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Enkosi ngokundwendwela i-scatter glassfiber cabron fiber contents .Usebenzisa uguqulelo lwebrawuza enenkxaso enyiniweyo yeCSS.Ngowona mava angcono, sicebisa ukuba usebenzise isikhangeli esihlaziyiweyo (okanye uvale iModi yokuThelela kwi-Internet Explorer).Ukongeza, ukuqinisekisa inkxaso eqhubekayo, sibonisa indawo ngaphandle kwezitayela kunye neJavaScript.
Ikhonkrithi yePolymer-reinforced (FRP) ithathwa njengendlela entsha kunye neyoqoqosho yokulungiswa kwesakhiwo.Kolu phononongo, izinto ezimbini eziqhelekileyo [carbon fibre reinforced polymer (CFRP) kunye neglass fiber reinforced polymer (GFRP)] zakhethwa ukuba zifunde isiphumo sokuqinisa ikhonkrithi kwiindawo ezirhabaxa.Ukuxhathisa kwekhonkrithi equlethe i-FRP kuhlaselo lwesulfate kunye nemijikelo enxulumene nomkhenkce wokunyibilikisa kuxoxiwe.I-electron microscopy yokufunda umphezulu kunye nokuthotywa kwangaphakathi kwekhonkrithi ngexesha lokhukuliseko oludibeneyo.Iqondo kunye nendlela ye-sodium sulfate corrosion yahlalutywa ngexabiso le-pH, i-SEM electron microscopy, kunye ne-EMF energy spectrum.Uvavanyo lwamandla oxinzelelo lwe-Axial lusetyenziselwe ukuvavanya ukuqiniswa kweekholamu zekhonkrithi ezinyanzelweyo ze-FRP, kunye nobudlelwane boxinzelelo loxinzelelo luye lwafunyanwa kwiindlela ezahlukeneyo zokugcinwa kwe-FRP kwindawo edityanisiweyo.Uhlalutyo lwemposiso lwenziwa ukulinganisa iziphumo zovavanyo kusetyenziswa imifuziselo emine ekhoyo.Lonke uqwalaselo lubonisa ukuba inkqubo yokuthotywa kwekhonkrithi ethintelweyo ye-FRP inzima kwaye iguquguqukayo phantsi koxinzelelo lwe-conjugate.I-sodium sulfate iqala ukwandisa amandla ekhonkrithi kwifom yayo eluhlaza.Nangona kunjalo, imijikelo elandelayo yokunyibilika komkhenkce inokwandisa ukuqhekeka kwekhonkrithi, kwaye i-sodium sulfate inciphisa ngakumbi amandla ekhonkrithi ngokukhuthaza ukuqhekeka.Imodeli yamanani echanekileyo icetywayo ukulinganisa ubudlelwane boxinzelelo loxinzelelo, olubalulekileyo ekuyileni nasekuphononongeni umjikelo wobomi bekhonkrithi ye-FRP.
Njengendlela entsha yokuqinisa ikhonkrithi ephandiweyo ukususela kwiminyaka yee-1970, i-FRP ineenzuzo zobunzima bokukhanya, amandla aphezulu, ukumelana nokugqwala, ukuxhathisa ukukhathala kunye nokwakhiwa okufanelekileyo1,2,3.Njengoko iindleko ziyancipha, ziya zixhaphaka kwizicelo zobunjineli ezifana ne-fiberglass (GFRP), i-carbon fiber (CFRP), i-basalt fiber (BFRP), kunye ne-aramid fiber (AFRP), eyona nto isetyenziswa kakhulu kwi-FRP yokuqinisa isakhiwo4, 5 Indlela yokugcinwa kwe-FRP ecetywayo inokuphucula ukusebenza kwekhonkrithi kwaye igweme ukuwa kwangaphambi kwexesha.Nangona kunjalo, iimeko ezahlukeneyo zangaphandle kubunjineli boomatshini zihlala zichaphazela ukuqina kwekhonkrithi elinganiselweyo ye-FRP, ebangela ukuba amandla ayo achaphazeleke.
Abaphandi abaliqela bafunde uxinzelelo kunye noxinzelelo lotshintsho kwikhonkrithi eneemilo ezahlukeneyo kunye nobukhulu obunqamlezayo.Yang et al.6 yafumanisa ukuba uxinzelelo lokugqibela kunye noxinzelelo lunxibelelene ngokufanelekileyo nokukhula kobukhulu bezicubu ze-fibrous.U-Wu et al.7 ufumene i-stress-strain curves kwi-concrete ye-FRP-constrained usebenzisa iintlobo ezahlukeneyo zefayibha ukuxela kwangaphambili ubunzima kunye nemithwalo.U-Lin et al.8 wafumanisa ukuba imodeli ye-FRP yoxinzelelo-uxinzelelo lwee-round, square, rectangular, kunye ne-elliptical bar nazo zihluke kakhulu, kwaye zaphuhlisa imodeli entsha yoxinzelelo olujoliswe kwi-design-oriented stress usebenzisa umlinganiselo wobubanzi kunye ne-radius yekona njengeparameters.U-Lam et al.9 waqaphela ukuba ukugqithiswa okungafaniyo kunye ne-curvature ye-FRP kubangele ukunyanzeliswa okuncinci kunye noxinzelelo kwi-FRP kuneemvavanyo ze-slab tensile.Ukongeza, izazinzulu ziye zafunda imiqobo kunye neendlela ezintsha zothintelo ngokweemfuno ezahlukeneyo zoyilo lwehlabathi lokwenyani.Wang et al.[I-10] yenza iimvavanyo zoxinzelelo lwe-axial ngokupheleleyo, ngokuyinxenye kunye nekhonkrithi engathintelwanga kwiindlela ezintathu ezilinganiselwe.Kuphuhliswe imodeli "yoxinzelelo loxinzelelo" kwaye i-coefficients yesiphumo sokunciphisa ikhonkrithi evalwe ngokuyinxenye inikezelwe.Wu et al.I-11 iphuhlise indlela yokuqikelela ukuxhomekeka koxinzelelo lwe-concrete ye-FRP-constrained ethatha ingqalelo kwimiphumo yobungakanani.U-Moran et al.12 uvavanye i-axial monotonic compression properties yekhonkrithi enyanzelweyo kunye ne-FRP helical strips kwaye ifumene i-curves yayo yoxinzelelo.Nangona kunjalo, olu phononongo lungentla luphonononga ngakumbi umahluko phakathi kwekhonkrithi evaleleke ngokuyinxenye kunye nekhonkrithi evalwe ngokupheleleyo.Indima yee-FRPs ezinciphisa ngokuyinxenye amacandelo ekhonkrithi ayikaphononongwa ngokweenkcukacha.
Ukongezelela, uphononongo luvavanye ukusebenza kwekhonkrithi ethintelweyo ye-FRP ngokubhekiselele kumandla oxinzelelo, ukuguqulwa koxinzelelo, i-modulus yokuqala ye-elasticity, kunye ne-strain-harding modulus phantsi kweemeko ezahlukeneyo.Tijani et al.I-13,14 yafumanisa ukuba ukulungiswa kwekhonkrithi ye-FRP-limited iyancipha ngokunyuka komonakalo kwiimvavanyo zokulungiswa kwe-FRP kwikhonkrithi eyonakalisiweyo.UMa et al.[I-15] yafunda umphumo womonakalo wokuqala kwiikholamu zekhonkrithi ezinyanzelweyo ze-FRP kwaye ziqwalasela ukuba umphumo wedigri yomonakalo kumandla obunzima wawungenamsebenzi, kodwa waba nefuthe elibalulekileyo kwi-deformations ye-lateral kunye ne-longitudinal.Nangona kunjalo, uCao et al.I-16 yaqaphela i-stress-strain curves kunye ne-stress-strain imvulophu ii-curves ze-FRP-contrained concrete ezichatshazelwa ngumonakalo wokuqala.Ukongeza kwizifundo zokungaphumeleli kwekhonkrithi yokuqala, ezinye izifundo ziye zaqhutywa malunga nokuqina kwe-concrete ye-FRP-incinci phantsi kweemeko zendalo ezingqongileyo.Ezi nzululwazi zifunde ukuthotywa kwekhonkrithi ethintelweyo ye-FRP phantsi kweemeko ezinzima kwaye zasebenzisa iindlela zokuvavanya umonakalo ukwenza iimodeli zokuthotywa ukuqikelela ubomi benkonzo.Xie et al.I-17 ibeke ikhonkrithi ye-FRP-contrained kwindawo ye-hydrothermal kwaye yafumanisa ukuba iimeko ze-hydrothermal zichaphazela kakhulu iipropathi ze-mechanical ze-FRP, ezibangele ukuhla kancinci kumandla oxinzelelo.Kwimeko-bume ye-acid-base, ujongano phakathi kweCFRP kunye nekhonkrithi iyawohloka.Njengoko ixesha lokuntywiliselwa lisanda, izinga lokukhululwa kwamandla okutshatyalaliswa komgangatho weCFRP liyancipha kakhulu, ekugqibeleni likhokelela ekutshatyalalisweni kweesampuli ezidibeneyo18,19,20.Ukongeza, ezinye izazinzulu ziye zafunda iziphumo zokukhenkceza kunye nokunyibilika kwi-concrete elinganiselweyo ye-FRP.U-Liu et al.21 baphawule ukuba irebar yeCFRP inokomelela kakuhle phantsi kwemijikelo yokunyibilika komkhenkce esekwe kwimodyuli eguqukayo, amandla oxinzelelo, kunye nomlinganiselo woxinzelelo.Ukongezelela, kucetywayo imodeli ehambelana nokuwohloka kweempawu zomatshini zekhonkrithi.Nangona kunjalo, u-Peng et al.22 ubala ubomi be-CFRP kunye ne-concrete adhesives usebenzisa ubushushu kunye nedatha yomjikelo we-freeze-thaw.UGuang et al.I-23 iqhube iimvavanyo ezikhawulezayo zokunyibilika kwekhonkrithi kwaye yandulula indlela yokuvavanya ukuxhathisa kweqabaka esekelwe kubunzima bomaleko owonakalisiweyo phantsi kokutyhileka komkhenkce.Yazdani et al.I-24 ifunde umphumo we-FRP layers ekungeneni kwe-chloride ion kwikhonkrithi.Iziphumo zibonisa ukuba umaleko we-FRP awunyangeki ngamachiza kwaye ufaka i-concrete yangaphakathi kwi-ion ye-chloride yangaphandle.U-Liu et al.25 ukulinganisa iimeko zokuvavanya i-peel ye-sulfate-corroded FRP ikhonkrithi, yenza imodeli ye-slip, kunye nokunciphisa kwangaphambili kwe-FRP-concrete interface.Wang et al.I-26 iseke imodeli yoxinzelelo lwe-stress-strain ye-FRP-constrained sulphate-eroded concrete ngokusebenzisa iimvavanyo zoxinzelelo lwe-uniaxial.UZhou et al.[27] wafunda umonakalo kwikhonkrithi engavalelwanga ebangelwa yimijikelo edityanisiweyo yokunyibilikisa yetyuwa kwaye ngokokuqala ngqa wasebenzisa umsebenzi wokuchaza indlela yokusilela.Ezi zifundo zenze inkqubela ebonakalayo ekuvavanyeni ukuqina kwe-concrete ye-FRP-limited.Nangona kunjalo, uninzi lwabaphandi bagxile kwimodeli yemithombo yeendaba erosive phantsi kwemeko enye engathandekiyo.Ikhonkrithi isoloko yonakaliswa ngenxa yokhukuliseko olunxulumeneyo olubangelwa ziimeko ezahlukeneyo zokusingqongileyo.Ezi meko zidibeneyo zokusingqongileyo zithoba kakhulu ukusebenza kwekhonkrithi ethintelweyo ye-FRP.
Imijikelo ye-sulfation kunye ne-freeze-nyibiliko yeendlela ezimbini ezibalulekileyo ezichaphazela ukuqina kwekhonkrithi.I-teknoloji yendawo ye-FRP inokuphucula iimpawu zekhonkrithi.Isetyenziswa ngokubanzi kubunjineli kunye nophando, kodwa okwangoku inemida yayo.Izifundo ezininzi zijolise ekuchaseni ikhonkrithi ye-FRP-ithintelwe kwi-corrosion ye-sulfate kwimimandla ebandayo.Inkqubo yokhukuliseko lwekhonkrithi evaliweyo ngokupheleleyo, evaliweyo kwaye evulekileyo nge-sodium sulfate kunye ne-freeze-thaw ifanele uphononongo olubanzi ngakumbi, ngakumbi indlela entsha evaliweyo echazwe kweli nqaku.Impembelelo yokuqinisa kwiikholamu zekhonkrithi nayo yaphononongwa ngokutshintshiselana ngomyalelo wokugcinwa kwe-FRP kunye nokukhukuliseka.Utshintsho lweMicrocosmic kunye ne-macroscopic kwisampulu ebangelwa kukukhukuliseka kwebhondi luphawulwe nge-electron microscope, uvavanyo lwe-pH, i-SEM electron microscope, uhlalutyo lwe-EMF yamandla kunye novavanyo lwe-uniaxial mechanical.Ukongeza, olu phononongo luxoxa ngemithetho elawula ubudlelwane boxinzelelo loxinzelelo olwenzeka kuvavanyo lwe-uniaxial mechanical.Uxinzelelo lomda olungqinisiswe ngokokulinga kunye nexabiso loxinzelelo lwaqinisekiswa luhlalutyo lwempazamo kusetyenziswa iimodeli ezine zoxinzelelo lomda okhoyo.Imodeli ecetywayo inokuqikelela ngokupheleleyo ubunzima bokugqibela kunye namandla ezinto eziphathekayo, eziluncedo kwixesha elizayo lokuqiniswa kweFRP.Okokugqibela, isebenza njengesiseko sombono we-FRP ikhonkrithi yokumelana netyuwa yetyuwa.
Olu phononongo luvavanya ukuwohloka kwe-concrete ye-FRP-limited kusetyenziswa ukubola kwesisombululo sesulfate kudityaniswe nemijikelo yokunyibilika komkhenkce.Utshintsho lweMicroscopic kunye ne-macroscopic olubangelwa kukhukuliseko lwekhonkrithi lubonakalisiwe kusetyenziswa i-electron microscopy yokuskena, uvavanyo lwe-pH, i-EDS ye-spectroscopy yamandla, kunye novavanyo lwe-uniaxial mechanical.Ukongezelela, iipropati zemishini kunye noxinzelelo-uxinzelelo lwe-concrete ye-FRP-inyanzeliso yekhonkrithi ephantsi kokhukuliseko olubophekileyo luphandwe kusetyenziswa iimvavanyo ze-axial compression.
I-FRP Confined Concrete iqulathe ikhonkrithi ekrwada, imathiriyeli yokusonga yangaphandle ye-FRP kunye ne-epoxy adhesive.Izinto ezimbini zokufakelwa kwangaphandle zikhethiweyo: i-CFRP kunye ne-GRP, iimpawu zezixhobo ziboniswa kwiThebhile 1. I-epoxy resins A kunye ne-B yayisetyenziswe njenge-adhesives (umxube wokuxuba 2: 1 ngevolumu).Irayisi.I-1 ibonisa iinkcukacha zokwakhiwa kwezinto zokuxuba eziphathekayo.Kumfanekiso 1a, i-Swan PO 42.5 i-samente yasePortland isetyenzisiwe.I-aggregates coarse ityunyuziwe ilitye le-basalt kunye nobubanzi be-5-10 kunye ne-10-19 mm, ngokulandelanayo, njengoko kuboniswe kumkhiwane.1b kunye c.Njengomzobo we-1g wasebenzisa isanti yomlambo yendalo kunye nemodyuli ye-fineness ye-2.3.Lungiselela isisombululo se-sodium sulfate kwi-granules ye-anhydrous sodium sulfate kunye nomlinganiselo othile wamanzi.
Ukubunjwa komxube wekhonkrithi: i-samente, b - i-aggregate 5-10 mm, c - i-aggregate 10-19 mm, d - isanti yomlambo.
Amandla oyilo lwekhonkrithi ngama-MPa angama-30, okubangela ukuhlaliswa kwekhonkrithi entsha ye-samente ye-40 ukuya kwi-100 mm.Umlinganiselo womxube wekhonkrithi uboniswe kwiThebhile 2, kwaye umlinganiselo we-coarse aggregate 5-10 mm kunye ne-10-20 mm ngu-3: 7.Umphumo wokusebenzisana kunye nokusingqongileyo uhlaziywe ngokuqala ngokulungiselela isisombululo se-10% se-NaSO4 kwaye emva koko ugalele isisombululo kwigumbi lomjikelo we-freeze-thaw.
Imixube yekhonkrithi yalungiswa kwi-0.5 m3 yokuxuba ngenkani kwaye yonke ibhetshi yekhonkrithi yayisetyenziselwa ukubeka iisampulu ezifunekayo.Okokuqala, izithako zekhonkrithi zilungiswa ngokweThebhile 2, kwaye isamente, isanti kunye ne-coarse aggregate zixutywe imizuzu emithathu.Emva koko usasaze ngokulinganayo amanzi kwaye ugxobhoze imizuzu emi-5.Emva koko, iisampulu zekhonkrithi zaphoswa kwi-cylindrical molds kwaye zihlanganiswe kwitafile eshukumayo (i-mold diameter 10 cm, ukuphakama kwe-20 cm).
Emva kokunyanga iintsuku ezingama-28, iisampulu zisongelwe ngezinto ze-FRP.Olu phononongo luxoxa ngeendlela ezintathu zeekholamu zekhonkrithi eziqinisiweyo, kubandakanywa zivalwe ngokupheleleyo, zithintelwe kancinci, kwaye zingathintelwanga.Iintlobo ezimbini, i-CFRP kunye ne-GFRP, zisetyenziselwa izinto ezilinganiselweyo.I-FRP ifakwe ngokupheleleyo igobolondo lekhonkrithi ye-FRP, i-20 cm ubude kunye ne-39 cm ubude.Umphezulu kunye nezantsi kwekhonkrithi eboshiweyo ye-FRP ayizange itywinwe nge-epoxy.Inkqubo yovavanyo lwe-semi-hermetic njengobuchwephesha obucetywayo mva nje bokungangeni moya ichazwa ngolu hlobo lulandelayo.
(2) Ukusebenzisa irula, dweba umgca kwi-concrete cylindrical surface ukuze unqume indawo ye-FRP strips, umgama phakathi kwemichilo yi-2.5 cm.Emva koko gubungela i-tape kwiindawo eziphathekayo apho i-FRP ingadingeki.
3Emva koko uncamathelise imicu yefiberglass kumphezulu wekhonkrithi kwaye ucinezele izithuba ukuze i-fiberglass ibambelele ngokupheleleyo kumphezulu wekhonkrithi kwaye ithintele amaqamza omoya.Ekugqibeleni, gcina i-FRP strips kwi-concrete surface ukusuka phezulu ukuya phezulu, ngokuhambelana namanqaku enziwe ngerula.
(4) Emva kwesiqingatha seyure, khangela ukuba ikhonkrithi yahlula kwi-FRP.Ukuba i-FRP iyatyibilika okanye iyaphuma, kufuneka ilungiswe ngokukhawuleza.Iisampulu ezibunjiweyo kufuneka zinyangwe kangangeentsuku ezisi-7 ukuqinisekisa ukomelela okunyangileyo.
5
Iziphumo phantsi kwemiqobo eyahlukeneyo ziboniswe kwifig.2. Umfanekiso we-2a ubonisa i-concrete ye-CFRP evaliweyo ngokupheleleyo, i-Figure 2b ibonisa i-concrete ye-semi-generalized ye-CFRP, i-Figure 2c ibonisa i-concrete ye-GFRP evaliweyo ngokupheleleyo, kunye ne-Figure 2d ibonisa ikhonkrithi ye-CFRP ene-semi-constrained.
Izimbo ezivalelweyo: (a) iCFRP evalelwe ngokupheleleyo;(b) i-semi-closed carbon fiber;(c) efakwe ngokupheleleyo kwi-fiberglass;(d) i-fiberglass enesiqingatha esivaliweyo.
Kukho iiparamitha ezine eziphambili ezenzelwe ukuphanda umphumo we-FRP izithintelo kunye nolandelelwano lokukhukuliseka kwindlela yokulawula ukutshatyalaliswa kweesilinda.Itheyibhile 3 ibonisa inani leesampuli zekholamu zekhonkrithi.Iisampulu zodidi ngalunye zibandakanya iisampulu zemo ezintathu ezifanayo ukugcina idatha ingaguquki.Intsingiselo yeesampulu ezintathu zahlalutywa kuzo zonke iziphumo zovavanyo kweli nqaku.
(1) Izinto ezingenamoya zihlelwa njenge-carbon fiber okanye i-fiberglass.Ukuthelekisa kwenziwa umphumo weentlobo ezimbini zemicu ekuqinisweni kwekhonkrithi.
(2) Iindlela zokulawula ikholamu yekhonkrithi zihlulwe zibe ziindidi ezintathu: zikhawulelwe ngokupheleleyo, zilinganiselwe kwaye azinamda.Ukumelana nokhukuliseko lweentsika zekhonkrithi ezivaleleke kancinci zithelekiswe nezinye iindidi ezimbini.
(3) Iimeko zokhukuliseko yimijikelo yokunyibilika komkhenkce kunye nesisombululo sesulfate, kwaye inani lemijikelo yokunyibilikisa yi-0, 50 kunye ne-100 ngokulandelelanayo.Isiphumo sokhukuliseko oludityanisiweyo kwiikholamu zekhonkrithi ezithintelweyo ze-FRP ziye zaphononongwa.
(4) Iziqwenga zovavanyo zahlulwe zibe ngamaqela amathathu.Iqela lokuqala yi-FRP yokusonga kwaye emva koko i-corrosion, iqela lesibini yi-corrosion kuqala kwaye emva koko isongelwe, kwaye iqela lesithathu yi-corrosion kuqala kwaye emva koko isonge kwaye i-corrosion.
Inkqubo yovavanyo isebenzisa umatshini wokuvavanya wendalo yonke, umatshini wokuvavanya ukuqina, iyunithi yomjikelo wokunyibilika komkhenkce (uhlobo lweCDR-Z), i-electron microscope, imitha ye-pH, igeyiji yoxinzelelo, isixhobo sokufuduswa, isibonakude se-electron se-SEM, kunye I-EDS ye-spectrum analyzer yamandla kolu phononongo.Isampuli yikholomu yekhonkrithi 10 cm ubude kunye no-20 cm ububanzi.Ikhonkrithi yaphiliswa kwisithuba seentsuku ezingama-28 emva kokugalelwa kunye nokudityaniswa, njengoko kubonisiwe kuMfanekiso 3a.Zonke iisampuli zaye zachithwa emva kokuphosa kwaye zagcinwa iintsuku ezingama-28 kwi-18-22 ° C kunye ne-95% yomswakama ohambelanayo, kwaye ezinye iisampuli zisongelwe nge-fiberglass.
Iindlela zokuvavanya: (a) izixhobo zokugcina ubushushu obungaguqukiyo kunye nokufuma;(b) umatshini wokunyibilikisa umkhenkce;(c) umatshini wovavanyo jikelele;(d) umvavanyi we-pH;(e) ukujonga ngemicroscope.
Umfuniselo wokunyibilikisa umkhenkce usebenzisa indlela yokukhenkcisa ilinyazi njengoko kubonisiwe kuMfanekiso 3b.Ngokutsho kwe-GB / T 50082-2009 "iMigangatho yokuGqiba kwiKhonkrithi eqhelekileyo", iisampulu zekhonkrithi zacwiliswa ngokupheleleyo kwi-10% isisombululo se-sodium sulfate kwi-15-20 ° C kwiintsuku ze-4 ngaphambi kokuqhwala kunye nokuqhaqha.Emva koko, uhlaselo lwe-sulfate luqala kwaye luphele ngaxeshanye kunye nomjikelo we-freeze-thaw.Ixesha lomjikelezo we-freeze-thaw yi-2 kwiiyure ze-4, kwaye ixesha lokutshatyalaliswa akufanele libe ngaphantsi kwe-1/4 yexesha lomjikelo.Ubushushu besampulu engundoqo kufuneka bugcinwe ngaphakathi koluhlu ukusuka (-18±2) ukuya (5±2) °С.Utshintsho ukusuka kumkhenkce ukuya kwi-defrosting akufanele kuthathe imizuzu engaphezu kweshumi.Iisampuli ezintathu ze-cylindrical ezifanayo zodidi ngalunye zisetyenziselwa ukufunda ukulahleka kwesisindo kunye nokuguqulwa kwe-pH yesisombululo phezu kwemijikelezo ye-freeze-thaw ye-25, njengoko kuboniswe kwi-Fig 3d.Emva kwayo yonke imijikelo ye-25 yokunyibilika komkhenkce, iisampulu zaye zasuswa kwaye umphezulu wacocwa ngaphambi kokumisela ubunzima bazo obutsha (Wd).Zonke iimvavanyo zenziwa ngokuphindwe kathathu kwiisampulu, kwaye amaxabiso aphakathi asetyenziselwa ukuxoxa ngeziphumo zovavanyo.Iifomula zokulahleka kobunzima kunye namandla esampuli zimiselwa ngolu hlobo lulandelayo:
Kwifomula, i-ΔWd yilahleko yobunzima (%) yesampulu emva kwe-25 yonke imijikelo yokunyibilika komkhenkce, i-W0 yi-avareji yobunzima besampulu yekhonkrithi phambi komjikelo wokunyibilika komkhenkce (kg), i-Wd yi-avareji yobunzima bekhonkrithi.ubunzima besampulu emva kwemijikelo engama-25 yokunyibilika komkhenkce (kg).
I-coefficient yokuthotywa kwamandla esampuli ibonakaliswe yi-Kd, kunye nefomula yokubala ngolu hlobo lulandelayo:
Kwifomula, ΔKd ngumyinge wokuphulukana namandla (%) kwisampulu emva kwe-50 yonke imijikelo yokunyibilika komkhenkce, f0 ngumndilili wamandla esampulu yekhonkrithi phambi komjikelo wokunyibilika komkhenkce (MPa), fd yi-avareji yamandla Isampulu yekhonkrithi yemijikelo engama-50 yokunyibilika komkhenkce (MPa).
Kwikhiwane.I-3c ibonisa umatshini wokuvavanya ocinezelayo kwiisampulu zekhonkrithi.Ngokuhambelana ne "Standard for Test Methods for the Physical and Mechanical Properties of Concrete" (GBT50081-2019), indlela yokuvavanya iikholomu zekhonkrithi zamandla oxinzelelo zichazwe.Izinga lokulayisha kuvavanyo lokunyanzeliswa kwe-0.5 MPa / s, kwaye ukulayisha okuqhubekayo kunye nokulandelelana kusetyenziswa kulo lonke uvavanyo.Ubudlelwane bokufuduswa komthwalo kwi-specimen nganye yabhalwa ngexesha lovavanyo lomatshini.Iigeyiji zoxinzelelo zifakwe kwiindawo zangaphandle zekhonkrithi kunye neengqimba ze-FRP zemizekelo yokulinganisa i-axial kunye ne-horizontal strains.Iseli yoxinzelelo isetyenziselwa uvavanyo lomatshini ukurekhoda utshintsho kwi-specimen strain ngexesha lovavanyo loxinzelelo.
Rhoqo kwimijikelo engama-25 yokunyibilika komkhenkce, isampulu yesisombululo sokunyibilikiswa komkhenkce yayikhutshwa yaza yafakwa kwisingxobo.Kwikhiwane.I-3d ibonisa uvavanyo lwe-pH yesisombululo sesampuli kwisitya.Ukuhlolwa kwe-Microscopic yendawo kunye necandelo lomnqamlezo wesampuli phantsi kweemeko ze-freeze-thaw kuboniswe kumfanekiso we-3d.Ubume bomphezulu weesampulu ezahlukeneyo emva kwe-50 kunye ne-100 ye-freeze-thaw cycle kwisisombululo se-sulfate yabonwa phantsi kwe-microscope.I-microscope isebenzisa i-400x yokwandisa.Xa uqwalasela umphezulu wesampulu, ukukhukuliseka komgangatho we-FRP kunye nomgangatho wangaphandle wekhonkrithi ubonwa ngokukodwa.Ukuqwalaselwa kwecandelo lomnqamlezo wesampuli ngokusisiseko kukhetha iimeko zokukhukuliseka kumgama we-5, 10 kunye ne-15 mm ukusuka kwinqanaba elingaphandle.Ukuqulunqwa kweemveliso ze-sulfate kunye nemijikelo ye-freeze-thaw kufuna uvavanyo olongezelelweyo.Ke ngoko, indawo elungisiweyo yeesampulu ezikhethiweyo ihlolwe kusetyenziswa i-electron microscope (SEM) exhotyiswe nge-energy dispersive spectrometer (EDS).
Jonga ngokubonakalayo umgangatho wesampulu nge-electronic microscope kwaye ukhethe i-400X yokukhulisa.Iqondo lomonakalo ongaphezulu kwikhonkrithi ye-GRP ebiyelweyo nengahlanganiyo phantsi komjikelo wokunyibilika komkhenkce kunye nokuvezwa kwiisulfates kuphezulu kakhulu, ngelixa kwikonkilethi evalwe ngokupheleleyo ayinanto.Udidi lokuqala lubhekisela kwisiganeko sokukhukuliseka kwekhonkrithi ehamba ngokukhululekileyo nge-sodium sulfate kunye nokusuka kwi-0 ukuya kwi-100 imijikelezo ye-freeze-thaw, njengoko kuboniswe kumfanekiso we-4a.Iisampulu zekhonkrithi ngaphandle kokuvezwa yiqabaka zinendawo egudileyo ngaphandle kweempawu ezibonakalayo.Emva kokhukuliseko lwe-50, ibloko yepulp phezu komhlaba ixobukile ngokuyinxenye, iveza igobolondo elimhlophe lepulp.Emva kokutshatyalaliswa kwe-100, iigobolondo zezisombululo zawa ngokupheleleyo ngexesha lokuhlola okubonakalayo kwendawo yekhonkrithi.Uqwalaselo lweMikroskopu lubonise ukuba umphezulu we-0 frize-nyibiliki yekhonkrithi yayigudileyo kwaye i-aggregate yomphezulu kunye nodaka zazikwinqwelomoya enye.Umphezulu ongalinganiyo, orhabaxa wabonwa kumphezulu wekhonkrithi okhukuliswe yimijikelo engama-50 yokunyibilika komkhenkce.Oku kunokuchazwa yinyaniso yokuba olunye udaka lutshatyalaliswa kwaye inani elincinci leekristale ezimhlophe zegranular zibambelela kumphezulu, owenziwe ngokukodwa ngokudibeneyo, udaka kunye neekristale ezimhlophe.Emva kwemijikelo ye-100 yokunyibilika komkhenkce, indawo enkulu yeekristale ezimhlophe yavela kumphezulu wekhonkrithi, ngelixa i-aggregate emnyama yavezwa kwindawo yangaphandle.Okwangoku, umphezulu wekhonkrithi ubukhulu becala buvezwe ngokudibeneyo kunye neekristale ezimhlophe.
I-morphology yomhlathi wekhonkrithi wokukhenkceza: (a) intsika yekhonkrithi engenamiqathango;(b) ikhonkrithi yekhabhoni ebiyelweyo ebiyelweyo;(c) ikhonkrithi evaleleke ngesiqingatha seGRP;(d) efakwe ngokupheleleyo kwikhonkrithi yeCFRP;(e) Ikhonkrithi yeGRP ebiyelwe ngokulinganayo.
Udidi lwesibini kukonakala kwesemi-hermetic CFRP kunye nekholamu zekhonkrithi yeGRP phantsi kwemijikelo yokukhenkcisa kunye nokuchanabeka kwiisulfates, njengoko kubonisiwe kwiFig. 4b, c.Ukuhlolwa okubonakalayo (ukwandiswa kwe-1x) kubonise ukuba i-powder emhlophe yenziwa ngokuthe ngcembe kumphezulu we-fibrous layer, eyawa ngokukhawuleza kunye nokunyuka kwenani lemijikelezo ye-freeze-thaw.Ukhukuliseko olungenamiqathango lomphezulu lwekhonkrithi ye-semi-hermetic ye-FRP luye lwacaca ngakumbi njengoko inani lemijikelo yokunyibilikisa lisanda.Into ebonakalayo "ye-bloating" (indawo evulekileyo yesisombululo sekholamu yekhonkrithi isekupheleni kokuwa).Nangona kunjalo, i-peeling phenomenon iphazamiseka ngokuyinxenye yi-carbon fiber coating ekufutshane).Ngaphantsi kwe-microscope, iifayili zekhabhoni zokwenziwa zivela njengemisonto emhlophe kwimvelaphi emnyama kwi-400x yokukhulisa.Ngenxa yobume obungqukuva beentsinga kunye nokuvezwa kukukhanya okungalinganiyo, zibonakala zimhlophe, kodwa i-carbon fiber bundles ngokwazo zimnyama.I-Fiberglass ekuqaleni ifana nentambo emhlophe, kodwa ekudibaneni ne-adhesive iba sobala kwaye imeko yekhonkrithi ngaphakathi kwefiberglass ibonakala ngokucacileyo.Ifiberglass imhlophe qhwa kwaye isibophelelo sityheli.Zombini zilula kakhulu ngombala, ngoko umbala weglue uya kufihla imisonto ye-fiberglass, unike inkangeleko iyonke i-tint etyheli.Iifiber zekhabhoni kunye neglasi zikhuselwe emonakalweni yi-epoxy resin yangaphandle.Njengoko inani lokuhlaselwa kwe-freeze-thaw liye landa, i-voids eninzi kunye neekristale ezimbalwa ezimhlophe zabonakala phezu komhlaba.Njengoko umjikelezo wokukhenkceza kwesulfate ukhula, i-binder iyancipha ngokuthe ngcembe, umbala ophuzi uyanyamalala kwaye imicu ibonakala.
Udidi lwesithathu kukuhlwa kwe-CFRP evaliweyo ngokupheleleyo kunye ne-GRP ikhonkrithi phantsi komjikelo we-freeze-thaw kunye nokuvezwa kwe-sulfates, njengoko kubonisiwe kwi-Fig. 4d, e.Kwakhona, iziphumo ezibonisiweyo zifana nezo zodidi lwesibini lwecandelo elinyanzelweyo lekholamu yekhonkrithi.
Thelekisa isenzeko esibonwe emva kokusebenzisa iindlela ezintathu zokuqulatha ezichazwe ngasentla.Izicubu ze-fibrous kwi-concrete ye-FRP e-insulated ngokupheleleyo zihlala zizinzile njengoko inani lemijikelezo yokunyibilika komkhenkce lisanda.Kwelinye icala, umaleko weringi wokuncamathelisa ubhityile kumphezulu.I-epoxy resins idla ngokusebenza kunye ne-hydrogen ion esebenzayo kwi-open-ring sulfuric acid kwaye kunzima ukusabela nge-sulfates28.Ngaloo ndlela, kunokuqwalaselwa ukuba ukhukuliseko lutshintsha ubukhulu becala iipropati ze-adhesive layer ngenxa ye-freeze-thaw cycles, ngaloo ndlela iguqula umphumo wokuqinisa we-FRP.Umphezulu wekhonkrithi we-FRP semi-hermetic concrete unesimo sokhukuliseko olufanayo nomphezulu wekonkrithi ongathintelwanga.Uluhlu lwayo lwe-FRP luhambelana noluhlu lwe-FRP lwekhonkrithi evaliweyo ngokupheleleyo, kwaye umonakalo awubonakali.Nangona kunjalo, kwikhonkrithi ye-GRP evaliweyo, ukuqhekeka okubanzi kokhukuliseko kwenzeka apho imicu yefiber idibana nekhonkrithi eveziweyo.Ukhukuliseko lwemiphezulu yekhonkrithi evezwayo iba mandundu ngakumbi njengoko inani lemijikelo yokunyibilikisa lisanda.
Ingaphakathi le-concrete ye-FRP evaliweyo ngokupheleleyo, i-semi-evaliweyo, kunye ne-concrete ye-FRP engathintelwanga ibonise ulwahlulo olubonakalayo xa luxhomekeke kwimijikelezo ye-freeze-thaw kunye nokuvezwa kwizisombululo ze-sulfate.Isampuli yasikwa ngokunqamlezayo kwaye icandelo lomnqamlezo labonwa kusetyenziswa i-electron microscope kwi-400x yokukhulisa.Kwikhiwane.I-5 ibonisa imifanekiso ye-microscopic kumgama we-5 mm, i-10 mm kunye ne-15 mm ukusuka kumda phakathi kwekhonkrithi kunye nodaka, ngokulandelanayo.Kuye kwaphawulwa ukuba xa isisombululo se-sodium sulfate sidibaniswa ne-freeze-thaw, umonakalo wekhonkrithi uphulwa ngokuthe ngcembe ukusuka phezulu ukuya ngaphakathi.Ngenxa yokuba iimeko zokhukuliseko lwangaphakathi lwe-CFRP kunye ne-GFRP-constrained concrete ziyafana, eli candelo alifanisi izinto ezimbini zokukhusela.
Ukuqwalaselwa kweMicroscopic yangaphakathi yecandelo lekhonkrithi yekholamu: (a) ilinganiselwe ngokupheleleyo yi-fiberglass;(b) zifakwe phakathi ngefiberglass;(c) ngokungenasiphelo.
Ukhukuliseko lwangaphakathi lwe-FRP oluvalwe ngokupheleleyo lwekhonkrithi lubonisiwe kwifig.5a.Ukuqhekeka kubonakala kwi-5 mm, umphezulu ulungile, akukho crystallization.Umphezulu ugudile, ngaphandle kweekristale, ubukhulu be-10 ukuya kwi-15 mm.Ukhukuliseko lwangaphakathi lwe-FRP semi-hermetic concrete lubonisiwe kwifig.5 B. Ukuqhekeka kunye neekristale ezimhlophe zibonakala kwi-5mm kunye ne-10mm, kwaye ubuso bubushelelezi kwi-15mm.Umzobo we-5c ubonisa amacandelo eekholamu zekhonkrithi ze-FRP apho iintanda zifunyenwe kwi-5, 10 kunye ne-15 mm.Iikristale ezimbalwa ezimhlophe kwiintanda ziye zaqhubeka zinqabile njengoko iintanda zisuka ngaphandle kwekhonkrithi ukuya ngaphakathi.Iikholamu zekhonkrithi ezingapheliyo zibonise ukhukuliseko oluninzi, lulandelwa yi-semi-constrained FRP ikholamu yekhonkrithi.I-sodium sulfate yaba nefuthe elincinane ngaphakathi kweesampulu zekhonkrithi ze-FRP ezivaleleke ngokupheleleyo ngaphezu kwemijikelo eyi-100 yokunyibilikisa.Oku kubonisa ukuba oyena nobangela wokhukuliseko lwekhonkrithi ye-FRP enyanzeleke ngokupheleleyo lukhukuliseko lomkhenkce onxulunyaniswa nokhukuliseko lwexesha elithile.Ukuqwalaselwa kwecandelo lomnqamlezo kubonise ukuba icandelo ngokukhawuleza ngaphambi kokukhenkcezwa kunye nokunyibilika lihamba kakuhle kwaye lingenazo ii-aggregates.Njengoko ikhonkrithi iqhwala kwaye inyibilika, ukuqhekeka kuyabonakala, kuyafana nakwi-aggregate, kwaye iikristale ezimhlophe zegranular zigqunywe kakhulu ngokuqhekeka.I-Studies27 ibonise ukuba xa ikhonkrithi ifakwe kwisisombululo se-sodium sulfate, i-sodium sulfate iya kungena kwikhonkrithi, ezinye zazo ziya kudlula njengeekristale ze-sodium sulfate, kwaye ezinye ziya kusabela ngesamente.Iikristale ze-sodium sulfate kunye neemveliso zokuphendula zibukeka njengeegranules ezimhlophe.
I-FRP inciphisa ngokupheleleyo iintanda zekhonkrithi kukhukuliseko oludibeneyo, kodwa icandelo ligudile ngaphandle kwekristallislization.Ngakolunye uhlangothi, i-FRP i-semi-closed kunye namacandelo ekhonkrithi angathinteliyo aphuhlise ukuqhekeka kwangaphakathi kunye ne-crystallization phantsi kokhukuliseko oludibeneyo.Ngokwenkcazo yomfanekiso kunye nezifundo zangaphambili29, inkqubo yokudilika edibeneyo yekhonkrithi ye-FRP engathintelwanga kunye ne-semi-stricted ihlukaniswe ngamanqanaba amabini.Inqanaba lokuqala lokuqhekeka kwekhonkrithi lihambelana nokwandiswa kunye nokunciphisa ngexesha le-freeze-thaw.Xa i-sulphate ingena kwikhonkrithi kwaye ibonakala, i-sulphate ehambelanayo igcwalisa iintanda ezenziwe ngokunciphisa kwi-freeze-thaw kunye ne-hydration reactions.Ngoko ke, i-sulfate inempembelelo ekhethekileyo yokukhusela kwikhonkrithi kwinqanaba lokuqala kwaye inokuphucula iimpawu zemishini yekhonkrithi kwinqanaba elithile.Isigaba sesibini sokuhlaselwa kwe-sulfate siyaqhubeka, singena kwiintanda okanye i-voids kwaye siphendule ngesamente ukwenza i-alum.Ngenxa yoko, ukuqhekeka kuyanda kwaye kubangela umonakalo.Ngeli xesha, ukwandiswa kunye nokuchasana kweempendulo ezihambelana nokukhenkcela kunye nokuncibilika kuya kwandisa umonakalo wangaphakathi kwikhonkrithi, okubangela ukunciphisa umthamo wokuthwala.
Kwikhiwane.I-6 ibonisa utshintsho lwe-pH yezisombululo zokufakelwa kwekhonkrithi kwiindlela ezintathu ezilinganiselweyo ezibekwe esweni emva kwe-0, 25, 50, 75, kunye ne-100 ye-freeze-thaw cycle.Iidaka zekhonkrithi ze-FRP ezingathintelwanga kunye nesiqingatha-ezivaliweyo zibonise ukunyuka kwe-pH ngokukhawuleza ukusuka kwi-0 ukuya kwi-25 imijikelezo yokuqhaqhazela.Amaxabiso abo e-pH anyuke ukusuka kwi-7.5 ukuya kwi-11.5 kunye ne-11.4, ngokulandelanayo.Njengoko inani lemijikelo yokunyibilika komkhenkce lisanda, ukunyuka kwe-pH kuye kwacotha kancinci emva kwe-25-100 yemijikelo yokunyibilika komkhenkce.Amaxabiso abo e-pH anyuke ukusuka kwi-11.5 kunye ne-11.4 ukuya kwi-12.4 kunye ne-11.84, ngokulandelanayo.Ngenxa yokuba ikhonkrithi ye-FRP ebophelelwe ngokupheleleyo igubungela umaleko we-FRP, kunzima ukuba isisombululo se-sodium sulfate singene.Ngexesha elifanayo, kunzima ukuba ukubunjwa kwe-samente kungene kwiisombululo zangaphandle.Ngaloo ndlela, i-pH inyuke ngokuthe ngcembe ukusuka kwi-7.5 ukuya kwi-8.0 phakathi kwe-0 kunye ne-100 yomjikelo wokunyibilikisa.Isizathu sokutshintsha kwe-pH sihlalutywa ngolu hlobo lulandelayo.I-silicate kwikhonkrithi idibanisa kunye ne-hydrogen ion emanzini ukwenza i-asilicic acid, kwaye i-OH eseleyo-iphakamisa i-pH yesisombululo esigcweleyo.Utshintsho kwi-pH luye lwacaca ngakumbi phakathi kwe-0-25 yemijikelo yokunyibilika komkhenkce kwaye ayivakali kakhulu phakathi kwe-25-100 yemijikelo yokunyibilika komkhenkce30.Nangona kunjalo, kwafunyaniswa apha ukuba i-pH iqhubekile ukunyuka emva kwe-25-100 ye-freeze-thaw cycle.Oku kunokuchazwa yinyaniso yokuba i-sodium sulfate ithatha iikhemikhali kunye nengaphakathi lekhonkrithi, iguqula i-pH yesisombululo.Uhlalutyo lokubunjwa kweekhemikhali lubonisa ukuba ikhonkrithi isabela nge-sodium sulfate ngale ndlela ilandelayo.
Iifomyula (3) kunye (4) zibonisa ukuba i-sodium sulfate kunye ne-calcium hydroxide kwifom ye-samente ye-gypsum (i-calcium sulfate), kunye ne-calcium sulfate iphinda iphendule nge-calcium metaaluminate kwi-samente ukuze yenze i-alum crystals.I-reaction (4) ihamba kunye nokuqulunqwa kwesiseko se-OH-, ekhokelela ekunyuseni kwe-pH.Kwakhona, ekubeni le mpendulo ibuyiselwa umva, i-pH inyuka ngexesha elithile kwaye itshintsha ngokukhawuleza.
Kwikhiwane.I-7a ibonisa ukulahlekelwa kwesisindo sekhonkrithi ye-GRP evaliweyo ngokupheleleyo, i-semi-enclosed, kunye ne-interlocked ngexesha lemijikelezo ye-freeze-thaw kwisisombululo se-sulfate.Utshintsho olucacileyo kakhulu ekulahlekeni kobunzima yikhonkrithi engathintelwanga.Ikhonkrithi engathintelwanga ilahlekelwe malunga ne-3.2% yobunzima bayo emva kokuhlaselwa kwe-frize-nying ye-50 kwaye malunga ne-3.85% emva kokuhlaselwa kwe-100 ye-frize-nying.Iziphumo zibonisa ukuba impembelelo yokhukuliseko oludityanisiweyo kumgangatho wekhonkrithi ehamba ngokukhululekileyo iyehla njengoko inani lemijikelo yokunyibilika komkhenkce lisanda.Nangona kunjalo, xa kujongwa umphezulu wesampulu, kwafunyaniswa ukuba ilahleko yodaka emva kwemijikelo ye-100 yokunyibilika komkhenkce yayinkulu kunasemva kwemijikelo engama-50 yokunyibilika komkhenkce.Ukudibanisa nezifundo kwicandelo langaphambili, kunokucingelwa ukuba ukungena kwe-sulfates kwikhonkrithi kukhokelela ekunciphiseni ukulahleka okukhulu.Okwangoku, i-alum eyenziwe ngaphakathi kunye ne-gypsum iphinda ibangele ukulahleka kwesisindo esicothayo, njengoko kuqikelelwe ngokulinganisa kweekhemikhali (3) kunye (4).
Ukutshintsha ubunzima: (a) ubudlelwane phakathi kokutshintsha kobunzima kunye nenani lemijikelo yokunyibilika komkhenkce;(b) ubudlelwane phakathi kokutshintsha kobunzima kunye nexabiso le-pH.
Utshintsho ekulahlekeni kobunzima be-FRP semi-hermetic ikhonkrithi kuqala kuncipha kwaye emva koko kwanda.Emva kwemijikelo engama-50 yokunyibilika komkhenkce, ilahleko enkulu yekhonkrithi ye-semi-hermetic fiberglass imalunga ne-1.3%.Ukulahlekelwa kwesisindo emva kwemijikelezo ye-100 yayingu-0.8%.Ngoko ke, kunokugqitywa ukuba i-sodium sulfate ingena kwikhonkrithi ekhululekile.Ukongeza, ukujongwa komphezulu wesiqwenga sovavanyo kukwabonise ukuba imicu yefiber inokumelana nodaka lodaka kwindawo evulekileyo, ngaloo ndlela inciphisa ukwehla kobunzima.
Utshintsho ekulahlekeni kobunzima bekhonkrithi ye-FRP evaliweyo ngokupheleleyo ihluke kwizinto ezimbini zokuqala.IMisa ayilahleki, kodwa yongeza.Emva kokhukuliseko lwama-50 lweqabaka, ubunzima bunyuke malunga ne-0.08%.Emva kwamaxesha e-100, ubunzima bayo bunyuke malunga ne-0.428%.Ekubeni ikhonkrithi igalelwe ngokupheleleyo, udaka oluphezu kwendawo yekhonkrithi aluyi kuphuma kwaye akunakwenzeka ukuba lubangele ukulahleka komgangatho.Ngakolunye uhlangothi, ukungena kwamanzi kunye ne-sulfates ukusuka kumxholo ophezulu kwindawo yangaphakathi yekhonkrithi ephantsi kunye nokuphucula umgangatho wekhonkrithi.
Uphononongo oluninzi luye lwaqhutywa ngaphambili kubudlelwane phakathi kwe-pH kunye nelahleko enkulu kwi-concrete ethintelweyo ye-FRP phantsi kweemeko zokhukuliseko.Uninzi lophando luxoxa ikakhulu ngobudlelwane phakathi kokulahleka kobunzima, i-elastic modulus kunye nokulahleka kwamandla.Kwikhiwane.I-7b ibonisa ubudlelwane phakathi kwekhonkrithi ye-pH kunye nelahleko enkulu phantsi kwemiqobo emithathu.Imodeli eqikelelwayo indululwa ukuqikelela ilahleko yobunzima obubambekayo kusetyenziswa iindlela ezintathu zokugcina kumaxabiso ahlukeneyo e-pH.Njengoko kunokubonwa kwi-Figure 7b, i-coefficient ye-Pearson iphezulu, ebonisa ukuba ngokwenene kukho ulungelelwaniso phakathi kwe-pH kunye nokulahleka okukhulu.Amaxabiso aphinda-phindwe ka-r kwikhonkrithi engathintelwanga, enesiqingatha, kunye nothintelo ngokupheleleyo yayiyi-0.86, 0.75, kunye ne-0.96, ngokulandelelanayo.Oku kubonisa ukuba utshintsho lwe-pH kunye nokuncipha kobunzima bekhonkrithi egqunyiweyo ngokupheleleyo inomgca phantsi kweemeko zombini zesulfate kunye ne-freeze-nyibiliki.Kwikhonkrithi engathintelwanga kunye ne-semi-hermetic FRP ikhonkrithi, i-pH iyanda ngokuthe ngcembe njengoko i-samente isabela ngesisombululo samanzi.Ngenxa yoko, umgangatho wekhonkrithi utshatyalaliswa ngokuthe ngcembe, nto leyo ekhokelela ekubeni ubunzima.Ngakolunye uhlangothi, i-pH yekhonkrithi evaliweyo ngokupheleleyo itshintsha kancinci kuba i-FRP layer inciphisa ukusabela kweekhemikhali zesamente kunye nesisombululo samanzi.Ngaloo ndlela, kwikhonkrithi evaliweyo ngokupheleleyo, akukho ukuguguleka komhlaba okubonakalayo, kodwa kuya kuzuza ubunzima ngenxa yokuhluthwa ngenxa yokufunxa izisombululo zesulfate.
Kwikhiwane.I-8 ibonisa iziphumo ze-SEM zokuskena iisampuli ezifakwe kwi-sodium sulfate freeze-thaw.I-electron microscopy ihlolisise iisampulu eziqokelelwe kwiibhloko ezithathwe kumaleko angaphandle eentsika zekhonkrithi.Umzobo 8a ngumfanekiso we-electron we-microscope yokuskena wekhonkrithi engavalwanga phambi kokhukuliseko.Kuphawulwe ukuba kukho imingxunya emininzi kumphezulu wesampulu, echaphazela amandla ekholamu yekhonkrithi ngokwayo ngaphambi kokunyibilika kweqabaka.Kwikhiwane.I-8b ibonisa umfanekiso we-electron microscope wesampulu yekhonkrithi ye-FRP egqunywe ngokupheleleyo emva kwe-100 yemijikelo yokunyibilika komkhenkce.Iintanda kwisampulu ngenxa yokukhenkceza kunye nokunyibilika kunokubonwa.Nangona kunjalo, umphezulu ugudileyo kwaye akukho zikristale kuwo.Ngoko ke, iintanda ezingazaliswanga zibonakala ngakumbi.Kwikhiwane.I-8c ibonisa isampuli yekhonkrithi ye-semi-hermetic ye-GRP emva kwemijikelo ye-100 yokhukuliseko lweqabaka.Kucacile ukuba iintanda zanda kwaye iinkozo zakha phakathi kweentanda.Amanye ala masuntswana ancamathela kwiintanda.Ukuskena kwe-SEM yesampuli yekholamu yekhonkrithi engathintelwanga iboniswe kuMzobo 8d, into ehambelana nokukhawulelana kwesiqingatha.Ukuqhubela phambili ukucacisa ukubunjwa kweengqungquthela, iinqununu kwiingqungquthela zandiswa ngakumbi kwaye zihlalutywe kusetyenziswa i-EDS spectroscopy.Amalungu afika kwiimilo ezintathu ezahlukeneyo.Ngokutsho kohlalutyo lwe-spectrum yamandla, uhlobo lokuqala, njengoko kuboniswe kwi-Figure 9a, i-crystal block block, ikakhulukazi iqulunqwe yi-O, S, Ca kunye nezinye izinto.Ngokudibanisa iifomyula zangaphambili (3) kunye (4), kunokumiselwa ukuba inxalenye ephambili yezinto eziphathekayo yi-gypsum (calcium sulfate).Owesibini uboniswe kuMfanekiso 9b;ngokuhambelana nohlalutyo lwe-spectrum yamandla, yinto e-acicular non-directional object, kwaye iinxalenye zayo eziphambili ziyi-O, Al, S kunye ne-Ca.Iiresiphi ezidityanisiweyo zibonisa ukuba imathiriyeli ibandakanya ikakhulu i-alum.Ibhloko yesithathu eboniswe kwi-Fig. 9c, ibhloko engaqhelekanga, enqunywe ngokuhlalutya kwe-spectrum yamandla, ngokuyinhloko equlethwe ngamacandelo O, Na kunye no-S. Kwavela ukuba ezi ziyi-crystals ze-sodium sulfate.Ukuskena i-electron microscopy kubonise ukuba ininzi ye-voids yazaliswa ngeekristale ze-sodium sulfate, njengoko kuboniswe kuMzobo 9c, kunye neemali ezincinci zegypsum kunye ne-alum.
Imifanekiso ye-electron emikroskopu yeesampulu phambi nasemva komhlwa: (a) vula ikhonkrithi phambi kokuhlwa;(b) emva kokubola, i-fiberglass ivalwe ngokupheleleyo;(c) emva kokutya kwekhonkrithi ebiyelweyo ye-GRP;(d) emva kokudleka kwekhonkrithi evulekileyo.
Uhlalutyo luvumela ukuba senze izigqibo ezilandelayo.Imifanekiso ye-electron microscope yeesampuli ezintathu zonke zaziyi-1k × kunye nokuqhekeka kunye neemveliso zokhukuliseko zifunyenwe kwaye zabonwa kwimifanekiso.Ikhonkrithi engathintelwanga inezona ntanda zibanzi kwaye iqulethe iinkozo ezininzi.Ikhonkrithi ye-semi-pressure ye-FRP ingaphantsi kwekhonkrithi engenaxinzelelo ngokobubanzi bokuqhekeka kunye nokubala kwamasuntswana.I-concrete ye-FRP evalwe ngokupheleleyo inobubanzi obuncinane bokuqhekeka kwaye akukho masuntswana emva kokhukuliseko lomkhenkce.Konke oku kubonisa ukuba i-concrete ye-FRP evalelwe ngokupheleleyo yeyona nto isengozini yokukhukuliseka kumkhenkce kunye nokunyibilika.Iinkqubo zemichiza ngaphakathi kweekholamu zekhonkrithi ezivaliweyo kunye nezivulekileyo ze-FRP zikhokelela ekubunjweni kwe-alum kunye ne-gypsum, kwaye ukungena kwe-sulfate kuchaphazela i-porosity.Nangona imijikelezo ye-freeze-thaw iyona nto ibangela ukuqhekeka kwekhonkrithi, i-sulfates kunye nemveliso yazo igcwalisa ezinye iintanda kunye neepores kwindawo yokuqala.Nangona kunjalo, njengoko isixa kunye nexesha lokhukuliseko lukhula, iintanda ziyaqhubeka zikhula kwaye umthamo we-alum owenziweyo uyanda, okubangela ukuqhekeka kwe-extrusion.Ekugqibeleni, i-freeze-thaw kunye ne-sulfate exposure iya kunciphisa amandla ekholomu.