Methyl cellulose ether akan zafin jiki yana warkar da siminti mai girman gaske

Takaitawa: Ta hanyar canza abun ciki na hydroxypropyl methylcellulose ether (HPMC) a cikin yanayin zafin jiki na yau da kullun yana warkar da simintin ultra-high performance (UHPC), an yi nazarin tasirin ether na cellulose akan ruwa, saita lokaci, ƙarfin matsawa, da ƙarfin sassauƙa na UHPC. , ƙarfi mai ƙarfi da ƙarfi na lafazin da aka ƙididdige shi, kuma an bincika sakamakon. Sakamakon gwajin ya nuna cewa: ƙara ba fiye da 1.00% na ƙananan danko na HPMC ba zai shafi ruwa na UHPC ba, amma yana rage asarar ruwa a kan lokaci. , da kuma tsawaita lokacin saiti, yana inganta aikin ginin sosai; lokacin da abun ciki ya kasance ƙasa da 0.50%, tasiri akan ƙarfin matsawa, ƙarfin flexural da ƙarfin ƙarfin axial ba shi da mahimmanci, kuma da zarar abun ciki ya fi 0.50%, injinsa yana raguwa da fiye da 1/3. Idan akai la'akari da wasanni daban-daban, shawarar da aka ba da shawarar na HPMC shine 0.50%.

Mabuɗin kalmomi: matsananci-high yi kankare; ether cellulose; maganin zafin jiki na al'ada; ƙarfin matsawa; ƙarfin sassauƙa; karfin jurewa

0,Gabatarwa

Tare da saurin bunƙasa masana'antar gine-ginen kasar Sin, buƙatun da ake buƙata don aiwatar da aikin injiniya na ainihi su ma sun karu, kuma an samar da siminti mai ɗorewa (UHPC) don amsa buƙatun. A mafi kyau duka rabo daga barbashi tare da daban-daban barbashi masu girma dabam an theoretically tsara, kuma gauraye da karfe fiber da high-inganci ruwa rage wakili, shi yana da kyau kwarai Properties kamar matsananci-high matsawa ƙarfi, high tauri, high buga juriya karko da kuma karfi kai-warkarwa. iyawar micro-cracks. Ayyuka. Binciken fasaha na waje akan UHPC ya balaga sosai kuma an yi amfani da shi ga ayyuka masu amfani da yawa. Idan aka kwatanta da ƙasashen waje, bincike na cikin gida bai isa ba. Dong Jianmiao da sauransu sun yi nazarin haɗakar fiber ta hanyar ƙara nau'o'i daban-daban da adadin zaruruwa. Tsarin tasiri da dokar kankare; Chen Jing et al. yayi nazarin tasirin diamita na fiber karfe akan aikin UHPC ta hanyar zabar filayen karfe tare da diamita 4. UHPC tana da ƙaramin adadin aikace-aikacen injiniya a China, kuma har yanzu tana kan matakin bincike na ka'idar. Ayyukan UHPC Superiority ya zama ɗaya daga cikin hanyoyin bincike na ci gaban da aka samu, amma har yanzu akwai matsaloli da yawa da za a warware. Irin su manyan buƙatun don albarkatun ƙasa, farashi mai yawa, tsarin shirye-shirye masu rikitarwa, da dai sauransu, yana hana haɓaka fasahar samar da UHPC. Daga cikin su, ta yin amfani da tururi mai ƙarfi Maganin UHPC a babban zafin jiki na iya sa ya sami mafi girman kaddarorin inji da karko. Duk da haka, saboda ƙaƙƙarfan tsarin maganin tururi da manyan buƙatun don kayan aikin samarwa, aikace-aikacen kayan za a iya iyakance shi kawai zuwa yadudduka na farko, kuma ba za a iya aiwatar da ginin simintin gyare-gyare ba. Sabili da haka, bai dace ba don ɗaukar hanyar warkewar thermal a cikin ainihin ayyukan, kuma ya zama dole don gudanar da bincike mai zurfi akan maganin zafin jiki na al'ada UHPC.

Maganin zafin jiki na yau da kullun na UHPC yana cikin matakin bincike a kasar Sin, kuma rabonsa na ruwa-da-daure yana da rauni sosai, kuma yana da saurin bushewa a saman yayin ginin wurin. Domin inganta yanayin rashin ruwa yadda ya kamata, kayan da ke tushen siminti yawanci suna ƙara wasu kauri masu riƙe ruwa zuwa kayan. Wakilin sinadarai don hana rarrabuwa da zub da jini na kayan, haɓaka riƙewar ruwa da haɗin kai, haɓaka aikin gini, da haɓaka ingantaccen kayan injin siminti. Hydroxypropyl methyl cellulose ether (HPMC) a matsayin polymer Thickener, wanda zai iya yadda ya kamata rarraba da polymer gelled slurry da kayan a cikin sumunti na tushen kayan a ko'ina, da kuma free ruwa a cikin slurry zai zama daure ruwa, sabõda haka, ba sauki rasa daga. slurry da inganta aikin riƙewar ruwa na kankare .Domin rage tasirin ether cellulose a kan ruwa na UHPC, an zaɓi ƙananan ƙwayoyin cellulose ether don gwaji.

A taƙaice, don haɓaka aikin ginin bisa ga tabbatar da kaddarorin injina na maganin zafin jiki na yau da kullun na UHPC, wannan takarda tana nazarin tasirin ƙaramin ɗankowar abun ciki na ether cellulose akan yanayin zafi na al'ada dangane da kaddarorin sinadarai na ether cellulose. da tsarin aikinsa a cikin slurry UHPC. Tasirin ruwa, lokacin coagulation, ƙarfin matsawa, ƙarfin sassauƙa, ƙarfin juzu'i da ƙimar ƙarancin ƙarfi na UHPC don ƙayyade ƙimar da ta dace na ether cellulose.

1. Tsarin gwaji

1.1 Gwada albarkatun kasa da rabo mai gauraya

Abubuwan da ake amfani da su don wannan gwajin sune:

1) Siminti: P·O 52.5 simintin Portland na yau da kullun da aka samar a Liuzhou.

2) Tokar tashi: Tokar tashi da ake samarwa a Liuzhou.

3) Slag foda: S95 granulated fashewa makera slag foda samar a Liuzhou.

4) Silica fume: silica fume mai ɓoye-ɓoye, foda launin toka, abun ciki na SiO2≥92%, yanki na musamman 23 m²/g.

5) Yashi quartz: 20 ~ 40 raga (0.833 ~ 0.350 mm).

6) Mai rage ruwa: polycarboxylate mai rage ruwa, farin foda, rage yawan ruwa≥30%.

7) Latex foda: redispersible latex foda.

8) Fiber ether: hydroxypropyl methylcellulose METHOCEL da aka samar a Amurka, danko 400 MPa s.

9) Karfe fiber: madaidaiciyar jan karfe-plated microwire karfe fiber, diamitaφ shine 0.22 mm, tsawon shine 13 mm, ƙarfin ƙarfi shine 2 000 MPa.

Bayan mai yawa gwaji bincike a farkon mataki, za a iya ƙaddara cewa asali mix rabo na al'ada zazzabi curing matsananci-high yi kankare ne ciminti: tashi ash: Miner foda: silica fume: yashi: ruwa rage wakili: latex foda: ruwa = 860: 42: 83: 110: 980: 11: 2: 210, abun ciki na fiber na karfe shine 2%. Ƙara 0, 0.25%, 0.50%, 0.75%, 1.00% HPMC na cellulose ether (HPMC) abun ciki a kan wannan ƙayyadaddun mahaɗin mahaɗin Saita gwaje-gwajen kwatancen bi da bi.

1.2 Hanyar gwaji

Auna busassun albarkatun foda bisa ga hadawa rabo da sanya su a cikin HJW-60 guda-tsaye shaft tilasta kankare mahautsini. Zaki fara mixer har sai uniform din sai ki zuba ruwa ki gauraya na tsawon mintuna 3 sai ki kashe mixer din sai ki zuba zaren karfen da aka auna sannan a sake kunna mixer na tsawon mintuna 2. An yi shi cikin slurry UHPC.

Abubuwan da aka gwada sun haɗa da ruwa, lokacin saita lokaci, ƙarfin matsawa, ƙarfin sassauƙa, ƙarfin axial da ƙima na ƙarshe. An ƙaddara gwajin ruwa bisa ga JC/T986-2018 "Kayan Girbin Ciminti". Gwajin lokacin saitin shine gwargwadon GB/T 1346-2011 "Tsarin Cinikin Ruwa na Ciminti da Tsarin Gwajin Lokaci". An ƙaddara gwajin ƙarfin sassauƙa bisa ga GB/T50081-2002 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete". Gwajin ƙarfin ƙarfin ƙarfi, ƙarfin axial axial da Ƙarfin ƙimar ƙima an ƙaddara bisa ga DLT5150-2001 "Dokokin Gwajin Kankare na Hydraulic".

2. Sakamakon gwaji

2.1 Ruwa

Sakamakon gwajin ruwa yana nuna tasirin abun ciki na HPMC akan asarar ruwan UHPC akan lokaci. An lura daga yanayin gwajin cewa bayan slurry ba tare da cellulose ether yana motsawa ba a ko'ina, saman yana da wuyar rashin ruwa da ɓawon burodi, kuma ruwa ya ɓace da sauri. , kuma aiki ya lalace. Bayan ƙara ether cellulose, babu fata a saman, asarar ruwa a kan lokaci ya kasance ƙananan, kuma aikin ya kasance mai kyau. A cikin kewayon gwajin, mafi ƙarancin asarar ruwa shine 5 mm a cikin mintuna 60. Binciken bayanan gwajin ya nuna cewa, adadin Sl Sellar Sell ether yana da kadan tasiri a kan farkon ruwan uhpc, amma yana da babban tasiri ga asarar ruwa a kan lokaci. Lokacin da ba a ƙara ether cellulose ba, asarar ruwa na UHPC shine 15 mm; Tare da karuwa na HPMC, asarar ruwa na turmi yana raguwa; lokacin da adadin shine 0.75%, asarar ruwa na UHPC shine mafi ƙanƙanta tare da lokaci, wanda shine 5mm; bayan haka, tare da karuwa na HPMC, asarar ruwa na UHPC tare da lokaci Kusan bai canza ba.

BayanHPMCAn gauraye da UHPC, shi rinjayar da rheological Properties na UHPC daga bangarori biyu: daya shi ne cewa m micro-kumfa an kawo a cikin stirring tsari, wanda ya sa tara da kuma gardama ash da sauran kayan samar da wani "ball sakamako", wanda qara da workability A lokaci guda, babban adadin siminti na kayan aiki na iya nannade jimillar, don haka za'a iya "dakatar da" a ko'ina a cikin slurry, kuma yana iya motsawa cikin yardar kaina, an rage raguwa tsakanin aggregates, kuma yawan ruwa ya karu; na biyu shine haɓaka UHPC Ƙarfin haɗin gwiwa yana rage yawan ruwa. Tun da gwajin yana amfani da ƙananan danko HPMC, al'amari na farko daidai yake da al'amari na biyu, kuma ruwa na farko ba ya canzawa da yawa, amma ana iya rage asarar ruwa a kan lokaci. Dangane da nazarin sakamakon gwajin, ana iya sanin cewa ƙara adadin da ya dace na HPMC zuwa UHPC na iya haɓaka aikin ginin UHPC sosai.

2.2 Lokacin saita lokaci

Daga canjin yanayin saitin lokacin UHPC wanda adadin HPMC ya shafa, ana iya ganin cewa HPMC tana taka rawa a cikin UHPC. Mafi girman adadin shine, mafi bayyananniyar sakamako na jinkirtawa shine. Lokacin da adadin ya kasance 0.50%, lokacin saita turmi shine 55min. Idan aka kwatanta da ƙungiyar kulawa (minti 40), ya karu da 37.5%, kuma karuwar ba a bayyana ba. Lokacin da adadin ya kasance 1.00%, lokacin saita turmi shine 100 min, wanda shine 150% sama da na ƙungiyar kulawa (minti 40).

Siffofin tsarin kwayoyin halitta na ether cellulose suna shafar tasirin sa na jinkirtawa. Mahimmin tsarin kwayoyin halitta a cikin ether cellulose, wato, tsarin zoben anhydroglucose, na iya amsawa tare da ions alli don samar da mahaɗan ƙwayoyin ƙwayoyin ƙwayoyin calcium-calcium, rage lokacin shigar da siminti clinker hydration dauki. Ca (OH) 2, rage saurin siminti hydration dauki, don haka jinkirta saitin siminti.

2.3 Ƙarfin matsi

Daga dangantakar da ke tsakanin ƙarfin matsawa na samfuran UHPC a cikin kwanaki 7 da kwanaki 28 da abun ciki na HMPC, ana iya gani a fili cewa ƙari na HPMC a hankali yana ƙara raguwa a ƙarfin ƙarfin UHPC. 0.25% HPMC, ƙarfin matsawa na UHPC yana raguwa kaɗan, kuma ƙarfin ƙarfin ƙarfi shine 96%. Ƙara 0.50% HPMC ba shi da wani tasiri a fili akan ƙimar ƙarfin matsawa na UHPC. Ci gaba da ƙara HPMC tsakanin iyakokin amfani, UHPC's Ƙarfin matsawa ya ragu sosai. Lokacin da abun ciki na HPMC ya karu zuwa 1.00%, ƙimar ƙarfin matsawa ya ragu zuwa 66%, kuma asarar ƙarfin ya kasance mai tsanani. Dangane da bayanan bayanan, ya fi dacewa don ƙara 0.50% HPMC, kuma asarar ƙarfin matsawa kaɗan ne.

HPMC yana da wani tasiri mai hana iska. Bugu da kari na HPMC zai haifar da wani adadin microbubbles a cikin UHPC, wanda zai rage girma yawa na sabobin gauraye UHPC. Bayan slurry ya taurare, porosity zai ƙaru a hankali kuma ƙarancin zai ragu, musamman abun ciki na HPMC. Mafi girma. Bugu da ƙari, tare da karuwar adadin HPMC da aka gabatar, har yanzu akwai wasu nau'o'in polymers masu sassaucin ra'ayi a cikin pores na UHPC, wanda ba zai iya taka muhimmiyar rawa ba a cikin kyakkyawan rigidity da goyon bayan matsawa lokacin da aka matsa matrix na siminti. .Saboda haka, ƙari na HPMC yana rage ƙarfin matsawa na UHPC.

2.4 Ƙarfin sassauƙa

Daga dangantakar da ke tsakanin ƙarfin gyare-gyare na samfurori na UHPC a kwanakin 7 da kwanakin 28 da abun ciki na HMPC, ana iya ganin cewa canje-canjen sauye-sauye na ƙarfin ƙarfin da ƙarfin ƙarfin hali suna kama da juna, da kuma canjin ƙarfin da ke tsakanin 0 da 0.50% HMPC ba iri ɗaya bane. Yayin da ƙari na HPMC ya ci gaba, ƙarfin sassauƙa na samfuran UHPC ya ragu sosai.

Tasirin HPMC akan ƙarfin gyare-gyare na UHPC shine yafi a cikin bangarori uku: cellulose ether yana da retarding da kuma tasirin iska, wanda ya rage ƙarfin ƙarfin UHPC; kuma al'amari na uku shine polymer mai sassauƙa wanda aka samar ta hanyar ether cellulose, Rage tsattsauran ra'ayi yana rage raguwar ƙarfin ƙarfin samfurin kaɗan. Kasancewar waɗannan al'amura guda uku a lokaci guda yana rage ƙarfin matsi na samfurin UHPC kuma yana rage ƙarfin sassauƙa.

2.5 Ƙarfin ƙarfi na axial da ƙimar ƙimar ƙarshe

Dangantakar da ke tsakanin ƙarfin juzu'i na samfuran UHPC a 7 d da 28 d da abun ciki na HMPC. Tare da karuwar abun ciki na HPMC, ƙarfin juzu'i na samfuran UHPC ya fara canzawa kaɗan sannan ya ragu da sauri. Ƙarfin Ƙarfin Ƙarfin Ƙarfi ya nuna cewa lokacin da abun ciki na HPMC a cikin samfurin ya kai 0.50%, ƙimar ƙarfin ƙarfin axial na samfurin UHPC shine 12.2MPa, kuma ƙarfin ƙarfin ƙarfin shine 103%. Tare da ƙarin haɓaka abun ciki na HPMC na samfurin, axial Ƙarfin ƙarfin ƙarfi na tsakiya ya fara raguwa sosai. Lokacin da abun ciki na HPMC na samfurin ya kasance 0.75% da 1.00%, ƙimar ƙarfin ƙarfi shine 94% da 78%, bi da bi, waɗanda suka kasance ƙasa da ƙarfin ƙarfin axial na UHPC ba tare da HPMC ba.

Daga dangantakar da ke tsakanin ma'auni mai mahimmanci na samfurori na UHPC a cikin kwanaki 7 da kwanaki 28 da abun ciki na HMPC, ana iya ganin cewa mafi girman ƙimar ƙima ba su canzawa tare da karuwar ether cellulose a farkon, kuma lokacin da abun ciki na ciki ether cellulose ya kai 0.50% sannan ya fara raguwa da sauri.

Tasirin ƙarin adadin na HPMC akan ƙarfin ƙarfin axial da ƙima na ƙarshe na samfuran UHPC yana nuna yanayin kiyaye kusan canzawa sannan kuma raguwa. Babban dalilin shi ne cewa HPMC za a iya kai tsaye kafa tsakanin hydrated ciminti barbashi A Layer na waterproof polymer sealing film taka rawar sealing, sabõda haka, wani adadin ruwa da aka adana a UHPC, wanda ya samar da zama dole ruwa ga ci gaba da ci gaban hydration. na siminti, don haka inganta ƙarfin siminti. Bugu da ƙari na HPMC yana inganta haɗin kai na UHPC yana ba da slurry tare da sassauƙa, wanda ke sa UHPC ta dace sosai ga raguwa da lalata kayan tushe, kuma dan kadan inganta ƙarfin ƙarfin UHPC. Koyaya, lokacin da abun ciki na HPMC ya wuce ƙimar mahimmanci, iskar da aka shigar tana shafar ƙarfin samfurin. Abubuwan da ba su dace ba a hankali sun taka rawar gani, kuma ƙarfin juzu'i na axial da ƙimar ƙimar samfurin ta fara raguwa.

3. Kammalawa

1) HPMC na iya inganta aikin aiki na maganin zafin jiki na yau da kullun na UHPC, tsawaita lokacin coagulation da rage yawan asarar ruwa na UHPC da aka gauraya akan lokaci.

2) Bugu da ƙari na HPMC yana gabatar da wani adadin ƙananan kumfa yayin aikin motsa jiki na slurry. Idan adadin ya yi yawa, kumfa za su taru da yawa kuma su samar da kumfa masu girma. slurry yana da haɗin kai sosai, kuma kumfa ba za su iya cikawa da fashewa ba. Ƙunƙarar ƙaƙƙarfan UHPC suna raguwa; Bugu da ƙari, polymer mai sassauƙa da HPMC ke samarwa ba zai iya ba da tallafi mai ƙarfi ba lokacin da yake ƙarƙashin matsin lamba, kuma ƙarfin matsawa da sassauci yana raguwa sosai.

3) Bugu da ƙari na HPMC yana sa UHPC filastik da sassauƙa. Ƙarfin jujjuyawar axial da ƙimar ƙaƙƙarfan ƙima na samfuran UHPC da kyar ke canzawa tare da haɓaka abun ciki na HPMC, amma lokacin da abun ciki na HPMC ya zarce wani ƙima, Ƙarfin axial da ƙima na ƙarshe suna raguwa sosai.

4) Lokacin shirya al'ada zazzabi curing UHPC, da sashi na HPMC ya kamata a tsananin sarrafawa. Lokacin da adadin ya kasance 0.50%, dangantakar dake tsakanin aikin aiki da kaddarorin inji na maganin zafin jiki na al'ada UHPC na iya daidaitawa sosai.