摘要
为研究水泥-纤维复合材料改良路基粉质黏土干湿循环力学特性,室内展开了改性土的力学试验及微观电镜扫描试验。研究发现:在粉质黏土中掺入水泥能够大幅提升其力学强度,掺入3%水泥后,粉质黏土试样的强度可以提升约5倍,掺入聚丙烯纤维对粉质黏土试样的强度贡献不大,但可以显著提升粉质黏土的塑性变形能力;水泥-纤维改性粉质黏土峰值应力对应的应变大概在3%~4%,并表现出很好的塑性变形特性,峰后应力下降缓慢,这主要得益于纤维的抗拉拔作用;抗压强度随干湿循环次数增加而逐渐减小,经历10次、20次、30次干湿循环后,改性粉质黏土单轴抗压强度试验分别较未经历干湿循环的试样降低40.18%、54.60%和74.55%。研究成果为我国软土地基加固提供一定的指导。
In order to study the dry-wet cyclic mechanical properties of cement-fiber composite modified subgrade silty clay, the mechanical tests and micro-electron microscope scanning tests of the modified soil were carried out in the laboratory. It is found that the mechanical strength of silty clay can be greatly improved by adding cement. After adding 3% cement, the strength of silty clay sample can be increased by about 5 times. Adding polypropylene fiber has little contribution to the strength of silty clay sample, but it can significantly improve the plastic deformation ability of silty clay;The strain corresponding to the peak stress of cement-fiber modified silty clay is about 3%~4%, and shows good plastic deformation characteristics.The post-peak stress decreases slowly, which is mainly due to the anti-pulling effect of fiber;The compressive strength decreases gradually with the increase of dry-wet cycles. After 10, 20 and 30 dry-wet cycles, the uniaxial compressive strength of modified silty clay is 40.18%, 54.60% and 74.55% lower than that of the sample without dry-wet cycles, respectively. The research results provide some guidance for the reinforcement of soft soil foundation in China.
作者
戴元晗
Dai Yuanhan(CCCC First Highway Consultants Co.,Ltd.,Xi'an,China)
出处
《科学技术创新》
2023年第3期141-144,共4页
Scientific and Technological Innovation
关键词
水泥
聚丙烯纤维
改性粉质黏土
干湿循环
微观电镜扫描
cement
polypropylene fiber
modified powdered clay
wet and dry cycles
microscopic electron microscopy scanning
