| Highway transportation plays an important role in Chinese transportation industry.In the process of highway construction,asphalt concrete is widely used for its good road performance.However,the high temperature damage of asphalt concrete has some negative impacts on road durability,traffic safety and ecological environment,and can bring huge difficulty to road maintenance.At present,some people try to solve this problem by modifying asphalt,adding fiber and optimizing gradation.They have made some progress.In addition,the technical means for self-regulation of road surface temperature is also a research focus.Nowadays,researchers attempt to realize self-regulation of road surface temperature by adding phase change materials into asphalt concrete.They already carried out some performance and feasibility analysis experiments of road surface temperature regulation.As energy storage materials,phase change materials possess characteristics of energy saving and environmental protection,and they can be applied to temperature control and realize the self-regulation of road surface temperature by taking advantage of their latent heat.In this paper,polyethylene glycol was optimized according to the requirements of pavement temperature control technology,and it was used as the basic temperature control material.Then,two porous materials,including almond shell biochar and silica,were used as carriers to adsorb and fix polyethylene glycol by vacuum impregnation method.Two kinds of formstable composite phase change materials were prepared.Different test methods were used to test the properties of two kinds of form-stable composite phase change materials.The results showed that polyethylene glycol maximum content,melting enthalpy,solidification enthalpy,melting point temperature and freezing point temperature of polyethylene glycol/silica are 51.1%,70.44 J/g,62.16 J/g,52.69 ? and 38.19 ?,respectively.The values for these parameters of polyethylene glycol/almond shell biochar are 52.6%,82.73 J/g,78.76 J/g,52.47 ? and 38.87 ?,respectively.Both of the two kinds of form-stable composite phase change materials possess good heat storage characteristics and thermal stability,and they are suitable for road temperature control.In this paper,two form-stable composite phase change materials were prepared aiming at the problem of high temperature damage of asphalt concrete road,and their application prospects in temperature control of asphalt concrete road were analyzed.It provides more possibilities for the choice of road temperature control materials. |
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