Preparation And Performance Study Of Anti-coagulation Ice Phase Change Energy Storage Cement-based Materials

Frost,ice and snow on the road surface in winter will reduce the friction coefficient of the road surface,easily cause traffic accidents,and threaten the safety of people’s lives and property.Since the phase change material will generate a lot of heat during the phase change process,the phase change material with a phase change temperature of 0 ～ 5 ℃ is added to the concrete to prepare the phase change energy storage concrete,which can play a certain role in the pavement bridge surface.The effect of melting snow and deicing delays the time of frost and icing on the pavement and bridge deck.In this paper,decanoic acid and octanoic acid(mass ratio of 0.3:0.7)are used to prepare composite phase change materials with a phase transition temperature of 0～5℃.Step cooling curve and DSC curve are used to analyze.The latent heat of phase change is 121.9J/g,which meets the needs of practical applications.Since the thermal conductivity of the decanoic acid-octanoic acid composite phase change material is relatively small and the heat transfer performance is relatively poor,it is necessary to improve its thermal properties.Choose nano-copper powder,nano-alumina,nano-iron oxide and graphite powder as additives to improve the thermal performance of phase change materials.When the mass fraction of graphite powder is 15%,the effect is the best.At this time,the phase change temperature is 1.59℃.Compared with the capric acid-octanoic acid composite phase change material,the phase change time of the phase change material added with graphite powder is 85 min increased by 13.33%,the phase change latent heat was 130.4J/g increased by 6.97%,and the thermal conductivity was 0.529W/(m·K)increased by 91.67%.Expanded perlite and ceramsite are used as carrier materials,and the adsorption rates of expanded perlite and ceramsite under vacuum adsorption conditions are 202.2% and 27.5%,respectively.Epoxy resin and cement are used to encapsulate and expand the perlite shell.After 300 phase transition cycles,the leakage rate of the phase change aggregate is only 2.37%.Direct mixing technology is adopted to replace fine aggregate in concrete with phase-change aggregate according to mass ratio.Test the mechanical properties,thermal properties and durability of phase change concrete.With the increase of sand-replacement rate of phase-change aggregates,the compressive strength,flexural strength and splitting tensile strength of concrete all show a decreasing trend.When the sand replacement rate of the phase-change aggregate is 30%,it can still meet the requirements of C30 concrete;at this time,the concrete has good phase-change performance and the phase-change temperature is 2.5 ° C;it has been verified by experiments that 1m3 of concrete can be released at this time The heat output of about 13087.96 k J can achieve a certain effect of delaying frost and icing.The addition of phase change materials has little effect on the mass loss and strength loss of the phase change concrete after freeze-thaw cycles;after multiple phase change cycles,the phase change temperature of the concrete is almost unchanged,and the heat released is reduced by 10.53%,the phase change Energy storage concrete has good durability and can meet the requirements of long-term use.