Research On Sequences And Pilot Test Of MEPCTA In Highway Construction

With continuous development of the scientific research of highway in our country, theresearches on materials and structure of pavement have been developed by scholars at homeand abroad. However, the functional performance of pavement is still significantly affected bydiseases associated with temperature, such as high-temperature rutting, low-temperature crack.Domestic and foreign researchers carry out the researches to reduce adverse effects passivelywhen facing changes in ambient temperature by using modified bitumen, mixing withanti-rutting agent, optimization of mineral aggregate gradation composition, reinforcementcement concrete, improving joint construction technology and the joint material, and so on.However, the effect isn’t obvious enough. With the spirit of sustainable development, thisstudy attempts to mix the phases change material (PCM) to pavement to improve thetemperature stability of asphalt pavement actively.Because of the difference between the damages caused by different temperature, threethermoregulation sequences are proposed depending on the phase change temperature of PCM:Low temperature sequence (-5℃~5℃); High temperature sequence (35℃~50℃); Mixingsequences (5℃~35℃). The change discipline of the three sequences with diverse PCMs andtheir dosage is introduced by the results of different proportion mixtures of Tetradecane, solidparaffin and liquid paraffin. The reasonable mixing ratio is put forward. In order to avoid theproblem of leakage when applied in highway construction, this study improves thepreparation method of Micro-encapsulated phase change thermoregulation agent (MEPCTA),explains the preparation mechanism and determine the preparation parameter. UsingTetradecane as PCM, Differential Scanning Calorimetry(DSC) result of the preparedMEPCTA proves that the phase change enthalpy and temperature satisfies the requirement.The indigenous-designed instrument is used to preparation of large number of MEPCTAwhich will simplify the preparation of MEPCTA and save the resources. The experimentverifies that the preparation stability of the instrument is pretty well. After heated at thetemperature of140℃,160℃,180℃for5minites, the high temperature stability test provesthat the microcapsule composite shape-stabilized phase change material is proper to avoid theheat leakage problem. The cement mortar with MEPCTA shows that MEPCTA can reduce the heating (cooling) rate of specimen temperature, delay occurrence of the highest (lowest)temperature, and improve the specimen adaptability to the environment temperature. After thelaboratory study and pilot test, the study brings forth the product standard to the application ofMEPCTA.