摘要
为了探究水泥改良砂土在冻融条件下的力学特性,选取北方季冻区常见的砂土为研究对象,通过无侧限抗压强度实验和冻融循环实验,分析了水泥掺量、龄期和冻融循环次数对水泥改良砂土强度及抗冻性能的影响.结果表明:随着水泥掺量的增加,水泥改良砂土的无侧限抗压强度有所提高;水泥掺量越大,水泥改良砂土在高龄期下的强度增长率越高;随着循环次数的增加,水泥改良砂土的质量损失率呈先增加后减小的趋势;随着循环次数的增加,水泥改良砂土的抗压强度呈曲线趋势减小,并且在到达一定循环次数后其强度基本保持不变;冻融循环会使水泥改良砂土的峰值应力不断减小,但其到达峰值应力时的应变基本没有变化;综合考虑各项指标,建议采用14%~17%的水泥掺量进行季冻区路基的设计和施工。
In order to explore the mechanical properties of cement improved sand under freeze-thaw condition,the common sand in northern seasonal frozen area is selected as the research object,and the effects of cement content,age and freeze-thaw cycles on the strength and frost resistance of cement improved sand are analyzed through unconfined compressive strength test and freeze-thaw cycle test.The results show that the unconfined compressive strength of cement modified sand increases with the increase of cement content;The larger the cement content is,the higher the strength growth rate of cement modified sand is at the advanced age;With the increase of the number of cycles,the mass loss rate of cement modified sand increases first and then decreases;With the increase of the number of cycles,the compressive strength of cement modified sand decreases in a curvilinear trend,and remains unchanged after a certain number of cycles;The freeze-thaw cycle can make the peak stress of cement modified sand decrease continuously,but the strain when it reaches the peak stress basically does not change;Considering all the indexes,it is suggested that 14%~17%cement should be used in the design and construction of Subgrade in seasonal frozen area.
作者
冯冬冬
FENG Dong-dong(China Railway 18th Bureau Group No.5 Engineering Co.,Ltd.,Tianjin Binhai New Area 300000)
出处
《河北建筑工程学院学报》
CAS
2021年第1期37-42,49,共7页
Journal of Hebei Institute of Architecture and Civil Engineering
关键词
水泥改良土
冻融循环
龄期
强度变形特性
cement improved soil
freeze-thaw cycle
age
strength deformation characteristics
