Yuav ua li cas txog kev ua tau zoo ntawm choj lawj ua los ntawm fiberglass reinforced polymer (GFRP)?
Nyob rau hauv kev nyab xeeb hnyav ntawm Minnesota, Tebchaws Asmeskas, cov khoom siv tsis yog xim hlau siv los txhawb cov pob zeb ua vaj tse muaj peev xwm tswj tau tus choj kom ruaj khov thiab kev lag luam. Cov kev tshawb fawb ua ntej tau pom tias cov choj decks tsim nrogfiberglassReinforced Polymer (GFRP) ua tau zoo nrog cov khoom siv ua ke.
Corrosion ntawm embedded steel bars nyob rau hauv qhob yog lub ntsiab ua rau choj lawj degradation. Kev puas tsuaj tshwm sim thaum ya raws thiab chloride los ntawm txoj kev ntsev nkag mus rau hauv tus choj superstructure thiab corrode cov hlau. Thaum lub caij ntuj no hnyav nyob rau sab qaum teb-sab qaum teb ntawm lub tebchaws United States, cycles ntawm khov thiab thawing amplify cov nyhuv no, ua rau cov pob zeb tawg, ntxiv exposing embedded rebar.
GFRP steel bar yog ib qho uas tsis yog-hlau lwm txoj rau ib txwm steel bar, uas tsis oxidize los yog xeb thiab muaj zog corrosion kuj. Hauv qee thaj chaw ntawm Canada, GFRP tau siv los ua kev txhawb nqa lub lawj, tab sis nws siv hauv Tebchaws Meskas yog txwv. Cov kev tshawb fawb yav dhau los ntawm Minnesota thawj tus choj siv qhov kev txhawb nqa no pom tau tias GFRP tau tiv taus corrosion ntau dua li cov pa rebar thiab tsis muaj teeb meem ntawm cov qauv.
Hauv xyoo 2018, Tebchaws Asmeskas tau tsim ib khub ntawm ib sab ntawm tus choj ntawm Lub Cev 169, ib qho ntxiv nrog GFRP lawj thiab lwm qhov nrog cov pa epoxy-coated steel. Qhov kev tsim kho no muab lub sijhawm tshwj xeeb los sib piv qhov kev ua tau zoo ntawm ob hom kev txhawb nqa, vim tus choj raug cuam tshuam rau tib qho kev ntxhov siab ib puag ncig thiab dhau mus rau cov xwm txheej zoo sib xws. Qhov no yog lub sijhawm zoo los sib piv cov choj txuas ncaj qha nrog epoxy txheej. Cov kev ntxhov siab, hom, thiab deflections ntawm txhua tus choj lawj yog qhov zoo sib xws. Thaum kev siv GFRP rebar ntawm ob lub choj decks tau mus txog li plaub xyoos, nws tseem ntxov dhau rau Lub Tsev Haujlwm Saib Xyuas Kev Thauj Khoom los txiav txim siab txog kev siv cov khoom tshiab no, vim tias lub neej tsim ntawm choj feem ntau yog 75 xyoo. Cov ntaub ntawv ntau ntxiv ntawm cov khoom ntawm fiberglass steel yuav muab rau xyoo tom ntej, thiab cov koom haum cuam tshuam yuav txuas ntxiv tshawb xyuas nws cov kev siv.
