摘要
为了研究养护温度对水泥土力学性能的影响,对水泥掺入比为0.2,养护龄期为7,14,28,60和90 d,养护温度为5,20,40和60℃的水泥土试样进行无侧限抗压强度试验,获得相应的应力-应变全过程曲线、无侧限抗压强度和变形模量E50,并根据试验结果分析不同温度下水泥土无侧限抗压强度和变形模量E50随龄期变化规律。基于化学反应动力学中质量作用定理推导出无侧限抗压强度演化方程为指数函数形式,并据此通过回归分析分别建立考虑温度影响的无侧限抗压强度和变形模量E50的演化方程。探讨了无侧限抗压强度与变形模量E50之间的关系。研究结果表明:水泥土应力-应变全过程曲线表现出明显应变软化特征,峰值应力随养护温度增加而增长,峰值应变受温度影响较小,基本在1%~2%之间。无侧限抗压强度随养护龄期增加而增长,养护温度越高其增长速度越快;无侧限抗压强度随养护温度增加呈非线性增长,当养护温度从40℃提高到60℃时,强度增幅最大。无侧限抗压强度和变形模量E50随龄期的演化规律基本相同,建立的演化方程与试验数据吻合较好。无侧限抗压强度和变形模量E50两者基本呈线性关系。研究成果可为工程设计提供参考。
In order to study the effect of curing temperature on the mechanical properties of cement soil. Firstly,unconfined compression tests were carried out on cement soil samples with cement mixing ratio of 0.2, curing age of 7, 14, 28, 60 and 90 days, curing temperature of 5, 20, 40 and 60 ℃.The corresponding complete stressstrain process curve, unconfined compressive strength and deformation modulus E50 of cement soil were obtained.Then, analyzing the variation law of unconfined compressive strength and deformation modulus E50 of cement soil with age at different temperatures according to the test results. Next, based on the mass action theorem in chemical reaction kinetics, the evolution equation of unconfined compressive strength was deduced in the form of exponential function, and the evolution equations of unconfined compressive strength and deformation modulus E50 considering the influence of temperature were established through regression analysis. Finally, the relationship between unconfined compressive strength and deformation modulus E50 was discussed. The results show that the complete stress-strain process curve of cement soil shows obvious strain softening characteristics. The peak stress increases with the increase of curing temperature, and the peak strain is less affected by temperature, which is basically between 1%~2%. The unconfined compressive strength increases with the increase of curing age, and the higher the curing temperature, the faster the growth rate of cement soil strength. The unconfined compressive strength increases nonlinearly with the increase of curing temperature. When the curing temperature raise from 40 ℃ to 60 ℃, the increase of strength is the largest. The evolution law of deformation modulus E50 and unconfined compressive strength with age are basically the same and the established evolution equations are in good agreement with the experimental data. The relationship between deformation modulus E50 and unconfined compressive strength is basically linear. The research res
作者
陈昌富
韦思琦
蔡焕
CHEN Changfu;WEI Siqi;CAI Huan(Key Laboratory of Building Safety and Energy Efficiency of Ministry of Education,Hunan University,Changsha 410082,China;College of Civil Engineering,Hunan University,Changsha 410082,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2023年第1期190-199,共10页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51978254)
长沙市科技资助项目(kq2004013)。
关键词
水泥土
养护温度
应力-应变曲线
无侧限抗压强度
变形模量
演化方程
cement soil
curing temperature
stress-strain curve
unconfined compressive strength
deformation modulus
evolution equation
