摘要
为促进红黏土分布地区道路建设,进一步解决二灰稳定红黏土存在的脆性破坏和收缩开裂等问题,研究采用掺入0.15%、0.30%、0.45%、0.60%的聚丙烯纤维加固二灰稳定红黏土,并通过击实试验、无侧限抗压强度试验、抗弯拉强度试验、温缩特性试验以及干缩特性试验,分析聚丙烯纤维加固二灰稳定红黏土的力学与收缩性能与养护龄期和纤维掺量的关系。试验结果表明:虽然聚丙烯纤维对二灰稳定红黏土早期的抗压强度、抗弯拉强度以及温缩和干缩系数的改善效果并不明显,但随着养护龄期的增加,聚丙烯纤维加固二灰稳定红黏土的后期抗压强度和抗弯拉强度得到较大提高,破坏韧性得到提升,温缩系数和干缩系数与未掺加聚丙烯纤维的材料相比显著减小。综合考虑试验结果及经济性,在二灰稳定红黏土中掺加0.45%的聚丙烯纤维能够有效改善二灰稳定红黏土的土体强度,提升抗变形能力,抑制收缩开裂,使其满足公路基层的技术要求。
In order to promote the road construction in the red clay distribution area,further solve the problems of brittle failure and shrinkage cracking in the lime&fly ash stabilized laterite.The lime&fly ash stabilized red clay is reinforced with 0.15%,0.30%,0.45%and 0.60%the polypropylene fiber,and the compaction test,unconfined compressive strength test,bending strength test,temperature shrinkage test and dry shrinkage test are carried out to analyze the relationship between the mechanical and shrinkage properties of polypropylene fiber reinforced lime and fly ash stabilized red clay and the curing age and fiber content.The experimental results show that although the polypropylene fiber has no obvious effect on the early compressive strength,bending strength and temperature shrinkage and shrinkage coefficient of the lime&fly ash stabilized red clay,the polypropylene fiber increases with the curing age.The compressive strength and bending strength of the reinforced lime&fly ash stabilized red clay are greatly improved,and the fracture toughness is improved.The temperature shrinkage coefficient and the dry shrinkage coefficient are significantly reduced compared with the materials not participating in the polypropylene fiber.Considering the experimental results and economy,adding 0.45%to the two-ash stable red clay can effectively improve the soil strength of the lime&fly ash stabilized red clay,improve the resistance to deformation,and inhibit the shrinkage cracking,so that it can meet the technology requirement of the road base course.
作者
肖庆一
张恒
孙立东
封仕杰
XIAO Qing-yi;ZHANG Heng;SUN Li-dong;FENG Shi-jie(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China)
出处
《公路》
北大核心
2020年第8期306-312,共7页
Highway
基金
天津市科技计划项目,项目编号16ZXCXSF00110。
关键词
道路工程
聚丙烯纤维
二灰红黏土
力学性能
收缩性
road engineering
polypropylene fiber
lime&fly ash stabilized red clay
mechanical properties
shrinkage properties
