Study On Crack Resistance Of Coarse Aggregate GAP Semi-open Gradation Asphalt-streated Permeable Base

The cracking of semi-rigid base course under the action of vehicle load is upward reflects gradually,which causes the cracking of asphalt overlay.It is one of the urgent problems to be solved by road researchers at present.In order to enhance the ability to resist reflective cracking of asphalt pavement structure,the team from improving crack resistance of asphalt stabilized macadam mixture as a starting point,a kind of coarse aggregate discontinuous half gradation asphalt stabilized macadam(GSOG-25)has been designed,as a surface crack of the asphalt layer.This paper revolves around GSOG-25 mixture the crack resistance of the core issues,the following aspects of work has been done:After selecting gradation,this study mainly done the following aspects of the work on the core issue of the crack resistance of GSOG-25:Semi-circular bending tests was made for AC-25,ATB-25,ATPB-25 mixture material at different temperatures.The fracture toughness parameters KIC and JIC at different temperatures to made evaluation of the cracking resistance of materialsare obtained.The effects of gradation,asphalt-aggregate ratio,and temperature to the cracking resistance of materials were also analyzed.Load-bearing reflection crack indoor simulation tests were made for AC-25,ATB-25,ATPB-25 and GSOG-25 mixture materials.Initial and final cracking life of all materials with different thickness were obtained.The results show that the anti-reflective cracking ability of GSOG-25 mixture material is the best.The layer bottom stress and reflection crack propagation life are fitted to know the correlation between them.Shear fatigue cracking performance of GSOG-25 mixture material was studied by double shear fatigue test.Shear fatigue life when the stress ratio are 0.1,0.2,0.3,0.4,0.5 was obtained.The results indicate that the fatigue life under different stress ratios are all subject to the double parameter Weibull distribution.Shear fatigue equations of GSOG-25 mixture material under different failure probability were developed.