生物炭改性沥青的路用性能

Road properties of bio-char modified asphalt

为改善沥青的路用性能并兼顾环境效益,选择生物炭对沥青进行改性,采用高速剪切法制备不同掺量的生物炭改性沥青,通过沥青三大指标试验、60℃动力黏度试验、布氏旋转黏度试验(RV)、旋转薄膜烘箱老化试验(RTFOT)等对其进行性能评价。试验结果表明,生物炭可有效提高沥青材料的高温性能及温度稳定性,其掺量达到12.5%时改性效果为最佳;生物炭改性沥青的动力黏度和布氏黏度均随生物炭掺量的增加而不断增大,表明生物炭改性剂具有显著的增稠作用,可提高改性沥青的黏结及抗流动变形能力;不同生物炭掺量的残留针入度比均高于基质沥青的,软化点增量均小于基质沥青的,生物炭改性沥青的抗老化性能得以改善。此外,生物炭沥青的应用具有良好的环境效益和经济效益。

In order to improve the road properties of asphalt and to take into account the environmental benefits, bio-char was used to modify asphalt. T h e high-speed shear method was used to prepare bio-char modified asphalt of different percentages. Three-index test,60℃ dynamic viscosity test,RV test,RTFOT test on the asphalt were conducted to evaluate road performance of the bio-char modified asphalt. The results s how that the addition of bio-char can improve the high temperature properties and temperature stability of the modified asphalt, and that the modification effect is optimal when the percentage of bio-char is 12. 5 % . Both dynamic viscosity and Brookfield viscosity of the bio-char modified asphalt can be enhanced with the increasing proportion of bio- cha r,which indicates that bio-char can strengthen the bon d capability and resistance to flow deformation of the modified asphalt. Compared with the matrix asphalt,the modified asphalt with different percentages of bio-char has higher residual penetration ratio and lower softening point increment,revealing thatthe use of bio-char can improve the ageing resistance of the modified asphalt. In addition, the application of bio-char modified asphalthas excellent environmental benefits and economic efficiency.