A Study On The Properties Of Glass Fiber PEG4000 Composite Asphalt Mixture

The asphalt road is sensitive to the temperature.In the high temperature environment,it is easy to produce rutting,oil flooding and other diseases,shorten the service time of the road surface,and will release a large amount of heat and aggravate the urban heat island effect.In this paper,phase change materials are added to asphalt pavement to reduce asphalt pavement temperature.The results show that the direct incorporation of phase change materials into asphalt mixture can reduce the temperature,but also affect the road performance of asphalt mixture.To achieve the effect of active temperature adjustment without affecting the performance of asphalt pavement,this paper uses polyethylene glycol 4000(PEG4000)with 5%,10%,15% and 20% content to prepare phase change modified asphalt,measure its basic index,record the temperature change of phase change asphalt,select the best content with good temperature adjustment effect and meet the requirements of asphalt performance,and explore the influence degree of direct mixing PEG4000 on high temperature performance in asphalt mixture.Then the glass fiber is added to the phase change asphalt mixture to modify it,the modification effect is studied by experiment,and the optimum content of glass fiber is determined.Finally,the influence of glass fiber on the temperature regulation effect of phase change asphalt mixture is explored through outdoor test.The following conclusions are drawn:(1)PEG4000 has a certain effect on asphalt performance.When the PEG4000 content is 15%,the indexes of phase change modified asphalt meet the requirements,and have good temperature regulation effect,which can be adjusted for about 6?.Marshall test shows that the direct incorporation of phase change materials has an effect on the high temperature performance.When the content of phase change materials is 15%,the stability of phase change asphalt mixture is 34%,lower than that of matrix asphalt mixture;(2)Rutting test found that the dynamic stability of asphalt mixture decreased by about 46% after adding PEG4000.After adding glass fiber,the performance of phase change asphalt mixture is improved to a certain extent.When 0.2% is added,the phase change asphalt mixture is increased by 76%,but the improved high temperature performance of phase change asphalt mixture is still lower than that of matrix asphalt mixture;(3)Semi-circular bending test shows that phase change materials have little effect on tensile strength and tensile strain of asphalt mixture at low temperature,but reduce critical fracture energy and fracture toughness.The glass fiber improves the tensile strength of the asphalt mixture,and when the content is 0.2%,the improvement is the most obvious;(4)The freeze-thaw splitting test shows that phase change materials have little effect on the asphalt mixture without freeze-thaw,but reduce the strength after freeze-thaw.After adding glass fiber,the TSR value of phase change asphalt mixture is increased,which indicates that glass fiber can improve its water stability.When the content is 0.2%,the increase is obvious,but it is still lower than that of matrix asphalt mixture;(5)The PEG4000 of phase change material has the effect of temperature adjustment in asphalt mixture.At ambient temperature of about 40?,the temperature can be cooled about 2?3?,and the temperature adjustment effect of phase change material is basically not affected by adding glass fiber.