Research On The Performance Of Large Particle Crushed Stone Filled With Cement Stabilized Macadam Base Material

Cement stabilized macadam semi-rigid base course has the advantages of good integrity,high rigidity,good water stability,good economy,etc.,and has become the most widely used type of base course of various grades of highway in China.However,conventional cement stabilized macadam bases often cause shrinkage cracks due to changes in humidity and temperature during early construction and maintenance.During the use of roads,vehicle loads and temperature loads cause fatigue damage to the bases,which causes reflective cracks in asphalt pavements.Greatly reduced road life.In this paper,a new type of pavement base material——large particle crushed stone filled with cement stabilized macadam base material is studied.The large particle crushed stone filled with cement stabilized macadam base material with large sized crushed stone as the load-bearing skeleton.The cement stabilized macadam filled in the space of the skeleton.The lack of a rigid base layer delays the early shrinkage cracks in the base layer.Its modulus is lower than conventional cement stabilized macadam material,which is used to overcome the shortage of traditional semi-rigid base layers and delay the early shrinkage cracks of the base layers.In order to fully understand the mechanical properties and crack resistance of large particle crushed stone filled with cement stabilized macadam base material,this article mainly studies the following:(1)First,on the basis of summarizing the design theory of suspended dense structure and skeleton dense structure,the dense skeleton structure was selected as the structure of the large particle crushed stone filled with cement stabilized macadam base material structure.With reference to the Belay method,the proportion composition of each particle size aggregate of large particle crushed stone filled with cement stabilized macadam base material was determined.(2)Secondly,test specimens of large particle crushed stone filled with cement stabilized macadam base material are prepared,and their mechanical properties such as unconfined compressive strength,compressive rebound modulus and flexural tensile strength,and durability such as early drying shrinkage and temperature shrinkage are performed.The laboratory test study analyzed the strength development process and shrinkage characteristics of the large particle crushed stone filled with cement stabilized macadam base material.(3)Then,a two-dimensional digital model of the large particle crushed stone filled with cement stabilized macadam base material is established,and the dry shrinkage and compression cracking test simulation is performed by using ABAQUS software.From the perspective of energy and cracking form,the advantages of the large particle crushed stone filled with cement stabilized macadam base material compared with conventional cement stabilized crushed stone material in terms of crack resistance are analyzed.(4)Finally,the kenpave pavement analysis software is used to analyze the macro-mechanical behavior of the pavement structure of the large particle crushed stone filled with cement stabilized macadam base course.The response surface method is used to obtain the influence of the thickness of the base layer and the modulus of the material on the permanent deformation of the asphalt surface layer and the maximum tensile stress of the base layer.