Cov yeeb nkab steel yog siv rau kev xa cov kua dej thiab cov hmoov av, cov khoom siv hluav taws xob, kev tsim khoom thiab cov ntim khoom, nws yog cov khoom siv nyiaj txiag. Cov qauv siv hlau nrog steel truss, ncej thiab txhua yam kev txhawb nqa, tuaj yeem txo qhov hnyav, txuag 20 ~ 40% hlau, thiab tuaj yeem paub txog kev siv tshuab...
Nyeem ntxiv