摘要
为了研究复合纤维沥青混合料在高温持续荷载作用下的稳定性,根据工程中常用纤维和已有研究成果,选用了三种复合纤维,对沥青混合料的变形发展规律及内部空隙结构特征开展试验研究。首先采用加速加载试验,对不掺加纤维和掺加复合纤维的沥青混合料在高温持续荷载作用下的横断面变化和车辙深度进行分析;再利用X-CT扫描技术与VG软件三维重构功能,研究不同纤维沥青混合料的空隙组成及形态特征演变规律。结果表明:高温持续荷载作用下,掺加纤维混合料横断面变形呈现"W"字型,不同纤维在沥青混合料中发挥"加筋"、"增黏"、"吸油"的协同作用,能显著减小沥青混合料的流动变形,且掺加复合纤维III的混合料流动变形最小;掺加不同复合纤维的沥青混合料可采用y=a-b·ln(x+c)进行车辙深度预估。加速加载试验后,掺加三种复合纤维的沥青混合料空隙率最大仅增加7%,分形维数仅降低不到0.5%,表明掺加三种复合纤维基本不改变沥青混合料的空隙结构特征,而且在高温持续荷载作用下,可较好地保持沥青混合料内部空隙的三维形态特征,进而改善沥青混合料的抗变形能力。
In order to study the stability of the hybrid fiber asphalt mixture under high temperature and continu- ous loading, three kinds of hybrid fiber were selected according to the commonly used fiber and existing research re- sults, and the deformation development and characteristics of internal void structure were experimentally carried out. Firstly, the accelerated loading test was carried out on the mixture of no fiber and three kinds of hybrid fiber under high temperature and continuous loading, cross sectional variation and rutting depth records of different load- ing times were studied- then the different hybrid fiber mixture void gradation and evolution of void morphology were studied using X-CT scanning technology and three-dimensional reconstruction function of VG software. The results indicate that under high temperature and continuous loading, cross section deformation of hybrid fiber asphalt mix- ture presents the ＂W＂ shape, the different fiber in the mixture plays a ＂reinforcement＂, ＂thickening＂, ＂absorbing oil＂ synergistic effect, the flow deformation of asphalt mixture can be significantly reduced, the flow deformation of the hybrid fiber m mixture is the smallest and y=a--b, ln（x＋c） can be used to predict the rutting depth of asphalt mixture with different hybrid fibers. After the accelerated loading test, the porosity of the three hybrid fiber increa- ses by only 7%, and the fractal coefficient only decreases by less than 0.5%. Research shows that adding three kinds of hybrid fiber can not change the characteristics of void structure, and under high temperature and continuous loading, the three-dimensional shape characteristics of the internal voids of asphalt mixture can be kept well, in or- der to improve the anti deformation ability of asphalt mixture.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2017年第10期2344-2355,共12页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(51478046
51408050)
关键词
道路工程
复合纤维沥青混合料
加速加载试验
X-CT扫描
高温稳定性
空隙结构
road engineering
hybrid fiber asphalt mixture
accelerated loading test
X-CT scanning
high temper-ature stability
void structure
