基于沥青中蜡析出的流变性分析  

Rheological Property Analysis Based on Wax Precipitation in Asphalt

作　　者：金志强 Jin Zhiqiang(China Railway Third Engineering Group Third Engineering Co.,Ltd.,Taiyuan 030006,China)

机构地区：[1]中铁三局集团第三工程有限公司,山西太原030006

出　　处：《市政技术》2023年第9期39-45,共7页Journal of Municipal Technology

摘　　要：为了探究沥青中蜡析出的具体过程和降温速率、沥青老化、乙烯-醋酸乙烯酯共聚物对蜡析出的影响,选用了8种SHRP沥青,并分别对AAV和AAC进行了PAV老化和3%的EAV改性,通过动态剪切流变试验得到了沥青的黏温曲线,利用黏性流动活化能法精确地拟合出了沥青的蜡析出温度。研究结果表明:沥青的析蜡点温度随着沥青中蜡含量的增加而增高。当沥青中蜡结晶析出,沥青的黏度急剧增大,沥青的流变性变差;随着降温速率的降低,沥青的析蜡点温度增高;沥青老化使沥青中轻质组分减少,重质组分增多,增高了沥青的析蜡点温度;相比基质沥青,乙烯-醋酸乙烯酯共聚物的黏度增加,析蜡点温度降低,沥青的流变性得到了改善。In order to investigate the specific process of wax precipitation in asphalt,the cooling rate,asphalt aging,and the impact of ethylene-vinyl acetate copolymer on wax precipitation,eight types of SHRP asphalt were selected to conduct PAV aging and 3%EAV modification were conducted on AAV and AAC,respectively.Dynamic shear rheological tests were performed to obtain the asphalt’s viscosity-temperature curves,and the wax precipitation temperature was accurately determined by the activation energy method for viscous flow.The research reveals that the wax precipitation temperature of the asphalt increases with increase of wax content in the asphalt.When wax crystallizes and precipitates in the asphalt,its viscosity increases sharply and rheological properties deteriorates;With the cooling rate decrease,the wax precipitation temperature rises;Asphalt aging reduces the light components and increases the heavy components,which elevated the wax precipitation temperature;Compared with the base asphalt,the ethylene-vinyl acetate copolymer exhibits higher viscosity,lower wax precipitation temperature,and improved rheological properties for the asphalt.

关 键 词：沥青 流变性 蜡析出 析蜡点温度 黏温曲线 沥青老化 乙烯-醋酸乙烯酯共聚物 

分 类 号：U414[交通运输工程—道路与铁道工程]