纳米Al_(2)O_(3)改良滨海水泥土的动力特性及微观机理试验研究  

Dynamic characteristics and micro-mechanisms of coastal cement soil modified by nano-Al_(2)O_(3)

作　　者：庄心善 杨本驰 陶高梁 ZHUANG Xinshan;YANG Benchi;TAO Gaoliang(School of Civil Engineering Architecture and Environment,Hubei University of Technology,Wuhan 430068,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,湖北武汉430068

出　　处：《浙江大学学报（工学版）》2024年第7期1457-1466,共10页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51708190)。

摘　　要：在循环荷载及腐蚀环境下进行动三轴、扫描电镜、核磁共振等试验,分析纳米Al_(2)O_(3)改良滨海水泥土的动应力–应变、动弹性模量、阻尼比及微观孔隙变化.试验结果表明:动应变随动应力增大而增加,动弹性模量随动应力增大而减小;加载频率增大使动应变减小,使动弹性模量增加;海盐的质量分数增大使动应变增大,使动弹性模量减小.纳米Al_(2)O_(3)改良水泥土的阻尼比-动应变曲线随着加载频率的增加逐渐下移,该曲线在不同加载频率下均出现交汇点,交汇点随着海盐的质量分数增大向右移动.相比素水泥土,纳米Al2O3改良水泥土的孔隙弛豫时间分布曲线主峰峰值及峰面积显著缩小,土孔隙中有C-S-H、C-A-H凝胶物质胶结填充,形成空间网状结构,胶结效果显著.纳米Al_(2)O_(3)改良水泥土在海盐质量分数小的情况下孔隙明显减少,且孔隙率比素水泥土的更低.Dynamic triaxial,SEM,NMR and other tests were carried out under cyclic loading and corrosive environment to analyze the dynamic stress-strain,dynamic elastic modulus,damping ratio and microscopic pore changes in nano-Al_(2)O_(3) modified coastal cement soil.Test results show that the dynamic strain increases with the increase of dynamic stress,and the dynamic elastic modulus decreases with the increase of dynamic stress.The increase in loading frequency makes the dynamic strain decrease and the dynamic elastic modulus increase.The increase in the mass fraction of set salt makes the dynamic strain increase and the dynamic elastic modulus decrease.The damping ratio-dynamic strain curve of nano-Al_(2)O_(3) modified cement soil gradually moves down with the increase of loading frequency,and the intersection point of the curves appears at different loading frequencies,and the intersection point moves to the right with the increase of the mass fraction of set salt.The peak value and peak area of the main peak of the relaxation time distribution curve of the nano-Al_(2)O_(3) modified cement soil were significantly lower than those of the pure cement soil,and the C-S-H and C-A-H gel substances were cemented in the soil pores to form a spatial network structure,and the cementation effect was significant.Nano-Al_(2)O_(3) modified cement soil showed a significant reduction in porosity at small sea salt mass fractions and exhibited lower porosity compared to the pure cement soil.

关 键 词：纳米Al_(2)O_(3) 水泥土 循环荷载 腐蚀环境 微观结构 

分 类 号：TU411[建筑科学—岩土工程]