Study On The Performance Of High-content Desulfurization Rubber Powder Modified Asphalt And Its Mixture

Nowadays,there are high-temperature oil flooding,low-temperature cracking and other phenomena on the most commonly-used SBS modified asphalt pavement,which seriously affects the road performance.Besides,asphalt is very precious as a non-renewable resource.Rubber powder modified asphalt can not only improve pavement performance but also reduce the amount of asphalt.However,it is difficult to popularize because of its low content and high degree of segregation.The mixing content of desulfurization rubber powder modified asphalt at home and abroad is about 20%.The paper studies preparation of modified asphalt with 30% desulfurization rubber powder and studies its conventional performance,aging performance,high and low temperature performance,segregation performance,rheological properties,modification mechanism,high and low temperature and water stability of the mixture.The advantages of desulfurization rubber powder modified asphalt were shown by comparison with the performance of SBS modified asphalt.The main results of this paper are as follows:(1)On the basis of the modified asphalt research of desulfurization rubber powder at home and abroad,SBS,hardener A,stabilizer B and desulfurizer C were added to prepare the desulfurization rubber powder modified asphalt which mixed with 30% desulfurized crumb rubber.Combined with modified asphalt segregation,penetration degree,ductility and softening point test,the formula of desulfurization rubber powder modified asphalt was studied.The final content of the four additives is determined as follows: the content of SBS is 2%,the content of hardener A is 1%,the content of stabilizer B is 0.6%,and the content of sulfur supplement C is 0.6%.The conventional properties and rheological properties of 30% desulfurized rubber powder modified asphalt were studied.The results show that 30% desulfurized rubber powder modified asphalt has better aging durability,segregation performance,heat storage stability and rheological properties than SBS modified asphalt.(2)The functional group and thermal stability of modified asphalt with large mixed desulfurization rubber powder and the modified mechanism of desulfurization rubber powder modified asphalt was analyzed in this paper,after the infrared spectroscopic test,thermal weight test and thermal stability test of 30% large mixed desulfurization rubber powder modified asphalt.Functional group results shows that the swelling reaction of light components absorbed by desulfurized rubber powder occurs mainly in the preparation process of modified asphalt.Thermogravimetrictest results show that the Thermal stability of high-content desulfurization rubber powder modified asphalt is better than that of SBS modified asphalt,the temperature at the beginning of mass loss is higher than that of SBS modified asphalt,the mass loss at the same temperature is less than that of SBS modified asphalt,the endothermic peak area is smaller than that of SBS modified asphalt,temperature sensitivity is lower than SBS modified asphalt.The thermal stability of three kinds of asphalt is: desulfurization rubber modified asphalt > SBS modified asphalt > base asphalt.(3)The mix ratio and optimal asphalt ratio of modified asphalt mixture were calculated,and 30% large mixed modified asphalt powder densely equipped with ARHM16(W)mixture was configured to study its applicability.The results of high temperature rutting test show that the dynamic stability of 30% admixed desulfurization glue powder modified asphalt mixture is 1.23 times that of SBS modified asphalt;The low temperature crack resistance test showed that its bending stiffness modulus at low temperature is 1.20 times that of SBS modified asphalt.The water stability test shows that in terms of the ability to resist water damage,although the splitting strength ratio and residual stability of the desulfurized rubber powder modified asphalt mixture have increased by 1%～2%,the splitting strength and Marshall stability of the desulfurization rubber powder modified asphalt mixture are higher than that of SBS modified asphalt.Splitting strength before freezing and thawing is 1.23 times of SBS modified asphalt mixture.Marshall stability is 12.65% higher than that of SBS modified asphalt mixture.The splitting strength before freezing and thawing is 1.23 times that of SBS modified asphalt mixture,and the Marshall stability is 12.65% higher than that of SBS modified asphalt mixture.(4)The 30% desulfurization rubber powder modified asphalt mixture was applied to Jingde highway.The production process,mixture production temperature,construction technology and performance index requirements of desulfurization rubber modified asphalt were presented here.The field application results show that 30% desulfurization rubber powder modified asphalt can effectively reduce the use of base asphalt.The cost of ARHM16 mixture modified by desulfurization rubber powder is 2.77% lower than that of SBS modified AC13 mixture and 16.14% lower than that of SBS modified SMA13 mixture.