基于力学试验研究再生沥青混凝土的拌合模式

Experimental Study Based on the Mechanics of the Recycled Asphalt Concrete Mixing Mode

通过一系列力学试验探讨不同老化等级的旧料(RAP)在再生沥青混合料(RAC)实际拌合过程中的扮演模式。选取两种不同老化等级的RAP(掺量40%),按目标黏度200 Pa·s求得所需添加的新沥青用量及等级。并按黑石头拌合、完全拌合、实际拌合三种不同拌合模式,在最佳沥青用量下分别制作RAC试件。通过一系列力学试验分别求取RAC的力学参数,如动态模量、重复荷载下RAC试件永久变形量及流动数、三轴剪力强度试验摩尔库伦破坏包络线参数c、ψ值。根据数据分析并比较此两种不同老化等级的RAP在RAC实际拌合过程中所扮演的模式。结果表明,普通老化RAC完全拌合与实际拌合间力学参数的差异较小,表示黑石头现象不明显,完全拌合与实际拌合较接近;在过度老化RAC中,实际拌合试件的试验数据与完全拌合间的差距比普通老化RAC大,表示过度老化RAC在实际拌合过程中新、旧沥青间未达到充分混合,而有较明显的黑石头现象,拌合效益发挥有限。

In this paper,through a series of mechanical test to explore old material with different levels of aging（ RAP） in the regeneration asphalt mixture（ RAC） play in the process of actual mixing mode. Choose two different grades of RAP aging（ content 40%）,according to the target viscosity 200Pa·s parking required to add new asphalt content and level are obtained. And by the black stones mixing,fully mixing,mixing and so on three different mixing mode,making RAC specimen respectively under the optimum asphalt content. Through a series of mechanical test respectively to calculate the mechanical parameters of the RAC（ such as the dynamic modulus,RAC specimen permanent deformation under repeated load and the number of flows,triaxial shear strength test Moore coulomb failure envelope parameters c,bits of value. According to the data,analysis and compare the two different aging level of RAP in RAC plays in the process of actual mixing model. The results showed that normal aging RAC complete mixing and mechanical parameters of differences between actual mixing is lesser,said the phenomenon of the black stone is not obvious,fully mixing with actual mixing closer; in excessive aging RAC,actual batch test data of the specimens and the gap between the complete mixing than normal aging RAC,said excessive aging RAC in the mixing process between the new and old asphalt mix has not been achieved,and has the obvious phenomenon of black stone,mixing the benefit of the play is limited.