基于湿陷性黄土-红砂岩集成流态固化土抗冻性试验研究
Experimental Study on Frost Resistance of Fluidized Solidifiable Soil Integrated by Collapsible Loess and Red Sandstone
朱彦鹏 1吕玉宝 1房光文 1王浩 1张志琦1
作者信息
- 1. 兰州理工大学土木工程学院,兰州理工大学西部土木工程防灾减灾教育部工程研究中心,兰州 730050
- 折叠
摘要
冻融循环作用是造成土体力学性能损伤的重要因素之一.为研究冻融循环作用下湿陷性黄土-红砂岩集成流态固化土的强度特性,采用室内试验的方法对不同冻融循环次数下的流态固化土进行力学试验和电镜扫描试验,分析在冻融循环作用下不同配比的流态固化土物理力学参数的变化规律及能量耗散机理.结果表明:红砂岩掺量、含水率和水泥掺量随冻融循环次数增加,对抗压强度的影响程度不同,掺入红砂岩可有效提高流态固化土的抗压强度;抗压强度与冻融循环次数的关系符合递减型指数函数关系;弹性模量、质量、黏聚力、内摩擦角及应变能密度等主要力学指标则随红砂岩掺量和冻融循环次数的增加,呈不同的降低规律;结合电镜扫描结果分析了冻融损伤后流态固化土微观结构的变化规律,指出冻融循环作用可改变由红砂岩颗粒构建的骨架结构,阐明了冻融循环作用下流态固化土能量耗散的机理.
Abstract
Freeze-thaw cycles are one of the important factors causing mechanical damage of soil.To study the strength characteristics of fluidized solidifiable soil integrated by collapsible loess and red sandstone ex-perienced freeze-thaw cycles,mechanical and scanning electron microscope tests were conducted on the flu-idized solidifiable soil experienced different rounds of freeze-thaw cycles by indoor tests,and the variable regularities of physical and mechanical parameters and energy dissipation mechanisms of the fluidized solid-ifiable soil with different mix proportions experienced freeze-thaw cycles were analyzed.The results indica-ted that the red sandstone content,water content and cement content increased with the rounds of freeze-thaw cycles and had different effects on compressive strength.To mix red sandstone could effectively im-prove the compressive strength of fluidized solidifiable soil.The relation between compressive strength and the rounds of freeze-thaw cycles complied with a decreasing exponential function relation.The main me-chanical indexes,including elastic moduli,masses,cohesion,internal friction angles and strain energy densities,decreased with the increase in the red sandstone content and the rounds of freeze-thaw cycles.Combining with the results by SEM,the variable regularity of microstructure of fluidized solidifiable soil damage by freeze-thaw cycles was analyzed.That freeze-thaw cycles could change the microstructure con-structed by red sandstone particles was pointed out,and thus the mechanism of energy dissipation of fluid-ized solidifiable soil experienced freeze-thaw cycles was clarified.
关键词
预拌流态固化土/湿陷性黄土/红砂岩/冻融循环作用/力学性质/微观结构Key words
pre-mixed fluidized solidifiable soil/collapsible loess/red sandstone/freeze-thaw cycle/me-chanical property/microstructure引用本文复制引用
出版年
2024
NETL
NSTL
万方数据