Study On Test Method And Gradation Optimization Of Cold Recycled Mixture Shaped By Vibratory Compaction

In the past 5 years, the development of the highway construction of our country has reached a new stage. At the end of 2010, the mileage of the asphalt pavement all over the country has been 542.5 thousand kilometers, and the mileage of the freeway has reached 74.1 thousand kilometers. The asphalt pavement that has been built early in our country is gradually getting into a major repair or a second line maintenance period, with which an amount of wasted bitumen mixture will be produced. Compared to hot recycling technique, asphalt pavement cold recycling technique has significant advantages as follows:construction at room temperature, low energy consumption, convenient construction and low construction cost. Therefore, cold recycling technique is a very important research direction in the field of asphalt pavement recycling.At present, the molding way of the cold recycling mixture is mainly the Marshall compact molding and the kneading press molding. The researches of the vibratory press molded cold recycling mixture are very few. This thesis illustrates the strength formational mechanism of the cement stabilized cold recycling mixture, the emulsified asphalt cold recycling mixture and the emulsified asphalt-cement cold recycling mixture in detail, and mainly researches for the experimental methods and the optimized range of graduation of the vibratory press molded cold recycling mixture.The main research findings of the thesis are as follows:Firstly, it is indicated by the results of related theoretic analysis and numerous of indoor tests that the vibratory press method can determinate the optimized water content and the maximum dry density of the cement stabilized cold recycling mixture and the emulsified asphalt-cement cold recycling mixture; The vibratory press method also can be considered as the molding way of the samples used in the performance experiments of the compressive strength, cleavage strength, compressive resilient module and so on.Secondly, the curing method of the samples of the emulsified asphalt-cement cold recycling mixture is the curing experimental method of the materials stabilized with inorganic binders (T0845-2009), which is written in the Test Methods of Materials Stabilized with Inorganic Binders for Highway Engineering (JTG E51-2009). It is of great difference between this method and the one in the past.Thirdly, through related experimental researches, when related indoor experiments of the emulsified asphalt-cement cold recycling mixture are being performed, the feeding order of the material is:pre-blending the stones and cement to be even, then mixing up them with the extra water and the liquid mixture of the emulsified asphalt (the liquid mixture should be slightly stirred). The feeding order is relative simple, and its blending time is shorter. If it were adopted in practical processes of construction, the construction organizations could simplify the process flow of blending, and increasing the productive efficiency.Fourthly, according to the research findings before and the calculation and related experimental researches of the theories of the material aggregate, the optimized range of graduation of the vibratory press molded cement stabilized cold recycling mixture and the emulsified asphalt-cement cold recycling mixture has been elementarily carried out.