改性硬质沥青的流变学性能研究

Research on rheological properties of modifi ed hard asphalt

以50号沥青、SBS和胶粉为主要原料制备三种改性硬质沥青。利用动态剪切流变仪(DSR)和弯曲梁流变仪(BBR)对改性硬质沥青的高温黏弹性和低温蠕变性能进行评价。结果表明:复合改性沥青的模量、车辙因子最大,其次是胶粉改性沥青、SBS改性沥青,三种改性硬质沥青的高温性能优劣顺序为:复合改性沥青>胶粉改性沥青>SBS改性沥青;根据三种改性硬质沥青的S和m值,确定低温性能优劣顺序为:复合改性沥青>胶粉改性沥青>SBS改性沥青;SBS、胶粉和胶粉/SBS复合改性硬质沥青的PG等级分别为PG 92-22、PG 82-22和PG 82-22;通过分析三种改性硬质的沥青黏温特性,确定施工和易性优劣顺序为:SBS改性沥青>胶粉改性沥青>复合改性沥青。

Three modified hard asphalts were prepared by using 50#asphalt,SBS and crumb rubber(CR)as the raw materials.The high temperature viscoelastic and low temperature creep properties of modified hard asphalts were evaluated by dynamic shear rheometer(DSR)and bending beam rheometer(BBR).The results show that the modulus and rutting factor of composite modified asphalt is the largest,followed by CR modified asphalt and SBS modified asphalt.The order of high temperature properties of three hard modified asphalts is:composite modified asphalt>CR modified asphalt>SBS modified asphalt.According to the S and m values,the order of low temperature properties of three modified hard asphalts is determined as follows:composite modified asphalt>CR modified asphalt>SBS modified asphalt.The PG grades of SBS,CR and CR/SBS composite modified hard asphalts are PG 92-22,PG 82-22 and PG 82-22,respectively.By analyzing the viscosity-temperature characteristics of three modified hard asphalts,the order of their workability can be determined as follows:SBS modified asphalt>CR modified asphalt>composite modified asphalt.