镁铝型水滑石对SBS改性沥青抗老化性能的影响研究

Research on the Influence of Mg-Al-LDH on Anti-aging Performance of SBS Modified Asphalt

采用动态剪切流变仪和弯曲梁流变仪,研究了不同掺量的水滑石(LDH)对SBS改性沥青高温性能、抗疲劳性及低温性能的影响.进行短期热氧老化和紫外老化试验,分别采用傅里叶红外光谱仪和旋转粘度计,对老化前后沥青特征官能团和粘度进行测试,研究不同掺量的LDH对SBS改性沥青抗热氧和光氧老化的影响.结果表明,掺入LDH后,沥青的复核模量增大、相位角减小、抗车辙性能提高;蠕变劲度增大、劲度变化速率减小、沥青的低温性能降低;当LDH掺量不大于4%时,LDH对SBS改性沥青低温性能的降低幅度可控制在一个PG等级.添加LDH后,老化后SBS改性沥青的IC=O和粘度的增大幅度减小、ISBS的减小幅度减小,表明LDH能够提高SBS改性沥青的抗老化和紫外老化性能,且LDH掺量越大,其改性效果越显著.综合LDH对SBS改性沥青技术性能以及抗老化效果的影响,推荐LDH的最佳掺量为4%.

The dynamic shear rheometer（DSR）and bending beam rheometer（BBR）were used to evaluate the influence of LDH with different dosages on the high temperature performance,fatigue resistance and low temperature performance of SBS modified asphalt.In order to study the LDH effect on anti-heat oxygen and light oxygen aging of SBS modified asphalt,the short-term hot oxygen aging and ultraviolet aging tests with Fourier infrared spectrometer and Brookfield viscometer were carried out to test the typical functional groups and viscosity before and after the TFOT and UV aging respectively.The results show that after adding LDH,the composite modulus increases and the anti-rutting performance improves,while the phase angle decreases.Meanwhile,the creep stiffness increases,but the stiffness changing rate will decrease and the low temperature performance will reduce.When the LDH content is lower than 4%,the influence of LDH on the low temperature performance of SBS modified asphalt is controlled within one PG grade.After aging,LDH can decrease the IC=Oand viscosity of SBS modified asphalt,while increase the ISBS,which implies that LDH can improve the thermal oxide and UV aging resistance of SBS modified asphalt.The higher the LDH content,the better the modified effect is.Considering the effect of LDH on the Engineering properties and anti-aging performance of SBS modified asphalt,the optimal LDH content of 4%is recommended.