Study On Compaction Characteristics And Road Performance Of REOB Modified Emulsified Asphalt Cold Recycling Mixture

Nowadays,the development of China's highway industry can be described as very rapid.With the large number of newly-built highways already put into use and the years of service life increasing,more and more highways have entered the stage of "large and medium repair" and maintenance,so a lot The waste asphalt mixture,the pile of waste asphalt mixture not only takes up a lot of land resources,but also causes serious environmental pollution.Cold recycling technology can make full use of waste asphalt mixture,which not only saves resources,but also reduces environmental pollution.At present,most of the emulsified asphalt used for mixing cold recycled asphalt mixture is ordinary emulsified asphalt,and the use of modified emulsified asphalt mixed with recycled materials is relatively small.Therefore,the main research contents of this paper are as follows:(1).Through indoor tests,the relevant tests of REOB modified emulsified asphalt cold recycled mixtures are used.The old asphalt mixture used is RAP material on the right side lane of a highway of G339 national road,and self-made simulated RAP material.Use ordinary emulsified asphalt,modified emulsified asphalt with REOB content of 2%,4%,6% and the above two RAP materials to mix refrigeration regenerated asphalt mixture,and through the macro and micro tests,it was compacted Research on characteristics;(2).RAP material milled on a second-grade highway in Rizhao,mixed with ordinary emulsified asphalt and REOB with modified emulsified asphalt of 4% and 8%,respectively,through refrigeration and regenerated asphalt mixture,passed rut test,low temperature bending The tests,Marshall stability test and semi-circular bending test conducted a comparative analysis of its high-temperature stability,low-temperature crack resistance,water stability and fatigue resistance.Through laboratory tests,the following conclusions were drawn:(1).In the case of mixture gradation and other influencing factors are the same,the compaction characteristics of cold recycled asphalt mixture mixed with RAP material is better than that of cold recycled asphalt mixed with new aggregate.The compaction characteristicsof the mixture are poor,and the old asphalt on the surface of the RAP has an obstructive effect on the compaction characteristics of the mixture;(2).The factors that affect the compaction characteristics of the mixture are changed.Through laboratory tests,the effects on the compaction characteristics of the mixture are obtained.The degree of significance is in order of emulsion temperature> molding temperature> type of recycled materials> mixing temperature> mixing time> REOB blending amount.The compaction characteristics of the mixture made by mixing REOB modified emulsified asphalt are better than that of blending with the addition of regenerant The compaction characteristics of the prepared mixture are very small;(3).The industrial CT scanner is used to scan the formed test piece.The internal emulsified asphalt mixture test piece has large internal pore size,large number,and relatively large gaps.The internal pore size of the emulsified asphalt mixture with REOB is relatively small,the number is relatively small,and the distribution of voids is relatively dispersed.Therefore,the addition of REOB significantly reduces the inside of the mixture.The size and number of voids have a significant improvement on the compaction characteristics of the mixture;(4).Under the same gradation of the RAP material used,compared with the ordinary emulsified asphalt cold regeneration mixture,the emulsified asphalt mixed with REOB is cold The high temperature stability performance of the recycled mixture is slightly reduced,and the low temperature crack resistance,water stability performance and fatigue resistance have been improved.The AMPT test machine is used to perform dynamic modulus on the ordinary emulsified asphalt mixture and REOB modified emulsified asphalt mixture specimens.According to the measurement,the dynamic modulus of the mixture under different influencing factors has different degrees of change.Properly increasing the mixing temperature of the mixture and the number of rotation compaction can reduce the dynamic modulus of the asphalt mixture.