橡胶/聚酯纤维沥青混合料低温抗裂性能研究

Research on low temperature fracture toughness of rubber powder/polyester fiber asphalt mixes

以橡胶粉(RP)、聚酯纤维(PET)、橡维联(TOR)为沥青改性剂,基于响应面模型研究改性剂质量分率对试件低温(-30℃)断裂韧性的影响。利用方差分析(ANOVA)发现,RP和TOR是影响断裂韧性的显著主效应,RP×PET和PET×TOR是影响显著的交互效应,RP^(2)、PET^(2)和TOR^(2)是影响显著的二次效应,这与帕累托图的结果吻合。随着3种改性剂质量分率的增加,试件低温断裂韧性先升高后降低,当橡胶粉质量分率为4%时,平均断裂韧性最高,为40.36MPa·mm^(0.5);当橡维联质量分率为0.8%时,低温断裂韧性最高,为40.16MPa·mm^(0.5)。当橡胶粉与聚酯纤维质量分率分别为4%和0.5%时,试件断裂韧性最高,两者存在协同效应。当橡胶粉、聚酯纤维和橡维联质量分率分别为3.77%、0.52%和0.84%时,试件低温断裂韧性为43.54 MPa·mm^(0.5),实验值为42.67 MPa·mm^(0.5),两者非常吻合。

Using rubber powder(RP),polyester fiber(PET)and rubber vinylidene(TOR)as asphalt modifiers,the effects of the modifier mass fraction on the low-temperature(-30℃)fracture toughness of specimens were studied based on a response surface model.Through ANOVA,it was found that RP and TOR were significant main effects,RP×PET and PET×TOR were significant interaction effects,RP^(2),PET^(2) and TOR^(2) were significant secondary effects,which was consistent with the results of the Pareto plot.As the mass fraction of the three modifiers increased,the low-temperature fracture toughness of the specimens first increased and then decreased.When the mass fraction of rubber powder was 4%,the average fracture toughness reached the highest with the value of 40.36MPa·mm^(0.5);When the mass fraction of TOR was 0.8%,the low-temperature fracture toughness reached 40.16MPa·mm^(0.5).When the mass fraction of rubber powder and polyester fiber were 4%and 0.5%,respectively,the fracture toughness of the specimens were the highest,and there was a synergistic effect between these two factors.When the mass fractions of RP,PET and TOR were 3.77%,0.52%and 0.84%,respectively,the low-temperature fracture toughness of the specimens were 43.54MPa·mm^(0.5),and the experimental value was 42.67 MPa·mm^(0.5),which was very consistent.