The Development And Performance Evaluation Of Phase Change-Cold Mix Asphalt Mixture

Asphalt pavement was already widely applied in the field of transportation such as various grades highways,urban roads,airport roads,but the construction process with the pollution of the environment and the process of using with the high temperature disease,had been restricting the asphalt mixture pavement's development.This paper relied on the National Natural Science Foundation of China,and prepared a new type of composite phase change material with the combination of theory and experiment,the new type of composite phase change would be applied to the cold mix asphalt mixture.The temperature of the cold mix asphalt pavement would be reduced in high temperature environments through thermal storage properties of phase change material,thereby enhancing the high temperature stability of cold mix asphalt mixture.The study broadened the applications of phase change materials and had great significance for cold mix asphalt mixture technology promotion.In this paper,according to the pore size of an inorganic porous substrate,the porous substrate was divided into the millimeter porous matrix,micron porous matrix,nanometer porous matrix.Selected the volcanic rock,expanded graphite,zeolite as their representative.Prepared paraffin-millimeter porous matrix composite phase change material,paraffin-micron porous matrix composite phase change material,paraffin-nanometer porous matrix composite phase change material.By testing the various performances of three types of phase-change materials,combined with the preparation process and the actual usage of cold mix asphalt mixture,selecting paraffin-micron porous matrix composite phase change material was suitable for cold mix asphalt mixture.Its phase change enthalpy was 122.9J/g,the peak temperature was 51.9? the thermal conductivity was 3.2358 W/(m.k).It would maintain good high temperature stability,when the temperature was less than 200 ?.Prepared phase change-cold mix asphalt mixture which the phase change material dosage was 3%,5%.Selecting the hot season,texted outdoor temperature measurement,analysis of the experimental results showed that,when the phase change material dosage was 3%,reduced pavement temperature about 3.2?;when the dosage reaches 5%,reduced pavement temperature about 5.2?.Phase change material played a good inhibition to the pavement high temperature disease,alleviated the urban heat island effect effectively and increased comfort of environment.Combined with the relevant norms,texted the pavement performance of phase change-cold mix asphalt mixture.The results showed that,the phase change-cold mix asphalt mixture had better mechanical properties,high temperature properties and water stability properties.With the increased dosage of phase change material,the asphalt mixture's low temperature performance would be reduced.It was recommended that avoided this type of asphalt mixture applied in the alpine region.