Study On Modifying Coal-based Asphalt With SBS By Chemical Method

Asphalt is adhesion and flexibility at room temperature, so they are good road materials. Road asphalt mainly including bituminous petroleum asphalt and coal tar pitch. For prices and production reasons, coal tar pitch would be instead of petroleum asphalt for road construction. Coal tar pitch is more volatile and aging, also, it is temperature-sensitive. So, it need to be modified to overcome these shortcomings.Coal tar pitch is used as the raw materials in paper, SBS as the modifier is reacted with coal tar pitch under the catalysis of boron trifluoride diethyl ether to obtain the modified asphalt. Compared with raw coal tar pitch and modified asphalt, Chemically modified coal tar pitch with SBS have better road performance just as higher softening point,smaller penetration and ductility. Theology properties analysis shows that the modified asphalt has better flexibility and a wider temperature change range, and thermal analysis shows that the modified asphalt has more stable performance. It can be seen from SEM that compared with the raw bitumen, the modified asphalt has flatter cross-section and more uniform structure, SBS has been fully integrated with asphalt. FT-IR showed that a chemical reaction occurred between asphalt and SBS.