Influence of Secondary Thermal Compaction on Property of Emulsified Asphalt Cold Recycled Mixture
To quantify the influence of field secondary thermal compaction on the performance of emulsified asphalt cold recycled mixture,based on routine mechanical property test,Overlay Tester reflection crack test,and four-point bending fatigue test under low strain level,the mechanical properties of emulsified asphalt cold recycled core sample and indoor Marshall sample before and after laying hot mix asphalt on site are compared and analyzed.The enhancement influence of field secondary thermal compaction on mechanical properties and durability of emulsified asphalt cold recycled core sample is quantitatively analyzed.The influence of field secondary thermal compaction on microscopic void structure of emulsified asphalt cold recycled mixture is analyzed.The result indicates that the Marshall secondary compaction method recommended by the current regulations cannot simulate the actual field compaction condition well,and the field secondary thermal compaction can significantly enhance the mechanical properties,anti-reflective crack properties,and anti-fatigue durability of cold recycled asphalt mixture.The number of large voids and the diameter of equivalent voids in cold recycled mixture of emulsified asphalt are smaller than those with Marshall molding method.The influence of secondary thermal compaction on voids gradation of cold recycled mixture is significant.The improvement mechanism of field secondary compaction on mechanical properties and fatigue properties of emulsified asphalt cold recycled mixture is that the density of emulsified asphalt cold recycled mixture is enhanced by using the secondary compaction.The micro-void diameter is reduced,and the microscopic void gradation is improved.