Influence Of Phase Change Materials On Temperature And Performance Of Asphalt Mixtures

While the asphalt pavement with its unique advantages in road construction played an important role and has been widely used, it also faces a number of temperature diseases. For such diseases, some technologies such as modifying asphalt, adding fiber, optimized mineral grade composing, are adopted to resolve at home and abroad, but they are passive response to the temperature change in the using process of asphalt pavement with limited effect. This study aimed to explore the feasibility and the key technical issues of phase change materials (PCM) application in asphalt pavement, take advantage of the latent heat characteristics of PCM, active control the using temperature of asphalt mixture, explore new ideas to improve the environmental change adaptability of asphalt pavement.This study comprehensive the existing types and characteristics of PCM, combine the technical requirements of PCM application in asphalt mixture, determine the organic solid-liquid PCM for the test in the end. Through the theoretical analysis of heat conduction and the temperature simulation test of PCM mixed with asphalt mixture, indicated that PCM has a certain role in control the using temperature of asphalt mixture. Road performance test of the asphalt mixture doped with PCM analysis showed that the incorporation of PCM has improved the water stability of asphalt mixture, but high temperature stability and low temperature performance are adversely affected. Splitting strength test results of asphalt mixture doped with PCM and other modifiers show that the incorporation of other modifiers can improve the performance of asphalt mixture, but the effect is limited, and increases material costs. Analysis all the test results, PCM doped in asphalt mixture under high temperature, some PCM may leak from the vector, and soluble in asphalt, so asphalt diluted, making the adhesion between asphalt and aggregate lower, this is the nature reason of the adversely affect to the PCM on the performance of asphalt mixture. In this study, take the sol-gel method to coat the pure PCM as well as PCM with vector as silica fume, floating beads and activated carbon, prepared phase change compound modifier; By scanning electron microscopy and differential thermal analysis experiment show that the phase change compound modifier with activated carbon vector in these types of materials has better characteristics, activated carbon can be used as the preferred PCM vector.