Asphalt yog cov kua roj uas muaj paug nrog cov npoo av uas muaj ntxhiab tsw zoo nkauj thiab yog soluble hauv carbon disulfide (ua kua kub-daj, ua kua daj). Lawv feem ntau muaj nyob rau hauv daim ntawv asphalt lossis tar.

Asphalt tuaj yeem muab faib ua peb hom: pateralum asphalt thiab ntuj asphalt: ntawm lawv, thee tar suab yog ib-khoom ntawm coking. Petroleum asphalt yog cov seem tom qab distillation ntawm cov roj crudill. Ntuj asphalt yog khaws cia hauv av, thiab qee qhov ua tiav ntxhia tso nyiaj los yog ua rau saum npoo ntawm lub ntiaj teb crust.
Bitumen nyob rau hauv daim ntawv ntawm asphalt yog tau los ntawm kev ua kom muaj roj crude los ntawm kev frectegation. Lawv muaj cov ntsiab lus npau taws hauv cov roj crude thiab yog cov tshuaj hnyav hauv cov roj crude, yog li lawv yuav pom nyob hauv qab ntawm fractions yees.
Asphalt nyob rau hauv daim ntawv ntawm tar yog tau los ntawm kev kho cov organic teeb meem (feem ntau thee) los ntawm kev siv hluav taws xob.
Asphalt feem ntau siv nyob rau hauv kev tsim kho, xws li paving txoj kev. Txoj kev paved nrog asphalt thiab gravel tau hu ua asphalt txoj kev.