加热方式对SBS改性沥青混合料愈合效果的影响

Effect of Heating Method on the Healing Effect of SBS Modified Asphalt Mixture

为研究加热方式对苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrene-butadiene-styrene block copolymer,SBS)改性沥青混合料自愈合性能的影响,采用了半圆弯曲试验对SBS改性沥青混合料进行断裂—愈合—再断裂效果研究,愈合期间对SBS改性沥青混合料采用了烘箱加热、微波加热和微波—烘箱联合加热3种方式,并将沥青试件愈合前后断裂时最大压力比作为评价自愈合能力的指标,研究了沥青混合料在不同加热方式下的自愈合能力影响规律。研究表明:改性沥青混合料使用微波—烘箱联合加热的自愈合能力最好,烘箱加热愈合效果最差;改性沥青混合料在微波和烘箱的加热过程随着温度的升高,愈合效果和速率也在持续升高,当温度超过沥青软化点后,愈合效果继续增加,愈合速率表现出下降趋势。

In order to study the influence of various heating methods on the self-healing performance of styrene-butadiene-styrene block copolymer(SBS)modified asphalt mixture,the semi-circular bending test was used to study the fracture-healing-refracture effect of SBS modified asphalt mixture.During the healing period,the SBS modified asphalt mixture was heated by oven heating,microwave heating and microwave-oven combined heating.The ratio of the maximum pressure at the fracture of the asphalt specimen before and after healing was used as an index to evaluate the self-healing ability.The influence of self-healing ability of asphalt mixture under different heating methods was studied.The results show that the self-healing ability of asphalt mixture using microwave-oven combined heating is the best,and the healing effect of oven heating is the worst.The healing effect and rate also continue to increase with the temperature of asphalt mixture increasing.When the temperature exceeds the softening point of asphalt,the healing effect continues to increase,the healing rate shows a downward trend.