Thaum lub sij hawm asphalt txoj kev tsim kho, ntxiv ib qho tsim nyog ntawm pob zeb cov tsiaj ua ke, txhim kho kev sib tsoo li asphalt, txuas ntxiv txoj kev txij nkawm kev voj voog, muaj zog txoj kev txij nkawm cov nqi.
Hauv cov teb muaj kev ua si, nws yog dav siv nyob rau hauv hluav taws xob muaj zog, petrochemical thiab lwm yam kev muaj teb. Cov khoom lag luam tsim nyog rau txheej txheem tswj qhov kub thiab kev tiv thaiv hluav taws xob, cov kav dej xws li cov khoom siv thiab cov kav dej sov, cov tshuaj kub, ncu, ncu thiab lwm yam khoom siv. Nws tseem muaj lub suab zoo nqus tau, cov suab nrov txo thiab tiv thaiv kev tiv thaiv hluav taws.
Hauv kev tsim kho, pob zeb tsiaj yog siv dav hauv cov ru tsev, cov chaw ua haujlwm hauv lub zog, cov khoom nqus dej, thiab nqus cov hluav taws xob, cov suab nrov txo, thiab hws.
