Mechanical Properties yeCellulose Eteri Yakagadziridzwa yeSimende Mortar

Iyo yakagadziridzwa simende dhaka ine mvura-simende reshiyo ye0.45, lime-jecha reshiyo ye1: 2.5, uye cellulose ether ine viscosities yakasiyana ye0%, 0.2%, 0.4%, 0.6%, 0.8%, uye 1.0% yakagadzirwa. . Nekuyera ma mechanical properties ye simenti dhaka uye nekucherechedza microscopic morphology, mhedzisiro yeHEMC pasimba rekumanikidza, simba rekunyungudika uye kusimba kwechisungo chemodified sement mortar chakadzidzwa. Mhedzisiro yetsvagiridzo inoratidza kuti: nekuwedzera kweHEMC yemukati, iyo inodzvinyirira simba reakagadziridzwa dhaka pamazera akasiyana anoderera zvichienderera, uye kuderera kwemhando kunoderera uye kunowanzo kuve munyoro; kana izvo zvakafanana zve cellulose ether zvawedzerwa, Iyo yekumanikidza simba ye cellulose ether yakagadziridzwa dhaka ine maviscosities akasiyana ndeye: HEMC20 HEMC10>HEMC5.

Mazwi akakosha:cellulose ether; simende dhaka; compressive simba; flexural simba; bond simba

1 Nhanganyaya

Panguva ino, kudiwa kwepagore kwedhaka munyika kunodarika matani mazana maviri emamiriyoni, uye kudiwa kwemaindasitiri kuri kuramba kuchikwira. Parizvino, dhaka resimende rechinyakare rine hurema hwakadai sekubuda ropa, delamination, kuomeswa kukuru, kusamira zvakanaka, kushomeka kwechisungo chesimba, uye kusakwana kwemvura nekuda kwekurasikirwa kwemvura, izvo zvakaoma kugadzirisa, kwete kungokonzera kukanganisa kwekuvaka, asiwo kutungamirira. kuomesa Phenomena senge dhaka kuputika, pulverization, kudurura, uye gollowing zvinoitika.

Seimwe yeanonyanya kushandiswa admixtures ekutengesa dhaka, cellulose ether ine mabasa ekuchengetedza mvura, kukora uye kudzoreredza, uye inogona kushandiswa kuvandudza hunhu hwesimende dhaka senge kushanda, kuchengetedza mvura, kuita bonding, uye kuseta nguva. , zvakadai sekuwedzera zvakanyanya simende. Iyo tensile bond simba redhaka ichaderedzwa, asi iyo yekumanikidza simba, flexural simba uye elastic modulus yesamende dhaka ichaderedzwa. Zhang Yishun nevamwe vakadzidza nezve methyl cellulose ether uye hydroxypropyl methyl cellulose ether pane zvinhu zvedhaka. Zvigumisiro zvakaratidza kuti: zvose cellulose ethers zvinogona kuvandudza kuchengetwa kwemvura kwedhaka, uye simba rekushandura uye Simba rekumanikidzika rinoderera mumadhigirii akasiyana, nepo kupeta kwehuwandu uye simba rekubatanidza redhaka rinowedzera mumadhigirii akasiyana, uye shrinkage kushanda kwedhaka kunogona. kuvandudzwa. AJenni, R. Zurbriggen, nezvimwewo vakashandisa nzira dzemazuva ano dzekuedza nekuongorora kuti vadzidze kupindirana kwezvinhu zvakasiyana-siyana mu cellulose ether yakagadziridzwa yakaonda-layer adhesive mortar system, uye akaona kuti cellulose ether neCa (OH) yakaonekwa pedyo nepamusoro pedhaka. . 2, zvichiratidza kutama kwe cellulose ethers mune sement-based materials.

Mubepa rino, uchishandisa nzira dzekuyedza dhaka dzakadai se compressive kuramba, kuchinjika kuramba, kusungirirana, uye SEM microscopic chitarisiko, pesvedzero ye cellulose ether simende dhaka pamichina zvinhu senge compressive simba, flexural resistance, uye bond simba pamazera akasiyana inodzidzwa, uye zvinotsanangurwa. nzira yayo yekuita.

2. Raw zvinhu uye nzira dzekuyedza

2.1 Raw zvinhu

2.1.1 Simende

Yakajairika laurate simende inogadzirwa naWuhan Huaxin Cement Co., Ltd., modhi P 042.5 (GB175-2007), ine density ye3.25g/cm.³ uye yakananga nzvimbo ye4200cm²/g.

2.1.2 Hydroxypropyl methylcellulose ether

Thehydroxyethyl methyl cellulose etherinogadzirwa neHercules Group yekuUnited States ine viscosities ye50000MPa/s, 100000MPa/s, uye 200000MPa/s mu2% mhinduro pa25.°C, uye zvipfupiso zvinotevera HEMC5, HEMC10, uye HEMC20.

2.2 Nzira yekuedza

a. Compressive simba remodified mortar

Kusimba kwekusimba kwemavara egirinhi emuviri kwakaedzwa neTYE-300 compressive simba muchina kubva kuWuxi Jianyi Instrument Co., Ltd. Muyero wekurodha i0.5 kN/s. Iyo yekumanikidza simba bvunzo inoitwa zvinoenderana neGB/T17671-1999 "Cement Mortar Strength Test Method (ISO Method)".

Netsanangudzo, iyo formula yekuverenga iyo yekumanikidza simba regirinhi muviri ndeiyi:

Rc=F/S

Iko Rc-kumanikidza simba, MPa;

F-iyo yekukundikana mutoro unoshanda pane muenzaniso, kN;

S-nzvimbo yekumanikidza, m².

Netsanangudzo, fomula yekuverenga iyo flexural simba regirinhi muviri ndeiyi:

Rf= (3P× L)/(2b× h²) =0.234×P

Mune formula, Rf-flexural simba, MPa;

P-iyo yekukundikana mutoro unoshanda pane muenzaniso, kN;

L-chinhambwe chiri pakati penzvimbo dzemasilinda anotsigira, kureva, 10cm;

b,h-hupamhi uye urefu hwemuchinjikwa-chikamu chemuviri wekuedza, zvose zviri 4cm.

b. Tensile bond simba remodified simende mortar

Shandisa ZQS6-2000 Adhesive Brick Adhesive Strength Detector kuyera simba rekunamira, uye kukurumidza kumhanya i2mm/min. Muedzo wesimba rekubatanidza wakaitwa maererano neJC/T985-2005 "Cement-based self-leveling mortar for ground".

Netsanangudzo, iyo formula yekuverenga iyo bond simba regirinhi muviri ndeiyi:

P=F/S

Mune formula, P-kusimba kwechisungo, MPa;

F-yakanyanya kutadza mutoro, N;

S-nzvimbo yekubatanidza, mm².

3. Migumisiro uye nhaurirano

3.1 Kudzvinyirira simba

Kubva pakusimba kwesimba remhando mbiri dze cellulose ether yakagadziridzwa madhaka ane viscosities akasiyana pamazera akasiyana, zvinogona kuonekwa kuti nekuwedzera kweHEMC yemukati, simba rekumanikidza re cellulose ether yakagadziridzwa madhaka pazera rakasiyana (3d, 7d uye 28d) yakaderera. zvakanyanya. Zvinonyanya kuderera uye zvishoma nezvishoma zvakadzikama: apo zvinyorwa zveHEMC zvakanga zvisingasviki 0.4%, simba rekumanikidzika rakaderera zvikuru kana richienzaniswa nemuenzaniso usina chinhu; apo izvo zveHEMC zvaive 0.4% ~ 1.0%, maitiro ekuderera kwesimba rekumanikidza akadzikira. Kana iyo cellulose ether yemukati yakakura kupfuura 0.8%, simba rekumanikidza re7d uye 28d zera rakaderera pane iro reiyo isina chinhu sampu pazera re3d, nepo simba rekumanikidza remodified dhaka 3d rinenge razero, uye sampuli iri. kudzvanywa zvishoma Pakarepo yakapwanyika, mukati mune upfu, uye density yakaderera zvakanyanya.

Mhedzisiro yeHEMC imwechete pamusoro pesimba rekumanikidza revhu rakagadziridzwa pamazera akasiyana rakasiyanawo, zvichiratidza kuti simba rekumanikidza re28d rinoderera nekuwedzera kweHEMC zvinyorwa kupfuura izvo zve7d uye 3d. Izvi zvinoratidza kuti kukanganisa kweHEMC kwakagara kuripo nekuwedzera kwezera, uye kukanganisa kweHEMC hakuna kukanganiswa nekuderedzwa kwemvura muhurongwa kana kufambira mberi kwe hydration reaction, zvichiita mukukura kwesimba rekumanikidza. yedhaka yakagadziridzwa iri diki zvakanyanya pane iyo isina Mortar samples yakasanganiswa neHEMC.

Kubva pakuchinja kwe curve yekumanikidza simba re cellulose ether yakagadziridzwa dhaka pamazera akasiyana, zvinogona kuonekwa kuti kana huwandu hwakafanana hwe cellulose ether hwawedzerwa, simba rekumanikidza re cellulose ether yakagadziridzwa dhaka ine viscosities yakasiyana ndeye: HEMC20 HEMC10>HEMC5. Izvi zvinodaro nekuti HEMC ine huwandu hwepamusoro hwepolymerization ine mhedzisiro yakakura pakuderedzwa kwesimba rekumanikidza redhaka kupfuura HEMC ine yakaderera dhigirii yepolymerization, asi simba rekumanikidza revhu rakagadziridzwa rakasanganiswa neHEMC rakaderera kupfuura iro re blank mortar pasina HEMC.

Zvinhu zvitatu zvinotevera zvinotungamira mukudzikira kwesimba rekumanikidza redhaka rakagadziridzwa: kune rumwe rutivi, nekuti inonyungudika mvura HEMC macromolecular network inovhara masimende, CSH gel, calcium oxide, calcium aluminate hydrate uye zvimwe zvimedu uye isina mvura. particles Pamusoro pepamusoro, kunyanya mukutanga kwe simenti hydration, kushambadza pakati pe calcium aluminate hydrate uye HEMC inoderedza hydration reaction ye calcium aluminate, zvichiita kuti kuderera kukuru kwesimba rekumanikidza. Iko kudzoreredza mhedzisiro yedhaka rinogara riri pachena, izvo zvinoratidza kuti kana zvirimo zveHEMC20 zvinosvika 0.8% ~ 1%, iyo 3d simba reakagadziridzwa dhaka sampuli zero; kune rumwe rutivi, hydrated HEMC solution ine viscosity yakakwirira, uye Panguva yekusanganiswa kwevhu, inogona kusanganiswa nemhepo kuti iite nhamba yakawanda yemhepo inoputika, zvichiita kuti pave nenhamba yakawanda yevoid mumatope akaoma. , uye simba rekumanikidza remuenzaniso rinoderera nekuenderera mberi nekuwedzera kweHEMC zvinyorwa uye kuwedzera kwechidimbu chepolymerization; Iyo dhaka system inongowedzera kuchinjika kwedhaka uye haigone kutamba basa rerutsigiro rwakaomarara, saka iyo yekumanikidza simba inoderedzwa.

3.2 Flexural simba

Kubva pakusimba kwemasimba maviri akasiyana-siyana e-viscosity cellulose ether yakagadziridzwa madhaka pamakore akasiyana, zvinogona kuonekwa kuti zvakafanana nekushanduka kwesimba rekumanikidzika remarara akagadziridzwa, simba rekushandura re cellulose ether modified mortar inoderera zvishoma nezvishoma nekuwedzera kweHEMC content.

Kubva pakuchinja kwe flexural simba re cellulose ether yakagadziridzwa dhaka pamazera akasiyana, zvinogona kuonekwa kuti kana zvinyorwa zve cellulose ether zvakafanana, simba reflexural reHEMC20 rakagadziridzwa dhaka sampuli yakaderera zvishoma pane yeHEMC10 yakagadziridzwa dhaka sampuli, nepo kana zvirimo zveHEMC zviri 0.4% ~ 0.8%, iyo 28d flexural simba inoshandura macurves ezviviri zvinenge zvakabatana.

Kubva pane shanduko yekuchinja kwesimba rekuchinjika kwe cellulose ether yakagadziridzwa dhaka pamazera akasiyana, zvinogona zvakare kuonekwa kuti shanduko musimba rekuchinjika revhu rakagadziridzwa ndeye: HEMC5

3.3 Bond simba

Inogona kuonekwa kubva pakusiyana-siyana kwechisungo chesimba rematatu e-cellulose ether yakagadziridzwa madhaka pamakore akasiyana-siyana kuti simba rezvisungo zvevhu rakagadziridzwa rinowedzera nekuwedzera kweHEMC zvinyorwa uye zvishoma nezvishoma zvinowanzoita kugadzikana. Nekuwedzera kwezera, kusimba kwechisungo chedhaka yakagadziridzwa yakaratidzawo kuwedzera kwemaitiro.

Inogona kuonekwa kubva ku28-day bond simba shanduko curves yematatu cellulose ether yakagadziridzwa madhaka ayo kusimba kwechisungo chedhaka yakagadziridzwa kunowedzera pamwe nekuwedzera kweHEMC zvinyorwa, uye zvishoma nezvishoma zvinowanzoita kugadzikana. Panguva imwecheteyo, nekuwedzera kwedhigirii yepolymerization ye cellulose ether, shanduko yesimba rezvisungo zvevhu rakagadziridzwa ndeye: HEMC20> HEMC10> HEMC5.

Izvi zvinokonzerwa nekuiswa kwehuwandu hwema pores muhutu hwakagadziridzwa nehupamhi hweHEMC, zvichiita kuti kuwedzerwa kweporosity yemuviri wakaoma, kuderera kwehuwandu hwechimiro, uye kukura kunonoka kwesimba rezvisungo. ; muyedzo yakaoma, kuputsika kwakaitika mudhaka rakagadziridzwa Mukati, hapana kuputsika panzvimbo yekubatana pakati pevhu rakagadziridzwa uye substrate, iyo inoratidza kuti simba rezvisungo pakati pevhu rakagadziridzwa uye substrate yakakura kudarika iyo yakaoma. modified mortar. Nekudaro, kana huwandu hweHEMC hwakaderera (0% ~ 0.4%), iyo-inonyungudika mvura HEMC mamorekuru anogona kuvhara nekuputira pane hydrated simende zvimedu, uye kuumba firimu repolymer pakati pezvimedu zvesamende, izvo zvinowedzera kushanduka uye kuchinjika. dhaka rakagadziridzwa. Plasticity, uye nekuda kwekuchengetedza kwemvura kwakanakisa kweHEMC, dhaka rakagadziridzwa rine mvura yakakwana ye hydration reaction, iyo inogonesa kukura kwesimba resimende, uye kusimba kwechisungo chemodified simende dhaka rinowedzera mutsara.

3.4 SEM

Kubva pamifananidzo yeSEM ​​yekuenzanisa isati yasvika uye shure kweserulosi ether yakagadziridzwa dhaka, zvinogona kuonekwa kuti zvipembenene pakati pezviyo zvekristani mudhaka risina kugadziriswa zvakakura, uye zvishoma zvemakristasi zvinoumbwa. Mudhaka yakagadziridzwa, makristasi anokura zvakakwana, kubatanidzwa kwe cellulose ether kunovandudza kushandiswa kwemvura yemvura yedhaka, simiti yakazara hydrated, uye zvigadzirwa zve hydration zviri pachena.

Izvi zvinodaro nekuti cellulose ether yakarapwa neakakosha etherification process, ine yakanakisa kupararira uye kuchengetedza mvura. Mvura yacho inosunungurwa zvishoma nezvishoma kwenguva yakareba, mvura shomanana chete inopukunyuka kubva kune capillary pores nekuda kwekuoma uye evaporation, uye yakawanda yemvura inonyura nesamende kuti ivimbise simba rekugadzirisa simenti dhaka.

4 Mhedziso

a. Sezvo zvinyorwa zveHEMC zvichiwedzera, simba rekumanikidzika revhu rakagadziridzwa pamazera akasiyana rinoderera nguva dzose, uye huwandu hwekuderedza hunoderera uye hunoita kuti huve hwakatsetseka; apo zvinyorwa zve cellulose ether zvakakura kudarika 0.8%, 7d uye 28d Simba rekumanikidzika re 3d-aged blank sample yakaderera pane yemuenzaniso usina chinhu, nepo 3d-aged compressive simba yemodified mortar inenge zero. Sample inotsemuka kana ikadzvanywa zvishoma, uye mukati mune upfu nekudzikira.

b. Kana huwandu hwakafanana hwe cellulose ether hwawedzerwa, iyo inomanikidza simba re cellulose ether yakagadziridzwa dhaka ine maviscosity akasiyana inoshanduka seizvi: HEMC20 HEMC10>HEMC5.

c. Simba rekushanduka kwe cellulose ether yakagadziridzwa dhaka inoderera zvishoma nezvishoma nekuwedzera kweHEMC yezvinyorwa. Shanduko yesimba rekuchinjika revhu rakagadziridzwa ndeiyi: HEMC5

d. Simba rekubatanidza revhu rakagadziridzwa rinowedzera nekuwedzera kweHEMC zvinyorwa, uye zvishoma nezvishoma zvinowanzoita kugadzikana. Panguva imwecheteyo, nekuwedzera kwedhigirii yepolymerization ye cellulose ether, shanduko yesimba rezvisungo zvevhu rakagadziridzwa ndeye: HEMC20> HEMC10> HEMC5.

e. Mushure mokunge cellulose ether yakasanganiswa mudhaka resimende, kristaro inokura zvakakwana, pores pakati pezviyo zvekristani inoderedzwa, uye simenti yakazara nemvura, iyo inovimbisa kumanikidzika, kushanduka uye kusungirirwa kwesimba resimenti.