I-asphalt lulwelo lwendalo olubonakala kakhulu olunomphezulu omnyama kwaye lunyibilika kwikhabhoni disulfide (ulwelo olubugolide-tyheli, olunuka kakubi). Zihlala zikhona ngendlela ye-asphalt okanye itela.
I-asphalt inokohlulwa ikakhulu ibe ziindidi ezintathu: i-tar ye-coal pitch, i-petroleum asphalt kunye ne-asphalt yendalo: phakathi kwazo, i-tar pitch yamalahle yimveliso yokupheka. I-asphalt ye-Petroleum yintsalela emva kokuchithwa kwe-oyile ekrwada. I-asphalt yendalo igcinwa phantsi komhlaba, kwaye ezinye zenza iidiphozithi zeminerali okanye ziqokelelane kumphezulu womhlaba.
Ibhitumene ekwimo ye asphalt ifunyanwa ngokucokisa ioyile ekrwada ngokucazululwa. Zineendawo zokubilisa kwi-oyile ekrwada kwaye zizinto ezinzima kwi-oyile ekrwada, ngoko ke ziya kufumaneka emazantsi eenqaba zokwahlulahlula.
I-asphalt ngendlela yetar ifunyenwe ngokuphatha izinto eziphilayo (uninzi lwamalahle) ngokusebenzisa i-carbonization.
I-asphalt isoloko isetyenziswa xa kusakhiwa, njengokulungisa iindlela. Iindlela ezigalelwe itela kunye negrabile zibizwa ngokuba ziindlela zeasphalt.