwedzera zvakanyanya.