为探究石墨烯纳米片(GNPs)对基质沥青路用性能的影响及改性机理,首先采用高速剪切法制备不同GNPs掺量的改性沥青,并通过多应力蠕变恢复试验(MSCR)、动态剪切流变试验(DSR)、低温弯曲梁流变试验(BBR)、差示扫描量热仪(DSC)及导热系数测试仪等手段对GNPs改性沥青的高温性能、低温性能、热性能及感温性能进行深入研究。其次,借助傅里叶红外光谱仪(FT-IR)对改性沥青的化学组成及结构进行表征与分析,从微观角度对GNPs的改性机理进行分析。结果表明:随着GNPs掺量的增大,具有二维层状结构的GNPs能够与热沥青发生较强的亲和作用,有效地对热沥青分子链段产生插层或缠绕,从而限制其在高温时的流动性;虽然GNPs能够增强改性沥青的交联密度,但却阻碍了沥青分子链段的运动,使得沥青试样在低温受荷载时的形变恢复能力下降;GNPs与基质沥青之间仅仅发生了物理作用,并未产生化学反应,二者间的化学兼容性良好,GNPs对基质沥青以物理改性为主。

In order to explore the influence of graphene nanoplates (GNPs) on the pavement properties of base asphalt and its modification mechanism,firstly,modified asphalt with different contents of GNPs were prepared by a high speed shear method.The high and low-temperature performance,thermal property and thermosensitivity were studied by multiple stress creep recovery test (MSCR),dynamic shear rheology test (DSR),bending beam rheometry (BBR),differential scanning calorimetry (DSC) and thermal conductivity meter.Then,Fourier infrared spectrometer (FT-IR) were used to characterize and analyzed the chemical composition of the modified asphalt.The results shown that with the increase of GNPs content,GNPs with two-dimensional layered structure had a strong affinity with hot asphalt,which can effectively produce intercalation or winding of hot asphalt molecular chain segment,thus limiting its fluidity at high temperature.Although GNPs can enhance the crosslinking density of modified asphalt,it hindered the movement of asphalt molecular chain segment,as a result,the deformation recovery ability of asphalt specimen under low temperature loading decreased,and there was only physical interaction between GNPs and asphalt.