Influence of Compacting Methods on Grade Macadam Shear Characteristics

The shear strength and stress-strain relation of graded macadam in Vibrating Compaction (VC) and the Modified Proctor Compaction (MPC) were studied and compared , and the reasons of cause those difference were analyzed. Applying medium scale triaxial apparatus , the shear strength of grade macadam were carried out , the influence of different compaction methods on shear strength was proclaimed. Triaxial test results show that , peak stress , residue strength and initial modulus of VC sample increases 22 % , 20 % and 90 % respectively comparing with that of MPC sample , while failure strain decreases 10 %; for the strength parameters , friction angle increases 2 degree , C value increases 38 % , and shear strength increases 20 % than that of Modified Proctor Compaction action of Vibrating Compaction is strong than that of Modified Proctor Compaction.So , Vibrating Compaction should be applied widely in projects in order to enhance shear strength of grade macadam.