Cov nyhuv ntawm cellulose ether ntawm cov yas dawb shrinkage ntawm mortar

Cov nyhuv ntawm cellulose ether ntawm cov yas dawb shrinkage ntawm mortar

Lub sensor tsis sib cuag nrog laser hloov pauv tau siv los ntsuas tsis tu ncua cov yas dawb shrinkage ntawm HPMC hloov cov cement mortar nyob rau hauv cov xwm txheej ceev, thiab nws cov dej poob tau pom nyob rau tib lub sijhawm. HPMC cov ntsiab lus thiab cov yas tsis muaj shrinkage thiab dej poob tus nqi regression qauv tau tsim raws li. Cov txiaj ntsig tau pom tias cov yas dawb shrinkage ntawm cov cement mortar txo qis linearly nrog qhov nce ntawm HPMC cov ntsiab lus, thiab cov yas dawb shrinkage ntawm cement mortar tuaj yeem txo los ntawm 30% -50% nrog qhov sib ntxiv ntawm 0.1% -0.4% (feem ntau) HPMC. Nrog rau qhov nce ntawm HPMC cov ntsiab lus, cov dej poob tus nqi ntawm cov cement mortar kuj linearly txo. Cov dej poob ntawm cov cement mortar tuaj yeem raug txo los ntawm 9% ~ 29% nrog qhov sib ntxiv ntawm 0.1% ~ 0.4% HPMC. Cov ntsiab lus ntawm HPMC muaj qhov pom tseeb kev sib raug zoo nrog dawb shrinkage thiab dej poob tus nqi ntawm mortar. HPMC txo cov yas shrinkage ntawm cement mortar vim nws cov dej tuav tau zoo heev.

Cov lus tseem ceeb:Tom ntej: Methyl Hydroxypropyl Cellulose Ether (HPMC); mortar; Yas tsis muaj shrinkage; Tus nqi poob dej; Regression qauv

Piv nrog cov cement pob zeb, cov cement mortar tawg yooj yim dua. Ntxiv rau qhov tseem ceeb ntawm cov ntaub ntawv raw lawv tus kheej, qhov kev hloov ntawm sab nraud kub thiab av noo yuav ua rau cov cement mortar poob dej sai, ua rau kom nrawm nrawm. Txhawm rau daws qhov teeb meem ntawm cement mortar cracking, feem ntau yog daws los ntawm kev ntxiv dag zog rau kev kho thaum ntxov, siv tus neeg sawv cev nthuav dav thiab ntxiv cov fiber ntau.

Raws li cov khoom siv polymer feem ntau siv hauv kev lag luam cement mortar, cellulose ether yog cellulose derivative tau los ntawm cov tshuaj tiv thaiv ntawm cov nroj tsuag cellulose thiab caustic soda. Zhan Zhenfeng et al. qhia tau tias thaum cov ntsiab lus ntawm cellulose ether (loj feem) yog 0% ~ 0.4%, cov dej tuav tus nqi ntawm cov cement mortar muaj ib tug zoo linear kev sib raug zoo nrog cov ntsiab lus ntawm cellulose ether, thiab siab dua cov ntsiab lus ntawm cellulose ether, qhov ntau dua. dej tuav tus nqi. Methyl hydroxypropyl cellulose ether (HPMC) yog siv rau hauv cov cement mortar los txhim kho nws cov cohesiveness thiab cohesiveness vim nws txoj kev sib raug zoo, kev ncua kev ruaj ntseg thiab cov khoom tuav dej.

Daim ntawv no siv cov yas dawb shrinkage ntawm cov cement mortar raws li cov khoom siv kuaj, kawm txog cov txiaj ntsig ntawm HPMC ntawm cov yas dawb shrinkage ntawm cov cement mortar, thiab tshuaj xyuas seb vim li cas HPMC txo cov yas dawb shrinkage ntawm cement mortar.

1. Cov ntaub ntawv raw thiab cov txheej txheem xeem

1.1 Cov khoom siv raw

Cov cement siv hauv kev sim yog conch hom 42.5R zoo tib yam Portland cement tsim los ntawm Anhui Conch Cement Co., LTD. Nws thaj chaw tshwj xeeb yog 398.1 m² / kg, 80μm sieve residue yog 0.2% (qhov loj me); HPMC yog muab los ntawm Shanghai Shangnan Trading Co., LTD. Nws viscosity yog 40 000 mPa·s, cov xuab zeb yog nruab nrab coarse daj xuab zeb, lub fineness modulus yog 2.59, thiab qhov siab tshaj particle loj yog 5 hli.

1.2 Cov txheej txheem xeem

1.2.1 Plastic free shrinkage test method

Cov yas dawb shrinkage ntawm cov cement mortar tau sim los ntawm cov khoom siv sim piav qhia hauv cov ntaub ntawv. Qhov sib piv ntawm cov cement rau xuab zeb ntawm qhov ntsuas qhov ntsuas yog 1: 2 (qhov loj ntawm qhov sib piv), thiab qhov sib piv ntawm cov dej rau cement yog 0.5 (qhov loj piv). Ntsuas cov khoom siv raw raws li qhov sib xyaw sib xyaw, thiab tib lub sijhawm ntxiv rau lub lauj kaub sib xyaw kom qhuav stirring rau 1min, ces ntxiv dej thiab ntxiv stirring rau 2 feeb. Ntxiv li 20g ntawm cov tshuaj tsw qab (dawb granulated qab zib), sib tov zoo, ncuav lub cement mortar sab nraud los ntawm nruab nrab ntawm cov ntoo pwm nyob rau hauv ib tug kauv puab, ua rau nws npog lub qis ntoo pwm, smooth nws nrog ib tug spatula, thiab ces siv pov tseg. yas zaj duab xis kom kis tau rau ntawm qhov chaw ntawm cov cement mortar, thiab tom qab ntawd ncuav cov tshuaj mortar rau ntawm daim ntaub yas hauv tib txoj kev los sau cov pwm sab saud. Thiab tam sim ntawd nrog rau qhov ntev ntawm cov ntaub ntub dej txhuas phaj ntev dua qhov dav ntawm cov pwm pwm, nrawm nrawm nrog rau sab ntev ntawm cov pwm pwm.

Microtrak II LTC-025-04 laser displacement sensor tau siv los ntsuas cov yas dawb shrinkage ntawm cement mortar slab. Cov kauj ruam yog raws li nram no: Ob lub hom phiaj kev xeem (cov paib me me) tau muab tso rau hauv nruab nrab txoj hauj lwm ntawm cov cement mortar phaj, thiab qhov kev ncua deb ntawm ob lub hom phiaj yog 300 hli. Tom qab ntawd, ib lub thav duab hlau ruaj nrog laser hloov pauv sensor tau muab tso rau saum toj ntawm cov qauv, thiab kev nyeem thawj zaug ntawm lub laser thiab cov khoom ntsuas tau raug kho kom nyob hauv qhov ntsuas 0. Thaum kawg, 1000W iodine tungsten teeb ntawm li 1.0m saum ntoo pwm thiab lub kiv cua hluav taws xob ntawm li 0.75m saum ntoo pwm (cua nrawm yog 5m / s) tau qhib tib lub sijhawm. Cov yas tsis muaj shrinkage kuaj txuas ntxiv mus txog thaum cov qauv qis qis kom ruaj khov. Thaum lub sij hawm tag nrho cov kev xeem, qhov kub yog (20 ± 3) ℃ thiab cov txheeb ze humidity yog (60 ± 5) %.

1.2.2 Kev ntsuas dej evaporation tus nqi

Xav txog qhov cuam tshuam ntawm cov khoom siv cement-based ntawm cov dej evaporation tus nqi, cov ntaub ntawv siv cov qauv me me los simulate cov dej evaporation tus nqi ntawm cov qauv loj, thiab kev sib raug zoo ntawm qhov sib piv Y ntawm cov dej evaporation tus nqi ntawm cov phaj loj cement mortar. thiab me-phaj cement mortar thiab lub sij hawm t(h) yog raws li nram no: y = 0.0002 t + 0.736

2. Cov txiaj ntsig thiab kev sib tham

2.1 Kev cuam tshuam ntawm HPMC cov ntsiab lus ntawm cov yas dawb shrinkage ntawm cov cement mortar

Los ntawm cov txiaj ntsig ntawm HPMC cov ntsiab lus ntawm cov yas dawb shrinkage ntawm cov cement mortar, nws tuaj yeem pom tias cov yas dawb shrinkage ntawm cov cement mortar feem ntau tshwm sim hauv 4h ntawm kev nrawm nrawm, thiab nws cov yas dawb shrinkage nce linearly nrog lub sijhawm txuas ntxiv. Tom qab 4h, cov yas dawb shrinkage nce mus txog 3.48mm, thiab qhov nkhaus yuav ruaj khov. Cov yas dawb shrinkage nkhaus ntawm HPMC cement mortar yog tag nrho nyob rau hauv qab cov yas dawb shrinkage nkhaus ntawm cov cement mortar zoo tib yam, qhia tias cov yas dawb shrinkage curves ntawm HPMC cement mortar yog tag nrho me dua li cov cement mortar. Nrog rau qhov nce ntawm HPMC cov ntsiab lus, cov yas dawb shrinkage ntawm cement mortar maj mam txo. Piv nrog rau cov cement mortar zoo tib yam, cov yas tsis muaj shrinkage ntawm HPMC cement mortar tov nrog 0.1% ~ 0.2% (cov feem ntau) txo los ntawm li 30%, txog 2.45 hli, thiab cov yas dawb shrinkage ntawm 0.3% HPMC cement mortar txo los ntawm 40 %. Yog hais txog 2.10mm, thiab cov yas dawb shrinkage ntawm 0.4% HPMC cement mortar txo los ntawm 50%, uas yog hais txog 1.82mm. Yog li ntawd, nyob rau tib lub sij hawm ceev nrooj tawg, cov yas dawb shrinkage ntawm HPMC cement mortar yog qis dua li ntawm cov cement mortar zoo tib yam, qhia tias kev koom ua ke ntawm HPMC tuaj yeem txo cov yas dawb shrinkage ntawm cov cement mortar.

Los ntawm cov txiaj ntsig ntawm HPMC cov ntsiab lus ntawm cov yas dawb shrinkage ntawm cov cement mortar, nws tuaj yeem pom tias nrog kev nce ntawm HPMC cov ntsiab lus, cov yas dawb shrinkage ntawm cement mortar maj mam txo. Kev sib raug zoo ntawm cov yas dawb shrinkage (s) ntawm cov cement mortar thiab HPMC cov ntsiab lus (w) tuaj yeem haum los ntawm cov qauv hauv qab no: S = 2.77-2.66 w

HPMC cov ntsiab lus thiab cov cement mortar yas dawb shrinkage linear regression variance tsom xam cov txiaj ntsig, qhov twg: F yog qhov txheeb cais; Sig. Sawv cev rau theem qhov tseem ceeb.

Cov txiaj ntsig tau pom tias qhov sib txheeb coefficient ntawm qhov sib npaug yog 0.93.

2.2 Kev cuam tshuam ntawm HPMC cov ntsiab lus ntawm cov dej poob ntawm cov cement mortar

Raws li qhov xwm txheej ntawm kev nrawm, nws tuaj yeem pom los ntawm kev hloov pauv ntawm cov dej poob ntawm cov cement mortar nrog cov ntsiab lus ntawm HPMC, cov dej poob ntawm cov cement mortar nto maj mam txo nrog qhov nce ntawm HPMC cov ntsiab lus, thiab qhov pib nthuav tawm qhov poob qis. Piv nrog rau cov dej poob ntawm cov cement mortar zoo tib yam, thaum HPMC cov ntsiab lus yog 0.1%, 0.2%, 0.3%, 0.4%, ntsig txog, Cov dej poob ntawm cov cement mortar loj poob los ntawm 9.0%, 12.7%, 22.3% thiab 29,4% ib. Kev koom ua ke ntawm HPMC txo cov dej poob ntawm cov cement mortar thiab ua rau cov dej ntau ntxiv hauv cov dej ntawm cov cement mortar, yog li tsim kom muaj zog tensile txaus los tiv thaiv qhov kev pheej hmoo tawg los ntawm ib puag ncig sab nraud.

Kev sib raug zoo ntawm cov cement mortar dej poob tus nqi (d) thiab HPMC cov ntsiab lus (w) tuaj yeem haum raws li cov qauv hauv qab no: d = 0.17-0.1w

Cov kab rov tav regression variance tsom xam cov txiaj ntsig ntawm HPMC cov ntsiab lus thiab cov cement mortar dej poob tus nqi qhia tau hais tias qhov sib txheeb coefficient ntawm qhov sib npaug yog 0.91, thiab qhov kev sib raug zoo yog pom tseeb.

3. Cov lus xaus

Cov yas dawb shrinkage ntawm cov cement mortar txo qis nrog qhov nce ntawm cov ntsiab lus ntawm HPMC. Cov yas dawb shrinkage ntawm cement mortar nrog 0.1% ~ 0.4% HPMC txo los ntawm 30% ~ 50%. Cov dej poob ntawm cov cement mortar txo qis nrog qhov nce ntawm HPMC cov ntsiab lus. Cov dej poob ntawm cov cement mortar nrog 0.1% ~ 0.4% HPMC txo los ntawm 9.0% ~ 29.4%. Cov yas dawb shrinkage thiab dej poob tus nqi ntawm cov cement mortar yog linear nrog cov ntsiab lus ntawm HPMC.