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Simintin da aka ƙarfafa polymer (FRP) ana ɗaukarsa wata sabuwar hanya ce ta gyare-gyaren tsari.A cikin wannan binciken, an zaɓi abubuwa guda biyu na al'ada [carbon fiber ƙarfafa polymer (CFRP) da gilashin fiber ƙarfafa polymer (GFRP)] don nazarin tasirin ƙarfafawa na kankare a cikin yanayi mara kyau.An tattauna juriya na kankare mai ɗauke da FRP zuwa harin sulfate da kuma abubuwan daskarewa-narkewa.Microscope na lantarki don nazarin saman da lalatawar siminti na ciki a lokacin da zaizayar ƙasa.An yi nazarin digiri da tsarin lalata sodium sulfate ta ƙimar pH, microscopy electron SEM, da EMF makamashi bakan.An yi amfani da gwaje-gwajen ƙarfin ƙarfi na axial don kimanta ƙarfafa ginshiƙan ƙaƙƙarfan ginshiƙan FRP, kuma an sami alaƙar damuwa don hanyoyi daban-daban na riƙe FRP a cikin mahalli mai haɗe-haɗe.An gudanar da bincike na kuskure don daidaita sakamakon gwajin gwaji ta amfani da ƙira guda huɗu da ke akwai.Duk abubuwan da aka lura suna nuna cewa tsarin lalatawar simintin da aka ƙuntata FRP yana da rikitarwa kuma yana da ƙarfi a ƙarƙashin matsalolin haɗin gwiwa.Sodium sulfate da farko yana ƙara ƙarfin siminti a cikin ɗanyen sigar sa.Duk da haka, hawan daskarewa-narkewa na gaba zai iya tsananta fashewar kankare, kuma sodium sulfate yana ƙara rage ƙarfin simintin ta hanyar haɓaka fasa.An gabatar da ingantaccen ƙirar ƙididdigewa don kwaikwayi dangantakar danniya-danniya, wanda ke da mahimmanci don ƙira da kimanta yanayin rayuwar siminti mai takurawa FRP.
A matsayin sabuwar hanyar ƙarfafawa ta kankare da aka yi bincike tun cikin 1970s, FRP yana da fa'idodin nauyi mai nauyi, ƙarfin ƙarfi, juriya na lalata, juriya ga gajiya da ingantaccen gini1,2,3.Yayin da farashin ke raguwa, yana ƙara zama ruwan dare a cikin aikace-aikacen injiniya kamar fiberglass (GFRP), fiber carbon (CFRP), basalt fiber (BFRP), da fiber aramid (AFRP), waɗanda aka fi amfani da FRP don ƙarfafa tsarin4, 5 Hanyar riƙewar FRP na iya inganta aikin kankare da guje wa rushewar da wuri.Koyaya, wurare daban-daban na waje a cikin injiniyan injiniya galibi suna shafar dorewa na siminti mai iyaka FRP, yana haifar da lalacewa ga ƙarfinsa.
Masu bincike da yawa sun yi nazarin damuwa da sauye-sauye a cikin kankare tare da siffofi da girma dabam dabam.Yang et al.6 ya gano cewa babban damuwa da damuwa sun haɗu da kyau tare da girma a cikin kauri mai fibrous.Wu et al.7 sun sami lanƙwasa-danniya don kankare-ƙunƙunwar FRP ta amfani da nau'ikan fiber iri-iri don tsinkaya matuƙar damuwa da lodi.Lin et al.8 sun gano cewa FRP nau'ikan nau'ikan damuwa don zagaye, murabba'i, rectangular, da sandunan elliptical suma sun bambanta sosai, kuma sun ɓullo da sabon ƙirar ƙira-daidaitacce na damuwa ta hanyar amfani da rabo na nisa da radius na kusurwa azaman sigogi.Lam et al.9 ya lura cewa ba tare da haɗin kai ba da kuma karkatar da FRP ya haifar da ƙarancin karaya da damuwa a cikin FRP fiye da gwaje-gwajen tsalle-tsalle.Bugu da ƙari, masana kimiyya sun yi nazarin ƙananan ƙuntatawa da sababbin hanyoyin ƙuntatawa bisa ga bukatun ƙira na ainihi daban-daban.Wang et al.[10] ya yi gwaje-gwajen matsawa axial akan cikakken, juzu'i da simintin da ba a iyakance ba a cikin iyakantattun hanyoyi guda uku.An ƙirƙiri samfurin "danniya-danniya" kuma an ba da ƙididdiga na tasirin iyakance don simintin da aka rufe.Wu et al.11 sun ƙirƙiro wata hanya don tsinkayar dogaro da damuwa-nauyi na kankare-ƙunƙunwar FRP wanda ke la'akari da girman tasirin.Moran et al.12 sun kimanta kaddarorin matsawa na axial monotonic na ƙuntataccen kankare tare da filayen helical na FRP kuma sun sami lanƙwasa-danniya.Duk da haka, binciken da ke sama ya fi yin nazarin bambancin da ke tsakanin simintin da aka rufe da shi da cikakken simintin.Ba a yi nazari dalla-dalla game da rawar da FRPs ke takawa ba.
Bugu da ƙari, binciken ya kimanta aikin simintin da aka ƙuntata FRP dangane da ƙarfin matsawa, canjin yanayi, ma'auni na farko na elasticity, da kuma ƙarfin ƙarfin hali a ƙarƙashin yanayi daban-daban.Tijjani et al.13,14 sun gano cewa gyaran gyare-gyare na siminti mai iyaka FRP yana raguwa tare da karuwar lalacewa a cikin gwaje-gwajen gyaran FRP akan simintin da aka lalata da farko.Ma et al.[15] yayi nazarin tasirin lalacewa na farko akan ginshiƙan ginshiƙan FRP kuma ya yi la'akari da cewa tasirin lalacewa akan ƙarfin ƙwanƙwasa ba shi da kyau, amma yana da tasiri mai mahimmanci akan nakasar gefe da na tsaye.Duk da haka, Cao et al.16 an lura da lanƙwasa-danniya da ƙwanƙolin ambulaf ɗin damuwa na simintin ƙaƙƙarfan FRP wanda lalacewar farko ta shafa.Baya ga nazarce-nazarce a kan gazawar kankare na farko, an kuma gudanar da wasu nazarin kan dorewar siminti mai iyaka FRP a ƙarƙashin matsanancin yanayi na muhalli.Waɗannan masanan kimiyya sun yi nazarin lalacewar simintin da aka ƙuntata FRP a ƙarƙashin yanayi mai tsauri kuma sun yi amfani da dabarun tantance lalacewa don ƙirƙirar ƙira don tsinkayar rayuwar sabis.Xie et al.17 ya sanya simintin FRP-constrained a cikin yanayin hydrothermal kuma ya gano cewa yanayin hydrothermal yana tasiri sosai ga kayan aikin injiniya na FRP, wanda ya haifar da raguwa a hankali a cikin ƙarfin matsawa.A cikin yanayin tushen acid, haɗin gwiwa tsakanin CFRP da kankare yana lalacewa.Yayin da lokacin nutsewa ya karu, yawan sakin makamashi na lalatawar CFRP Layer yana raguwa sosai, wanda a ƙarshe ya haifar da lalata samfuran tsaka-tsaki18,19,20.Bugu da kari, wasu masana kimiyya sun kuma yi nazari kan illar daskarewa da narke a kan siminti mai iyaka FRP.Liu et al.21 ya lura cewa CFRP rebar yana da kyakkyawan dorewa a ƙarƙashin daskarewa-narkewar hawan keke wanda ya danganci modules mai ƙarfi, ƙarfin matsawa, da ma'aunin damuwa.Bugu da ƙari, an ba da shawarar samfurin da ke da alaƙa da lalacewar kayan aikin injiniya na kankare.Koyaya, Peng et al.22 sun ƙididdige tsawon rayuwar CFRP da mannen kankare ta amfani da yanayin zafin jiki da daskare bayanan sake zagayowar.Guang et al.23 sun gudanar da gwaje-gwajen daskare da sauri na kankare kuma sun ba da shawarar wata hanya don tantance juriyar sanyi dangane da kauri da ya lalace a ƙarƙashin daskare-narke.Yazdani et al.24 yayi nazarin tasirin FRP yadudduka akan shigar da ions chloride cikin kankare.Sakamakon ya nuna cewa Layer FRP yana da juriya ta sinadarai kuma yana keɓance simintin ciki daga ions na chloride na waje.Liu et al.25 da aka kwaikwayi yanayin gwajin kwasfa don simintin FRP mai lalata sulfate, ya ƙirƙira ƙirar zamewa, da kuma annabta lalatawar ƙirar FRP-concrete.Wang et al.26 ya kafa samfurin damuwa don FRP-ƙaddara sulfate-eroded kankare ta hanyar gwajin matsawa uniaxial.Zhou et al.[27] yayi nazarin lalacewar simintin da ba a rufe ba ta hanyar haɗuwa da daskare-narkewar hawan gishiri kuma a karon farko sun yi amfani da aikin dabaru don kwatanta tsarin gazawar.Waɗannan karatun sun sami ci gaba sosai wajen kimanta dorewar siminti mai iyaka FRP.Duk da haka, yawancin masu bincike sun mayar da hankali kan yin ƙirar kafofin watsa labaru masu lalata a ƙarƙashin yanayi mara kyau.Kankara sau da yawa yakan lalace saboda zaizayar da ke tattare da shi ta hanyar yanayi daban-daban na muhalli.Waɗannan haɗe-haɗen yanayin muhalli suna ƙasƙantar da aikin siminti mai ƙuntata FRP.
Sulfation da daskare-narke hawan keke su ne nau'o'i masu mahimmanci guda biyu na yau da kullun da ke shafar karko na kankare.Fasahar ganowa ta FRP na iya inganta kaddarorin siminti.Ana amfani da shi sosai a aikin injiniya da bincike, amma a halin yanzu yana da iyakokin sa.Yawancin karatu sun mayar da hankali kan juriya na ƙayyadaddun ƙuntatawa na FRP zuwa lalata sulfate a cikin yankuna masu sanyi.Tsarin yazawa na cikakken rufewa, Semi-rufe da buɗaɗɗen kankare ta sodium sulfate da daskare-narke ya cancanci ƙarin cikakken nazari, musamman sabuwar hanyar da aka rufe da aka bayyana a cikin wannan labarin.An kuma yi nazarin tasirin ƙarfafawa akan ginshiƙan kankare ta hanyar musayar tsari na riƙewar FRP da zaizayar ƙasa.Microcosmic da macroscopic canje-canje a cikin samfurin da ke haifar da yashwar haɗin gwiwa an kwatanta su ta hanyar microscope na lantarki, gwajin pH, microscope na SEM, nazarin bakan makamashi na EMF da gwajin injin uniaxial.Bugu da ƙari, wannan binciken ya tattauna dokokin da ke kula da dangantaka da damuwa da ke faruwa a gwajin injin uniaxial.Ƙididdiga da aka tabbatar da gwajin gwaji da ƙimar ƙima an inganta su ta hanyar bincike na kuskure ta amfani da ƙira guda huɗu da ke da iyaka-danniya.Samfurin da aka tsara zai iya yin tsinkaya dalla-dalla matuƙar wahala da ƙarfin kayan, wanda ke da amfani ga aikin ƙarfafa FRP na gaba.A ƙarshe, yana aiki azaman tushen ra'ayi don ra'ayin juriyar sanyi na FRP kankare.
Wannan binciken yana kimanta lalacewar siminti mai iyaka FRP ta amfani da lalata maganin sulfate a hade tare da daskare hawan keke.An nuna sauye-sauye na ƙananan ƙwararru da macroscopic da ke haifar da yashwar kankare ta amfani da sikanin microscopy na lantarki, gwajin pH, EDS makamashi spectroscopy, da gwajin injin uniaxial.Bugu da kari, an bincika kaddarorin injina da sauye-sauyen damuwa na simintin da aka takurawa FRP wanda aka yi amfani da shi tare da lalatawar da aka haɗa ta amfani da gwaje-gwajen matsawa axial.
Confined Concrete na FRP ya ƙunshi ɗanyen kankare, kayan naɗa na waje na FRP da mannen epoxy.An zaɓi kayan haɗin waje guda biyu: CFRP da GRP, ana nuna kaddarorin kayan a cikin Tebur 1. An yi amfani da resin Epoxy A da B a matsayin manne (rabo mai haɗawa 2: 1 ta ƙara).Shinkafa1 yana kwatanta cikakkun bayanai game da gina kayan haɗin gwiwar kankare.A cikin hoto na 1a, an yi amfani da simintin Swan PO 42.5.An murkushe manyan tarin dutsen basalt tare da diamita na 5-10 da 10-19 mm, bi da bi, kamar yadda aka nuna a cikin fig.1b da c.A matsayin mai filler mai kyau a cikin siffa 1g yayi amfani da yashi na kogin na halitta tare da module mai kyau na 2.3.Shirya bayani na sodium sulfate daga granules na anhydrous sodium sulfate da wani adadin ruwa.
Abun da ke cikin cakuda kankare: a - ciminti, b - jimlar 5-10 mm, c - jimlar 10-19 mm, d - yashi kogi.
Ƙarfin ƙira na siminti shine 30 MPa, wanda ke haifar da sabon simintin siminti na 40 zuwa 100 mm.An nuna ma'auni mai haɗaɗɗen kankare a cikin Tebura 2, kuma rabon babban adadin 5-10 mm da 10-20 mm shine 3: 7.An tsara tasirin hulɗa tare da yanayin ta hanyar shirya 10% NaSO4 bayani na farko sannan kuma zuba maganin a cikin ɗakin daskarewa-narke.
An shirya kayan haɗin gwal a cikin 0.5 m3 mai tilastawa mai tilastawa kuma an yi amfani da duk nau'in simintin don shimfiɗa samfuran da ake buƙata.Da farko dai, ana shirya simintin siminti bisa ga tebur na 2, sannan siminti, yashi da ɗimbin yawa ana haɗa su har na mintuna uku.Sannan a rarraba ruwan daidai gwargwado sannan a motsa na tsawon mintuna 5.Bayan haka, an jefa samfuran siminti a cikin gyare-gyare na cylindrical kuma an haɗa su a kan tebur mai girgiza (diamita na 10 cm, tsayi 20 cm).
Bayan warkewa na kwanaki 28, samfuran an nannade su da kayan FRP.Wannan binciken yayi magana akan hanyoyi guda uku don ƙarfafa ginshiƙai, ciki har da cikakken rufewa, ƙananan ƙuntatawa, da kuma marasa ƙuntatawa.Nau'i biyu, CFRP da GFRP, ana amfani da su don ƙayyadaddun kayan aiki.FRP Cikakken harsashi na kankare na FRP, tsayi 20 cm da tsayi 39 cm.Sama da kasan simintin da aka daure FRP ba a rufe su da epoxy ba.Tsarin gwajin Semi-hermetic azaman fasahar hana iska da aka gabatar kwanan nan an kwatanta shi kamar haka.
(2) Yin amfani da mai mulki, zana layi a kan simintin cylindrical na kankare don ƙayyade matsayi na sassan FRP, nisa tsakanin sassan shine 2.5 cm.Sa'an nan kuma kunsa tef ɗin a kusa da wuraren da ba a buƙatar FRP.
(3) Ana goge saman siminti da santsi da takarda yashi, an goge shi da ulun barasa, kuma an shafe shi da epoxy.Sa'an nan kuma da hannu da hannu tsaunin fiberglass a kan simintin da kuma danna gibin don fiberglass ɗin ya kasance cikakke manne da saman simintin kuma ya guje wa kumfa mai iska.A ƙarshe, manne ginshiƙan FRP akan saman kankare daga sama zuwa ƙasa, bisa ga alamun da aka yi da mai mulki.
(4) Bayan rabin sa'a, duba ko simintin ya rabu da FRP.Idan FRP yana zamewa ko mannewa, yakamata a gyara shi nan da nan.Dole ne a warke samfuran da aka ƙera na tsawon kwanaki 7 don tabbatar da ƙarfin warkewa.
(5) Bayan warkewa, yi amfani da wuka mai amfani don cire tef ɗin daga saman kankare, kuma a ƙarshe sami ginshiƙi na siminti-hermetic FRP.
Ana nuna sakamakon ƙarƙashin ƙuntatawa daban-daban a cikin fig.2. Hoto na 2a yana nuna cikakken simintin CFRP ɗin da aka rufe, Hoto na 2b yana nuna simintin CFRP ɗin da ba a taɓa gani ba, Hoto na 2c yana nuna simintin GFRP cikakke, kuma Hoto na 2d yana nuna simintin CFRP mai ƙarancin ƙarfi.
Salon ruɗewa: (a) CFRP cikakke;(b) fiber carbon da aka rufe;(c) gaba ɗaya an rufe shi a cikin fiberglass;(d) Fiberglass mai ruɗewa.
Akwai manyan sigogi guda huɗu waɗanda aka ƙera don bincika tasirin matsalolin FRP da jeri na yazawa akan aikin sarrafa zaizara na silinda.Shafin 3 yana nuna adadin samfuran ginshiƙi na kankare.Samfurori na kowane nau'i sun ƙunshi samfuran matsayi iri ɗaya guda uku don kiyaye daidaiton bayanai.An bincika ma'anar samfurori guda uku don duk sakamakon gwaji a cikin wannan labarin.
(1) Abun da ke da iska an rarraba shi azaman fiber carbon ko fiberglass.An kwatanta tasirin nau'ikan zaruruwa guda biyu akan ƙarfafa siminti.
(2) Hannun ƙunƙun ginshiƙi sun kasu kashi uku: cikakken iyaka, mara iyaka da mara iyaka.An kwatanta juriyar yazawar ginshiƙan simintin da aka rufe da wasu nau'ikan guda biyu.
(3) Yanayin yazawa shine hawan daskarewa-narke tare da maganin sulfate, kuma adadin daskare-narkewa shine sau 0, 50 da 100, bi da bi.An yi nazarin tasirin yazawar haɗe-haɗe akan ginshiƙan kankare FRP.
(4) An raba guntun gwajin zuwa rukuni uku.Rukunin farko shine FRP wraping sannan kuma lalata, rukuni na biyu kuma shine lalatawar farko sannan kuma a nannade, rukuni na uku kuma shine lalatawar farko sannan a nade sannan kuma lalata.
Hanyar gwaji ta yi amfani da injin gwaji na duniya, na'urar gwaji ta tensile, naúrar daskare-narke (nau'in CDR-Z), microscope na lantarki, mita pH, ma'aunin ma'auni, na'urar sauyawa, na'urar microscope na SEM, da kuma EDS mai nazarin bakan makamashi a cikin wannan binciken.Samfurin shine ginshiƙin kankare 10 cm tsayi kuma 20 cm a diamita.An warkar da simintin a cikin kwanaki 28 bayan zubawa da kuma haɗa shi, kamar yadda aka nuna a hoto na 3a.Dukkan samfuran an lalata su bayan yin simintin gyare-gyare kuma an adana su na tsawon kwanaki 28 a zazzabi na 18-22 ° C da 95% zafi, sannan an nannade wasu samfuran da fiberglass.
Hanyoyin gwaji: (a) kayan aiki don kiyaye yawan zafin jiki da zafi;(b) injin daskarewa-narke;(c) Injin gwaji na duniya;(d) gwajin pH;(e) Ƙwararren kallo.
Gwajin daskare-narke yana amfani da hanyar daskare walƙiya kamar yadda aka nuna a hoto na 3b.Dangane da GB/T 50082-2009 "Ka'idodin Dorewa don Kankare na Al'ada", samfuran kankare sun nutsar da su gaba ɗaya a cikin 10% sodium sulfate bayani a 15-20 ° C na kwanaki 4 kafin daskarewa da narke.Bayan haka, harin sulfate yana farawa kuma yana ƙare lokaci guda tare da sake zagayowar daskarewa.Lokacin daskarewa-narkewa shine sa'o'i 2 zuwa 4, kuma lokacin daskarewa bai kamata ya zama ƙasa da 1/4 na lokacin sake zagayowar ba.Ya kamata a kiyaye samfurin ainihin zafin jiki a cikin kewayon (-18± 2) zuwa (5± 2) °C.Canji daga daskararre zuwa defrosting bai kamata ya ɗauki fiye da minti goma ba.An yi amfani da samfurori iri ɗaya na cylindrical guda uku na kowane nau'i don nazarin asarar nauyi da canjin pH na maganin akan 25 daskare-narke hawan keke, kamar yadda aka nuna a cikin 3d.Bayan kowane zagayowar daskare-narke 25, an cire samfuran kuma an tsaftace saman kafin tantance sabon nauyinsu (Wd).An gudanar da duk gwaje-gwaje a cikin nau'i uku na samfurori, kuma an yi amfani da matsakaicin dabi'u don tattauna sakamakon gwajin.Abubuwan da aka ƙayyade don asarar taro da ƙarfin samfurin an ƙaddara su kamar haka:
A cikin dabara, ΔWd shine asarar nauyi (%) na samfurin bayan kowane 25 daskare-narke hawan keke, W0 shine matsakaicin nauyin samfurin kankare kafin sake zagayowar daskare (kg), Wd shine matsakaicin nauyin kankare.nauyin samfurin bayan 25 daskare-narke hawan keke (kg).
Ƙarfin lalata ƙima na samfurin yana da alamar Kd, kuma tsarin lissafin shine kamar haka:
A cikin dabarar, ΔKd shine ƙimar ƙarfin hasara (%) na samfurin bayan kowane 50 daskare-narke hawan keke, f0 shine matsakaicin ƙarfin samfurin kankare kafin sake zagayowar daskare (MPa), fd shine matsakaicin ƙarfin ƙarfin. da kankare samfurin ga 50 daskare-narke hawan keke (MPa).
A kan fig.3c yana nuna injin gwaji mai matsawa don samfuran kankare.Dangane da "Standard don Hanyoyin Gwaji don Kayan Jiki da Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Kayan Gida" (GBT50081-2019), an ayyana hanyar don gwada ginshiƙan kankare don ƙarfin matsawa.Matsakaicin lodi a cikin gwajin matsawa shine 0.5 MPa / s, kuma ana amfani da ci gaba da ɗaukar nauyi a duk tsawon gwajin.An yi rikodin alaƙar ƙaura-ƙaya don kowane samfurin yayin gwajin injina.An haɗe ma'auni zuwa saman saman simintin da FRP na samfuran don auna ma'aunin axial da a kwance.Ana amfani da tantanin halitta a gwajin injina don yin rikodin canji a cikin nau'in samfurin yayin gwajin matsawa.
Kowane 25 daskare-narke hawan keke, da samfurin maganin daskare-narke an cire da kuma sanya a cikin wani akwati.A kan fig.3d yana nuna gwajin pH na maganin samfurin a cikin akwati.Binciken ƙwanƙwasa na sararin samaniya da ɓangaren giciye na samfurin a ƙarƙashin yanayin daskarewa yana nunawa a cikin siffa 3d.Yanayin saman samfurori daban-daban bayan 50 da 100 daskare-narke hawan keke a cikin maganin sulfate an lura da su a ƙarƙashin na'urar hangen nesa.Microscope yana amfani da haɓaka 400x.Lokacin lura da saman samfurin, an fi lura da zaizayar FRP da kuma saman siminti na waje.Lura da sashin giciye na samfurin yana zaɓar yanayin lalacewa a nesa na 5, 10 da 15 mm daga Layer na waje.Samar da samfuran sulfate da daskare-narkewar hawan keke yana buƙatar ƙarin gwaji.Sabili da haka, an bincika gyare-gyaren saman samfuran da aka zaɓa ta amfani da na'urar duba microscope (SEM) sanye da na'urar watsawa ta makamashi (EDS).
Bincika da gani saman samfurin tare da microscope na lantarki kuma zaɓi haɓaka 400X.Matsayin lalacewar ƙasa a cikin simintin GRP ɗin da ba a rufe ba tare da haɗin gwiwa a ƙarƙashin daskarewar hawan keke da fallasa sulfates yana da girma sosai, yayin da keɓaɓɓen simintin da aka rufe ba shi da komai.Kashi na farko yana nufin faruwar yazawar simintin da ke gudana kyauta ta sodium sulfate da kuma daga 0 zuwa 100 daskare hawan keke, kamar yadda aka nuna a cikin siffa 4a.Samfurori masu ƙanƙara ba tare da bayyanar sanyi ba suna da ƙasa mai santsi ba tare da fasali na bayyane ba.Bayan yazawa 50, toshewar ɓangaren ɓangaren ɓangaren ɓangaren ɓangaren ɓangaren ɓangaren ɓangaren ɓangaren ɓangaren ya fito, yana fallasa farin harsashi na ɓangaren litattafan almara.Bayan yazawa 100, harsashi na maganin sun fadi gaba daya yayin binciken gani na saman simintin.Duban gani da ido ya nuna cewa saman simintin daskare-narke 0 yayi santsi kuma jimillar saman da turmi suna cikin jirgi ɗaya.An ga wani wuri mara daidaituwa, mai ƙanƙara a kan wani siminti da ya rusa da hawan daskare 50.Ana iya bayyana wannan ta gaskiyar cewa an lalata wasu daga cikin turmi kuma ƙaramin adadin fararen lu'ulu'u masu ƙwanƙwasa suna manne da saman, wanda galibi ya ƙunshi tara, turmi da fararen lu'ulu'u.Bayan 100 daskare-narke hawan keke, wani babban yanki na farin lu'ulu'u ya bayyana a saman simintin, yayin da duhu m taro aka fallasa zuwa waje yanayi.A halin yanzu, saman kankare galibi an fallasa jimillar da fararen lu'ulu'u.
Ilimin ilimin halittar jiki na ginshiƙin kankare mai daskare-narke: (a) ginshiƙin kankare mara iyaka;(b) Simintin da aka ƙulla da simintin carbon fiber mai ƙarfi;(c) GRP siminti mai rufewa;(d) siminti na CFRP cikakke;(e) GRP kankare da aka rufe.
Kashi na biyu shine lalata ginshiƙan ginshiƙan Semi-hermetic CFRP da GRP a ƙarƙashin daskararren hawan keke da fallasa sulfates, kamar yadda aka nuna a hoto. 4b, c.Binciken gani (1x magnification) ya nuna cewa wani farin foda a hankali ya samo asali a saman Layer na fibrous, wanda da sauri ya fadi tare da karuwa a yawan daskarewa-narkewa.Rushewar simintin FRP ɗin da ba a iyakance ba ya zama mafi bayyana yayin da adadin daskare-narkewar ke ƙaruwa.Abubuwan da ake iya gani na "ƙumburi" (budewar farfajiyar maganin ginshiƙi na kankare yana kan gab da rushewa).Duk da haka, abin da ya faru na peeling yana fuskantar wani bangare ta hanyar murfin fiber carbon da ke kusa).Karkashin na'urar gani da ido, filayen carbon roba na roba suna bayyana azaman farin zaren akan bangon baki a girman girman 400x.Saboda yanayin zagaye na zaruruwa da fallasa zuwa ga haske mara daidaituwa, suna bayyana fari, amma dauren fiber carbon da kansu baƙar fata ne.Fiberglass da farko fari ne kamar zaren zare, amma idan aka tuntuɓar abin da ake amfani da shi ya zama bayyananne kuma yanayin simintin da ke cikin fiberglass yana bayyane a fili.Fiberglass fari ne mai haske kuma abin ɗaure yana da launin rawaya.Dukansu suna da haske sosai a cikin launi, don haka launi na manne zai ɓoye igiyoyin fiberglass, yana ba da yanayin gaba ɗaya launin rawaya.Carbon da filayen gilashi ana kiyaye su daga lalacewa ta hanyar resin epoxy na waje.Yayin da yawan hare-haren daskare-narke ke ƙaruwa, ƙarin ɓoyayyiya da ƴan fararen lu'ulu'u sun zama bayyane a saman.Yayin da sake zagayowar sulfate na daskarewa yana ƙaruwa, mai ɗaure a hankali ya zama sirara, launin rawaya yana ɓacewa kuma zaruruwan suna gani.
Nau'i na uku shine lalatawar CFRP da simintin GRP da aka rufe a ƙarƙashin daskarewar hawan keke da fallasa ga sulfates, kamar yadda aka nuna a hoto. 4d, e.Bugu da ƙari, sakamakon da aka lura yana kama da na nau'in nau'i na biyu na ƙuntataccen ginshiƙi na kankare.
Kwatanta abubuwan da aka gani bayan amfani da hanyoyin ƙulla abubuwa uku da aka kwatanta a sama.Tsuntsayen fibrous a cikin simintin FRP ɗin da aka keɓe sun kasance barga yayin da adadin daskarewa-narkewa ke ƙaruwa.A gefe guda, ƙirar zobe mai mannewa ya fi bakin ciki a saman.Epoxy resins galibi suna amsawa tare da ions hydrogen masu aiki a cikin buɗaɗɗen zobe na sulfuric acid kuma da kyar suke amsawa da sulfates28.Don haka, ana iya la'akari da cewa zaizayar ƙasa takan canza kaddarorin mannen Layer ne sakamakon daskarewar hawan keke, ta haka yana canza tasirin ƙarfafawa na FRP.Simintin siminti na FRP Semi-hermetic kankare yana da al'amarin yazawa iri ɗaya kamar saman kankare mara iyaka.Layin FRP ɗin sa yayi daidai da FRP na simintin da aka rufe gabaɗaya, kuma lalacewar ba ta bayyana ba.Duk da haka, a cikin simintin GRP da aka rufe, ɓarkewar ɓarna yana faruwa inda filayen fiber ke haɗuwa da simintin da aka fallasa.Rushewar saman kankare da aka fallasa yana ƙara yin tsanani yayin da adadin daskarewa-narkewar ke ƙaruwa.
Abubuwan ciki na cikakkun rufaffiyar, rufa-rufa, da simintin FRP mara iyaka sun nuna bambance-bambance masu mahimmanci lokacin da aka daskare hawan keke da fallasa ga mafita na sulfate.An yanke samfurin a hankali kuma an lura da sashin giciye ta amfani da microscope na lantarki a girman 400x.A kan fig.5 yana nuna ƙananan hotuna a nesa na 5 mm, 10 mm da 15 mm daga iyaka tsakanin siminti da turmi, bi da bi.An lura cewa lokacin da aka haɗa maganin sodium sulfate tare da daskare-narke, lalacewar kankare ta ci gaba da rushewa daga saman zuwa ciki.Saboda yanayin zaizayar ciki na CFRP da simintin takurawa GFRP iri ɗaya ne, wannan sashe baya kwatanta kayan haɗin kai guda biyu.
Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwararren Ƙwaƙwalwa na Ƙaƙwalwa na Ƙaƙwalwa na Ƙaƙwalwa na Ƙaƙwalwa na Ƙaƙwalwa: (a) Ƙarƙashin Ƙarƙashin Ƙarƙashin Ƙarƙwara;(b) Semi-rufe tare da fiberglass;(c) marar iyaka.
An nuna yazawar ciki na FRP cikakken siminti mai rufewa a cikin fig.5a ba.Ana iya ganin fashe a 5 mm, saman yana da ɗan santsi, babu crystallization.Fuskar tana santsi, ba tare da lu'ulu'u ba, kauri 10 zuwa 15 mm.An nuna zaizayar ciki ta FRP Semi-hermetic kankare a cikin fig.5 B. Cracks da fararen lu'ulu'u suna bayyane a 5mm da 10mm, kuma saman yana da santsi a 15mm.Hoto na 5c yana nuna sassan ginshiƙan FRP na kankare inda aka sami fasa a 5, 10 da 15 mm.Wasu fararen lu'ulu'u a cikin tsagewar sun zama ƙasa kaɗan yayin da tsagewar ke motsawa daga waje na simintin zuwa ciki.ginshiƙan kankare marasa iyaka sun nuna mafi yawan yazawa, sai kuma ginshiƙan kankare na FRP masu matsakaicin ra'ayi.Sodium sulfate ba shi da ɗan tasiri a ciki na samfuran kankarewar FRP sama da 100 daskararren hawan keke.Wannan yana nuni da cewa babban dalilin yazawar simintin FRP mai cike da takura yana da alaƙa da daskarewar zaizayar ƙasa na ɗan lokaci.Lura da sashin giciye ya nuna cewa sashin nan da nan kafin daskarewa da narkewa yana da santsi kuma ba tare da tari ba.Yayin da simintin ya daskare kuma ya narke, ana iya ganin fashe, haka lamarin yake ga jimillar, kuma fararen lu'ulu'u na granular suna lulluɓe da fasa.Nazarin 27 ya nuna cewa idan aka sanya siminti a cikin maganin sodium sulfate, sodium sulfate zai shiga cikin simintin, wanda wasu za su yi hazo a matsayin crystals na sodium sulfate, wasu kuma za su amsa da siminti.Sodium sulfate lu'ulu'u da samfuran dauki suna kama da farin granules.
FRP gabaɗaya yana iyakance ɓangarorin kankare a cikin yashwar da ke haɗuwa da juna, amma sashin yana da santsi ba tare da yin crystallization ba.A gefe guda kuma, sassan siminti na FRP da ba a iyakance ba sun haɓaka fashewar ciki da crystallization a ƙarƙashin gurɓataccen zaizayar ƙasa.Dangane da bayanin hoton da binciken da ya gabata29, tsarin haɗin gwiwar zaizayar ƙasa na siminti na FRP ba tare da iyakancewa ba ya kasu kashi biyu.Mataki na farko na fashewar kankare yana da alaƙa da haɓakawa da raguwa yayin daskarewa-narke.Lokacin da sulphate ya shiga cikin simintin kuma ya zama bayyane, sulphate daidai yake yana cika tsagewar da aka haifar ta hanyar raguwa daga daskare-narke da halayen hydration.Sabili da haka, sulfate yana da tasirin kariya na musamman akan kankare a matakin farko kuma yana iya haɓaka kayan aikin siminti zuwa wani ɗan lokaci.Mataki na biyu na harin sulfate ya ci gaba, yana shiga tsagewa ko ɓoyayyiya da amsa tare da siminti don samar da alum.A sakamakon haka, tsage yana girma da girma kuma yana haifar da lalacewa.A wannan lokacin, haɓakar haɓakawa da haɓakar haɓakar da ke tattare da daskarewa da narkewa za su ƙara lalacewa ta ciki ga siminti, yana haifar da raguwar ƙarfin ɗaukar nauyi.
A kan fig.6 yana nuna canje-canjen pH na ƙayyadaddun ƙayyadaddun ƙayyadaddun hanyoyin guda uku waɗanda aka kula da su bayan 0, 25, 50, 75, da 100 daskare hawan keke.Ba a iyakance ba da rufaffiyar rufaffiyar FRP tubalin turmi sun nuna mafi saurin hawan pH daga 0 zuwa 25 na daskare hawan keke.Ma'aunin pH ya karu daga 7.5 zuwa 11.5 da 11.4, bi da bi.Yayin da adadin daskarewa-narkewar ke ƙaruwa, haɓakar pH a hankali ya ragu bayan 25-100 daskare hawan keke.Ma'aunin pH ya karu daga 11.5 da 11.4 zuwa 12.4 da 11.84, bi da bi.Saboda cikakken haɗin FRP kankare yana rufe Layer FRP, yana da wahala maganin sodium sulfate ya shiga.A lokaci guda, yana da wuyar simintin siminti don shiga cikin mafita na waje.Don haka, a hankali pH ya karu daga 7.5 zuwa 8.0 tsakanin 0 zuwa 100 na daskare hawan keke.An yi nazarin dalilin canjin pH kamar haka.Silicate a cikin kankare yana haɗuwa da ions hydrogen a cikin ruwa don samar da silicic acid, kuma ragowar OH- yana ɗaga pH na cikakken bayani.Canjin pH ya fi fitowa fili tsakanin 0-25 daskare-narkewa da ƙasan magana tsakanin 25-100 daskare-narke cycles30.Duk da haka, an gano a nan cewa pH ya ci gaba da karuwa bayan 25-100 daskare-narke hawan keke.Ana iya bayyana wannan ta gaskiyar cewa sodium sulfate yana amsawa da sinadarai tare da ciki na kankare, yana canza pH na maganin.Binciken abubuwan sinadaran ya nuna cewa kankare yana amsawa da sodium sulfate ta hanya mai zuwa.
Formulas (3) da (4) sun nuna cewa sodium sulfate da calcium hydroxide a cikin siminti suna samar da gypsum (calcium sulfate), kuma calcium sulfate ya kara amsawa da calcium metaaluminate a cikin siminti don samar da lu'ulu'u na alum.Reaction (4) yana tare da samuwar OH- na asali, wanda ke haifar da karuwa a cikin pH.Har ila yau, tun lokacin da wannan amsa yana iya juyawa, pH yana tashi a wani lokaci kuma yana canzawa a hankali.
A kan fig.7a yana nuna asarar nauyi na cikakkar rufaffiyar, rufa-rufa, da madaidaicin siminti na GRP yayin hawan daskare-narke a cikin maganin sulfate.Mafi bayyananne canji a cikin asarar taro shine siminti mara iyaka.Simintin da ba a iyakance shi ba ya yi asarar kusan kashi 3.2% na yawan sa bayan hare-haren daskare 50 da kuma kusan kashi 3.85% bayan harin daskare 100.Sakamakon ya nuna cewa tasirin zaizayar da ke tattare da shi akan ingancin simintin da ke gudana kyauta yana raguwa yayin da adadin daskarewar hawan keke ke ƙaruwa.Duk da haka, lokacin da aka lura da saman samfurin, an gano cewa asarar turmi bayan daskarewa-narkewa 100 ya fi bayan 50 daskare-narke.Haɗe da binciken da aka yi a sashin da ya gabata, ana iya ɗauka cewa shigar da sulfates cikin kankare yana haifar da raguwar asarar yawan jama'a.A halin yanzu, alum da gypsum da aka samar a ciki suma suna haifar da raguwar nauyi, kamar yadda ma'aunin sinadarai (3) da (4) suka annabta.
Canjin nauyi: (a) dangantaka tsakanin canjin nauyi da adadin daskare-narke;(b) dangantaka tsakanin taro canji da pH darajar.
Canjin asarar nauyi na FRP Semi-hermetic kankare na farko yana raguwa sannan yana ƙaruwa.Bayan 50 daskare-narke hawan keke, da taro asarar Semi-hermetic fiberglass kankare ne game da 1.3%.Rashin nauyi bayan hawan keke 100 shine 0.8%.Saboda haka, ana iya ƙarasa da cewa sodium sulfate yana shiga cikin kankare mai gudana kyauta.Bugu da kari, lura da saman na'urar gwajin kuma ya nuna cewa filayen fiber na iya tsayayya da bawon turmi a budadden wuri, ta yadda za a rage asarar nauyi.
Canjin asara mai yawa na cikaken simintin FRP ya bambanta da na farko biyu.Mass baya rasa, amma yana ƙarawa.Bayan narkewar sanyi-50, yawan ya karu da kusan 0.08%.Bayan sau 100, yawan sa ya karu da kusan 0.428%.Tun da an zubar da simintin gaba ɗaya, turmin da ke saman simintin ba zai tashi ba kuma ba zai iya haifar da asarar inganci ba.A gefe guda kuma, shigar da ruwa da sulfates daga saman babban abun ciki zuwa cikin ciki na ƙananan simintin yana inganta ingancin simintin.
An gudanar da bincike da yawa a baya kan alakar pH da asarar yawan jama'a a cikin ƙayyadaddun ƙayyadaddun ƙayyadaddun FRP a ƙarƙashin yanayi mara kyau.Yawancin bincike sun fi tattauna dangantakar dake tsakanin asarar yawan jama'a, na'urorin roba da kuma asarar ƙarfi.A kan fig.7b yana nuna alakar da ke tsakanin siminti pH da asarar jama'a a ƙarƙashin ƙuntatawa uku.An gabatar da samfurin tsinkaya don tsinkayar asarar da yawa ta amfani da hanyoyin riƙewa guda uku a ƙimar pH daban-daban.Kamar yadda ake iya gani a hoto na 7b, ƙimar Pearson yana da girma, yana nuna cewa lallai akwai alaƙa tsakanin pH da asarar taro.Ma'auni na r-squared don marasa iyaka, ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun, da cikakken ƙuntataccen kankare sun kasance 0.86, 0.75, da 0.96, bi da bi.Wannan yana nuna cewa canjin pH da asarar nauyi na simintin da aka rufe cikakke yana da ingantacciyar layi a ƙarƙashin duka sulfate da yanayin narke.A cikin simintin da ba a iyakance ba da kuma Semi-hermetic FRP kankare, pH a hankali yana ƙaruwa yayin da simintin ke amsawa tare da maganin ruwa.A sakamakon haka, da kankare surface an hankali lalacewa, wanda take kaiwa zuwa rashin nauyi.A gefe guda kuma, pH na simintin da aka rufe gabaɗaya yana canzawa kaɗan saboda Layer FRP yana rage jinkirin halayen siminti tare da maganin ruwa.Don haka, ga simintin da aka rufe gabaɗaya, babu zaizayar ƙasa da ake iya gani, amma zai sami nauyi saboda jikewa saboda shayar da maganin sulfate.
A kan fig.8 yana nuna sakamakon binciken SEM na samfurori da aka yi da sodium sulfate daskare-narke.Makarantun lantarki sun bincika samfuran da aka tattara daga tubalan da aka ɗauka daga saman saman ginshiƙai na waje.Hoto 8a Hoton microscope na lantarki ne na siminti da ba a rufe ba kafin yazawa.An lura cewa akwai ramuka da yawa a saman samfurin, wanda ke shafar ƙarfin ginshiƙi da kansa kafin sanyi-narke.A kan fig.8b yana nuna hoton microscope na lantarki na cikakken samfurin kankare na FRP bayan daskare-narkewa 100.Ana iya gano fashe a cikin samfurin saboda daskarewa da narkewa.Koyaya, saman yana da ɗan santsi kuma babu lu'ulu'u akan sa.Saboda haka, tsagewar da ba a cika ba sun fi bayyane.A kan fig.8c yana nuna samfurin Semi-hermetic GRP kankare bayan zagayowar zaizayar sanyi 100.A bayyane yake cewa raguwa ya fadada kuma hatsi sun samo asali a tsakanin tsagewar.Wasu daga cikin waɗannan barbashi suna haɗa kansu zuwa tsagewa.Ana nuna sikanin SEM na samfurin ginshiƙin kankare mara iyaka a cikin Hoto na 8d, al'amarin da ya yi daidai da ƙayyadaddun ƙuntatawa.Don ƙarin bayani game da abubuwan da ke tattare da ƙwayoyin cuta, ƙwayoyin da ke cikin ɓarna sun kara girma da kuma nazarin su ta amfani da EDS spectroscopy.Barbashi da gaske suna zuwa cikin sifofi daban-daban guda uku.Dangane da nazarin bakan makamashi, nau'in farko, kamar yadda aka nuna a hoto na 9a, shine kristal toshe na yau da kullun, wanda galibi ya ƙunshi O, S, Ca da sauran abubuwa.Ta hanyar haɗa hanyoyin da suka gabata (3) da (4), ana iya ƙayyade cewa babban abin da ke cikin kayan shine gypsum (calcium sulfate).An nuna na biyu a cikin Hoto na 9b;bisa ga binciken bakan makamashi, abu ne mai acicular wanda ba shi da jagora, kuma manyan abubuwan da ke tattare da shi sune O, Al, S da Ca.Haɗin girke-girke ya nuna cewa kayan sun ƙunshi galibi na alum.Toshe na uku da aka nuna a cikin siffa 9c, toshe ne wanda bai bi ka'ida ba, wanda aka ƙaddara ta hanyar nazarin bakan makamashi, galibi ya ƙunshi abubuwan O, Na da S. Ya juya cewa waɗannan galibi lu'ulu'u ne na sodium sulfate.Binciken microscopy na lantarki ya nuna cewa yawancin ɓoyayyun suna cike da lu'ulu'u na sodium sulfate, kamar yadda aka nuna a cikin hoto 9c, tare da ƙananan gypsum da alum.
Hotunan microscopic na lantarki na samfurori kafin da bayan lalata: (a) buɗaɗɗen kankare kafin lalata;(b) bayan lalata, an rufe fiberglass gaba daya;(c) bayan lalatawar simintin da aka rufe na GRP;(d) bayan lalata buɗaɗɗen kankare.
Binciken ya ba mu damar zana wannan ƙarshe.Hotunan microscope na lantarki na samfuran guda uku duk 1k × ne kuma an sami fasa da samfuran yazawa kuma an lura dasu a cikin hotunan.Simintin da ba a iyakance shi ba yana da faɗuwar faɗuwa kuma ya ƙunshi hatsi da yawa.FRP Semi-matsa lamba kankare yana ƙasa da kankare mara matsa lamba dangane da faɗuwar faɗuwa da ƙididdigar barbashi.Simintin FRP ɗin da aka rufe cikakke yana da mafi ƙarancin faɗin faɗuwa kuma babu barbashi bayan daskare-narkewar zaizayarwa.Duk wannan yana nuna cewa cikakken rufin FRP kankare shine mafi ƙarancin kamuwa da zaizayewa daga daskare da narke.Hanyoyin sinadarai a cikin ruɓaɓɓen rukunoni da buɗe ginshiƙan FRP suna haifar da samuwar alum da gypsum, kuma shigar sulfate yana shafar porosity.Yayin da hawan keken daskarewa ke haifar da tsagewar kankare, sulfates da kayayyakinsu na cika wasu tsage-tsafe da kuraje tun da farko.Duk da haka, yayin da adadin da lokacin yashwa ya karu, raguwa ya ci gaba da fadada kuma ƙarar alum ya karu, yana haifar da fashewar extrusion.A ƙarshe, daskare-narke da bayyanar sulfate zai rage ƙarfin ginshiƙi.