Cov kav dej tooj liab muaj kev nyab xeeb thiab txhim khu kev qha
Cov kav dej tooj liab sib xyaw ua ke qhov zoo ntawm cov kav hlau hlau thiab cov kav dej tsis yog hlau. Lawv nyuaj dua li cov kav dej yas thiab muaj lub zog siab ntawm cov hlau dav dav (lub zog ntawm cov kav dej txias txias yog sib npaug rau cov kav hlau steel nrog tib phab ntsa tuab); Lawv yooj yim khoov dua li cov hlau dav dav, muaj qhov zoo toughness thiab siab ductility, thiab muaj kev co zoo heev, cuam tshuam tsis kam thiab Frost heave kuj.
Cov kav dej tooj liab tuaj yeem tiv taus qhov txias txias thiab kub kub, nrog rau ntau yam kev siv los ntawm -196 degrees mus rau 250 degrees, thiab tuaj yeem hloov kho qhov kub thiab txias (-high temperature-low temperature-high temperature-). Qhov kev ua tau zoo yuav tsis txo qis vim kev siv mus ntev thiab kev hloov pauv kub, thiab yuav tsis tsim kev laus. Qhov no yog dhau qhov ncav cuag ntawm cov kav dej zoo tib yam.
Lub linear expansion coefficient ntawm cov kav hlau yog me me, uas yog 1/10 ntawm cov kav dej yas, thiab nws yog qaug zog-resistant. Thaum qhov kub thiab txias hloov, yuav tsis muaj ntau thermal expansion thiab contraction, uas yuav ua rau muaj kev ntxhov siab qaug zog tawg.
Cov yam ntxwv no ua rau cov kav dej tooj liab muaj txiaj ntsig zoo hauv cov chaw txias. Nyob rau hauv qhov chaw txias heev, qhov kub ntawm qhov sib txawv thaum sawv ntxov thiab yav tsaus ntuj yog qhov loj, thiab cov kab sib txuas ntawm cov kav dej zoo tib yam yog qhov loj thiab lub zog tsawg, uas yooj yim heev los tsim kev ntxhov siab qaug zog tawg los ntawm thermal expansion thiab contraction. Qee tus hais tias lawv tsis nkig ntawm -20 degrees, tab sis qhov tseeb lawv tsis tuaj yeem tiv taus kev ua haujlwm siab thiab muaj lub neej ua haujlwm luv luv, uas tsis muaj qhov tseem ceeb. Txawm hais tias kev ntsuas rwb thaiv tsev tuaj yeem raug coj los siv, nws yog ib qho tsim nyog yuav tsum tau ntsib qhov kub thiab txias thaum lub sijhawm thauj mus los, khaws cia thiab teeb tsa. Kev ua haujlwm ntawm cov raj tooj liab ntawm -183 degrees yog tib yam li ntawm chav tsev kub.
