煤直接液化残渣对沥青-集料黏附性的影响

Effect of Direct Coal Liquefaction Residue on Adhesion Characteristic Between Asphalt and Aggregate

为评价煤直接液化残渣(Direct Coal Liquefaction Residue,DCLR)对沥青与集料黏附性的影响,基于表面自由能理论,以SK-90沥青为基质沥青,以石灰岩为集料,利用躺滴法分别测试不同DCLR掺量下(0%、2%、4%、6%、8%、10%,掺量表示DCLR与SK-90质量比,下文同)改性沥青在不同老化阶段(原样、短期老化以及长期老化)的表面自由能,计算不同老化阶段不同DCLR掺量下沥青的黏聚功,以及无水和有水条件下不同DCLR掺量的改性沥青在不同老化阶段与石灰岩之间的黏附功和剥落功,并采用黏附功、黏聚功之和与剥落功的比值作为水稳定性能评价参数来评价沥青-集料间的水稳定性能。试验结果表明:DCLR加入后,随着掺量的增加会提高沥青自身的重均分子量和极性基团含量,从而提高DCLR改性沥青表面自由能中的极性分量、非极性分量以及黏聚功;DCLR改性沥青-石灰岩之间的黏附功、水稳定性能等均随着DCLR掺量的增加而逐渐增加,说明加入DCLR并增加其掺量会显著提高沥青与石灰岩之间的黏附性和水稳定性能,但沥青的老化对DCLR改性沥青-石灰岩之间的黏附性及水稳定性能影响不大。

The surface free energy theory was used to evaluate the effect of direct coal liquefaction residue（DCLR）on adhesion characteristic between the asphalt and aggregate.The virgin asphalt was SK-90,and the aggregate was limestone.The surface free energies of SK-90 asphalt and the modified asphalts with different DCLR contents（0,2%,4%,6%,8%,10%by mass of SK-90 asphalt）were measured using the sessile drop method at different aging stages（Un-aged,RTFOT,and PAV）.The cohesion works of asphalt with different DCLR contents,the adhesion works and splitting works between modified asphalts and limestone with water and an hydrous conditions at different aging stages were calculated.The moisture susceptibility was determined using the ratio of the sum of adhesion and cohesion works to splitting work as the parameter.The test results show that the polar and non-polar components,surface free energies,and cohesionworks improve owing to the high-average molecular weight and polar group contents rising upon the addition of DCLR.The adhesion works between modified asphalts and limestone at different aging stages increase with the DCLR contents.The results suggest an improvement of the adhesion characteristics and moisture susceptibility between asphalt and limestone with the addition of DCLR.However,these properties are not much affected by the aging stage.