Ukuthuthuka okusha ekuqinisekisweni kwekhwalithi yama-pavements aphathekayo kunganikeza ulwazi olubalulekile mayelana nekhwalithi, ukuqina, nokuhambisana namakhodi edizayini ayingxube.
Ukwakhiwa kwendawo egandaywe ngokhonkolo kungabona izimo eziphuthumayo, futhi usonkontileka udinga ukuqinisekisa ikhwalithi nokuqina kukakhonkolo osakazwa endaweni. Lezi zenzakalo zihlanganisa ukuchayeka emvuleni ngesikhathi sokuthulula, ngemva kokufakwa kokufakwa kwenhlanganisela yokwelapha, ukushwabana kwepulasitiki kanye namahora okuqhekeka emahoreni ambalwa ngemva kokuthululwa, kanye nezinkinga zokuthumela imiyalezo nokuphulukisa ngokhonkolo. Noma ngabe izidingo zamandla nokunye ukuhlolwa kwezinto ezibonakalayo kuhlangatshezwana nazo, onjiniyela bangadinga ukususwa nokushintshwa kwezingxenye ezigandayiwe ngoba bakhathazekile ngokuthi izinto ezingaphakathi kwe-situ ziyahlangabezana yini nokucaciswa kwedizayini eyingxube.
Kulokhu, i-petrography nezinye izindlela zokuhlola ezihambisanayo (kodwa ezichwepheshile) zinganikeza ulwazi olubalulekile mayelana nekhwalithi nokuqina kwezingxube zikakhonkolo nokuthi ziyahlangabezana yini nezimfuneko zomsebenzi.
Umfanekiso 1. Izibonelo zama-micrographs e-fluorescence microscope yokunamathisela ukhonkolo ku-0.40 w/c (ikhona eliphezulu kwesokunxele) kanye no-0.60 w/c (ekhoneni eliphezulu kwesokudla). Isithombe esingezansi kwesokunxele sibonisa idivayisi yokulinganisa ukumelana nesilinda kakhonkolo. Isibalo esingezansi kwesokudla sibonisa ubudlelwano phakathi kokumelana nevolumu kanye ne-w/c. I-Chunyu Qiao kanye ne-DRP, i-Twin Company
Umthetho Ka-Abrama: “Amandla acindezelayo engxube kakhonkolo ahambisana ngokuphambene nesilinganiso sawo sikasimende wamanzi.”
UProfesa Duff Abrams waqala wachaza ukuhlobana phakathi kwesilinganiso samanzi nosimende (w/c) namandla acindezelayo ngo-1918 [1], futhi wenza lokho manje okubizwa ngokuthi umthetho ka-Abrama: “Amandla acindezelayo esilinganiso samanzi/usimende esiqinile.” Ngaphezu kokulawula amandla acindezelayo, isilinganiso sikasimende wamanzi (w/cm) manje sesithandwa ngoba sibona ukushintshwa kukasimende wasePortland ngezinto zokuhlanganisa zikasimende ezifana nomlotha wempukane ne-slag. Futhi iyipharamitha eyinhloko yokuqina kwekhonkrithi. Ucwaningo oluningi lubonise ukuthi izingxube zikakhonkolo ezino-w/cm ngaphansi kuno-~0.45 zihlala isikhathi eside ezindaweni ezinolaka, njengezindawo ezichayeke emijikelezweni yokuncibilika okuqandisiwe enosawoti we-deicing noma izindawo lapho kunokugcwala okuphezulu kwe-sulfate emhlabathini.
Ama-capillary pores ayingxenye yemvelo yodaka lukasimende. Zihlanganisa isikhala phakathi kwemikhiqizo ye-cement hydration kanye nezinhlayiya zikasimende ezingenamanzi ezake zagcwala amanzi. [2] Ama-capillary pores mahle kakhulu kunezimbotshana eziboshiwe noma eziboshiwe futhi akufanele kudidaniswe nazo. Lapho ama-capillary pores exhunyiwe, uketshezi oluvela endaweni yangaphandle lungahamba ngokunamathisela. Lesi simo sibizwa ngokuthi ukungena futhi kufanele kuncishiswe ukuze kuqinisekiswe ukuqina. I-microstructure yengxube eqinile kakhonkolo ukuthi ama-pores ahlukaniswe kunokuba axhumeke. Lokhu kwenzeka uma i-w/cm ingaphansi kuka-~0.45.
Nakuba kudume kanzima ukulinganisa ngokunembile i-w/cm yokhonkolo oqinile, indlela ethembekile inganikeza ithuluzi elibalulekile lokuqinisekisa ikhwalithi lokuphenya ukhonkolo owenziwe lukhuni. I-Fluorescence microscopy inikeza isisombululo. Isebenza kanjena.
I-Fluorescence microscopy iyindlela esebenzisa i-epoxy resin kanye nodayi be-fluorescent ukuze kukhanye imininingwane yezinto. Isetshenziswa kakhulu kwisayensi yezokwelapha, futhi inezinhlelo zokusebenza ezibalulekile kwisayensi yezinto. Ukusetshenziswa okuhlelekile kwalendlela kukhonkolo kwaqala cishe eminyakeni engama-40 edlule eDenmark [3]; yamiswa emazweni aseNordic ngo-1991 ngokulinganisa i-w/c yokhonkolo oqinile, futhi yabuyekezwa ngo-1999 [4].
Ukukala i-w/cm yezinto ezisekelwe kusimende (okungukuthi, ukhonkolo, udaka, ne-grouting), i-epoxy ye-fluorescent isetshenziselwa ukwenza ingxenye encane noma ibhulokhi likakhonkolo elinogqinsi olulinganiselwa kuma-microns angu-25 noma i-intshi engu-1/1000 (Umfanekiso 2). Inqubo ibandakanya Ingqikithi kakhonkolo noma isilinda sisikwa kube amabhulokhi kakhonkolo ayisicaba (abizwa ngokuthi izikhala) nendawo ecishe ibe ngu-25 x 50 mm (1 x 2 amayintshi). Okungenalutho kunamathiselwe kusilayidi sengilazi, sibekwe ekamelweni le-vacuum, futhi i-epoxy resin yethulwa ngaphansi kwe-vacuum. Njengoba i-w / cm ikhula, ukuxhumeka kanye nenani lama-pores lizokhula, ngakho-ke i-epoxy eyengeziwe izongena ku-paste. Sihlola ama-flakes ngaphansi kwesibonakhulu, sisebenzisa isethi yezihlungi ezikhethekile ukuze sijabulise odayi be-fluorescent ku-epoxy resin futhi sihlunge amasignali amaningi. Kulezi zithombe, izindawo ezimnyama zimelela izinhlayiya ezihlanganisiwe kanye nezinhlayiya zikasimende ezingenamanzi. I-porosity yalokhu kokubili i-0%. Umbuthano oluhlaza okhanyayo yi-porosity (hhayi i-porosity), futhi i-porosity ngokuyisisekelo i-100%. Esinye salezi zici “Into” eluhlaza okotshani inamabala (Umfanekiso 2). Njengoba i-w/cm kanye ne-capillary porosity kakhonkolo yanda, umbala oyingqayizivele oluhlaza wokunamathisela uba ngokukhanya futhi ugqame (bheka Umfanekiso 3).
Umfanekiso 2. I-Fluorescence micrograph yama-flakes ebonisa izinhlayiya ezihlanganisiwe, i-voids (v) nokunamathisela. Ububanzi benkambu evundlile buyi-~ 1.5 mm. I-Chunyu Qiao kanye ne-DRP, i-Twin Company
Umfanekiso 3. Ama-micrographs e-fluorescence ama-flakes abonisa ukuthi njengoba i-w/cm ikhula, ukunamathisela okuluhlaza kancane kancane kuya kukhanya. Lezi zingxube zinomoya futhi ziqukethe umlotha wezimpukane. I-Chunyu Qiao kanye ne-DRP, i-Twin Company
Ukuhlaziywa kwesithombe kuhilela ukukhipha idatha yobuningi ezithombeni. Isetshenziswa emikhakheni eminingi yesayensi eyahlukene, kusukela kusibonakhulu senzwa ekude. Iphikseli ngayinye esesithombeni sedijithali iba iphuzu ledatha. Le ndlela isivumela ukuthi sinamathisele izinombolo emazingeni ahlukene okukhanya okuluhlaza abonwa kulezi zithombe. Eminyakeni engu-20 edlule noma ngaphezulu, ngenguquko emandleni ekhompuyutha yedeskithophu kanye nokutholwa kwezithombe zedijithali, ukuhlaziya izithombe manje sekuyithuluzi elingokoqobo elingase lisetshenziswe ochwepheshe abaningi be-microscope (kuhlanganise nama-petrologists aphathekayo). Sivame ukusebenzisa ukuhlaziya isithombe ukuze silinganise i-capillary porosity ye-slurry. Ngokuhamba kwesikhathi, sithole ukuthi kukhona ukuhlobana okuqinile kwezibalo okuhlelekile phakathi kwe-w / cm kanye ne-capillary porosity, njengoba kuboniswe kumfanekiso olandelayo (Umfanekiso 4 no-Figure 5)).
Umfanekiso 4. Isibonelo sedatha etholwe kuma-fluorescence micrographs ezingxenye ezincane. Le grafu ihlela inani lamaphikseli kuleveli empunga enikeziwe ku-photomicrograph eyodwa. Iziqongo ezintathu zihambisana nama-aggregates (ijika eliwolintshi), unamathisele (indawo empunga), kanye ne-void (isiqongo esingagcwalisiwe kwesokudla kude). Ijika lokunamathisela livumela umuntu ukubala isilinganiso sosayizi wembotshana kanye nokuchezuka kwayo okujwayelekile. I-Chunyu Qiao kanye ne-DRP, i-Twining Company Umfanekiso 5. Le grafu ifinyeza uchungechunge lwezilinganiso ze-capillary ezimaphakathi ka-w/cm kanye nezikhawu zokuzethemba ezingu-95% engxubeni eyakhiwe usimende omsulwa, usimende we-fly ash, kanye ne-pozzolan binder yemvelo. I-Chunyu Qiao kanye ne-DRP, i-Twin Company
Ekuhlaziyeni kokugcina, ukuhlolwa okuthathu okuzimele kuyadingeka ukufakazela ukuthi ukhonkolo wasendaweni uhambisana nokucaciswa kwedizayini eyingxube. Ngokusemandleni akho, thola amasampula abalulekile ekubekweni ahlangabezana nayo yonke imibandela yokwamukela, kanye namasampuli asuka ekubekweni okuhlobene. Umongo ovela esakhiweni esamukelwe singasetshenziswa njengesampula yokulawula, futhi ungawusebenzisa njengesilinganiso sokuhlola ukuthobelana kwesakhiwo esifanele.
Ngomuzwa wethu, lapho onjiniyela abanamarekhodi bebona idatha etholwe kusuka kulokhu kuhlolwa, ngokuvamile bayakwamukela ukubekwa uma ezinye izici eziyinhloko zobunjiniyela (njengamandla acindezelayo) zifinyelelwa. Ngokunikeza izilinganiso zobuningi be-w/cm kanye nesici sokwakheka, singadlulela ngale kokuhlolwa okushiwo emisebenzini eminingi ukuze sifakazele ukuthi ingxube okukhulunywa ngayo inezici ezizohumushela ekubeni ukuqina okuhle.
U-David Rothstein, Ph.D., PG, FACI ungumthwebuli wezithombe omkhulu we-DRP, A Twining Company. Uneminyaka engaphezu kwengu-25 yesipiliyoni sochwepheshe bezilwane ezifuywayo futhi wazihlolela mathupha amasampula angaphezu kuka-10,000 avela kumaphrojekthi angaphezu kuka-2,000 emhlabeni jikelele. UDkt. Chunyu Qiao, usosayensi omkhulu we-DRP, i-Twining Company, isazi sokuma komhlaba kanye nososayensi wezinto ezibonakalayo onesipiliyoni seminyaka engaphezu kweshumi ku-cementing materials kanye nemikhiqizo yedwala engokwemvelo kanye negayiwe. Ubuchwepheshe bakhe buhlanganisa ukusetshenziswa kokuhlaziywa kwesithombe kanye ne-fluorescence microscopy ukuze kufundwe ukuqina kukakhonkolo, ngokugcizelela ngokukhethekile umonakalo odalwe usawoti we-deicing, ukusabela kwe-alkali-silicon, nokuhlaselwa kwamakhemikhali ezindaweni zokuhlanza amanzi angcolile.
Isikhathi sokuthumela: Sep-07-2021