Based on the specifications of ASTM D571095 and BSI BS-3690 for Trinidad Lake Asphalt(TLA) modified asphalt,two residues(CLA1 and CLA2)from direct coal liquefaction(DCL) were evaluated for using as high grade paving asphalt modifier.TLA was used as comparison.The results show that CLA1-and CLA2-modified asphalt with 7% of CLA1 or CLA2 addition has similar modification ability as 20% TLA-modified asphalt.The modified asphalts meet the specifications for 40～55 or 50 penetration grade.The penetration ratio of CLA2-modified asphalt after TFOT is significantly higher,which indicates its supreme ability to against the temperature aging.Preliminary study implies that DCL residues may be a suitable alternative additive for producing TLA-type modified asphalt.Furthermore it was also found that with increasing amount of CLA1 or CLA2 addition the softening point of the modified asphalts increase and the penetration value and the ductility decrease.
