基于正交试验基质沥青自愈合性能影响因素研究

Study on Factors Influencing Self-healing Performance of Matrix Asphalt Based on Orthogonal Test

沥青材料作为一种黏弹性物质,具有自愈合性能。为研究影响70#基质沥青的显著性因素,设计正交试验选取了间歇温度、间歇时间、损伤度三个因素并采用动态剪切流变仪进行“疲劳-愈合-疲劳”试验,根据极差、方差得到各因素对自愈合性能指标的影响。结果表明:影响自愈合性能指标HI_(1)的主要因素是间歇时间,间歇温度和损伤度几乎无影响,认为采用指标HI_(1)评价基质沥青的自愈合性能欠妥;对影响自愈合性能指标HI_(2)的因素显著性排序为间歇温度>间歇时间>损伤度,且随间歇温度的升高、间歇时间的延长将大幅提高沥青材料的自愈合程度;自愈合指标HI_(3)"考虑了加载次数与模量的联系,从而对自愈合指标HI”3修正得到,各因素对指标的显著性HI_(3)"排序为损伤度>间歇温度>间歇时间,且随着损伤度的增大,自愈合程度逐渐降低,体现自愈合性能良好的最优组合为间歇温度30℃、间歇时间4 h,损伤度10%。

As a viscoelastic material,the asphalt material has the self-healing property.In order to study the significant factors affecting 70#matrix asphalt,three factors of intermittent temperature,intermittent time and damage are selected to design the orthogonal test,and a dynamic shear rheometer is used to carry out the"fatigue-healing-fatigue"test.According to the range and variance,the influence of each factor on the self-healing performance index is obtained.The results show the main factor affecting the healing performance index HI1 is the intermittent time,while the intermittent temperature and the damage degree have little influence.It is considered that the index HI_(1) is not appropriate to evaluate the self-healing performance of matrix asphalt.The significance ordering of the factors influencing the self-healing performance index HI_(2) is the intermittent temperature>intermittent time>damage degree,and with the increase of intermittent temperature and time,the self-healing degree of asphalt will be greatly improved.By considering the relationship between loading times and modulus,the self-healing index HI_(3)"is modified.The significance HI_(3)"ordering of each factor to the index is the damage degree>intermittent temperature>intermittent time,and with the increase of damage degree,the self-healing degree gradually decreases.The optimal combination of reflecting the good self-healing performance is 30℃ intermittent temperature,4h intermittent time and 10%damage degree.