Effects of Long-Term Repeated Freeze-Thaw Cycles on the Engineering Properties of Compound Solidified/Stabilized Pb-Contaminated Soil: Deterioration Characteristics and Mechanisms
Effects of Long-Term Repeated Freeze-Thaw Cycles on the Engineering Properties of Compound Solidified/Stabilized Pb-Contaminated Soil: Deterioration Characteristics and Mechanisms
复制标题
长期反复冻融循环对复合固化/稳定铅污染土工程性能的影响：劣化特征及机理
DOI：
10.3390/ijerph17051798
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发表时间：
2020-03
影响因子：
--
通讯作者：
Liu Xinrong
中科院分区：
文献类型：
--
作者：
Yang Zhongping;Li Xuyong;Li Denghua;Wang Yao;Liu Xinrong
在各种室内试验中，研究了长期反复冻融循环和污染水平对铅污染土壤工程性质（q（u），E-50，phi，c和k）的影响。这些土壤固化/稳定（S/S）与三种类型的水泥基组合粘合剂（C2.5S5F5，C5S2.5F2.5，和C5 S5，水泥，石灰，粉煤灰，混合在不同的比例;这些材料被广泛用于S/S技术）。通过测定铅污染土的无侧限抗压强度、直剪强度和渗透系数，确定了复合固化/稳定铅污染土（Pb-CSCS）的强度和渗透系数。通过CT扫描、扫描电镜（SEM）和傅里叶变换红外光谱（FTIR）分析了不同冻融次数下的老化机理。结果表明，在反复冻融循环过程中，Pb-CSCS的工程性能均有不同程度的降解，但在冻融循环30 d后降解趋于稳定。研究还发现，污染物阻碍了土壤结构内的水合作用和其他有利反应（如离子交换和凝聚以及火山灰反应）。水化反应的激活和冻融循环引起的土颗粒重排，从而引起工程性质的波动，并表现出不同的退化特性与Pb 2+含量的变化。
The effects of long-term repeated freeze-thaw cycles and pollution levels on the engineering properties (q(u), E-50, phi, c, and k) of Pb-contaminated soils were investigated in various laboratory tests. These soils were solidified/stabilized (S/S) with three types of cement-based combined binders (C2.5S5F5, C5S2.5F2.5, and C5S5, cement, lime, and fly ash, mixed in different proportions; these materials are widely used in S/S technology). The strength and permeability coefficient of compound solidified/stabilized Pb-contaminated soils (Pb-CSCSs) were determined based on measurements of unconfined compressive strength (UCS), direct shear, and permeability. CT scanning, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) tests were employed to analyse the deterioration mechanisms under various repetitions of freeze-thaw cycles. The results showed that, under repeated freeze-thaw cycles, the engineering properties of Pb-CSCSs all degraded to varying degrees, though degradation tended to stabilise after 30 days of freeze-thaw cycles. The study also found that the pollutants obstruct hydration and other favourable reactions within the soil structure (such as ion exchanges and agglomerations and pozzolanic reactions). The activation of hydration reactions and the rearrangement of soil particles by freeze-thaw cycles thus caused the engineering properties to fluctuate, and soils exhibited different deterioration characteristics with changes in Pb2+ content.
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DOI：
10.1080/15320383.2014.890168
发表时间：
2014-03
期刊：
Soil and Sediment Contamination: An International Journal
影响因子：
--
作者：
Y. Xi;Xiaofeng Wu;Hao Xiong
通讯作者：
Y. Xi;Xiaofeng Wu;Hao Xiong
DOI：
10.1061/9780784480434.045
发表时间：
2017-03
期刊：
--
影响因子：
--
作者：
H. L. Wu;Y. Du;Fei Wang;M. Wei;Y. Feng
通讯作者：
H. L. Wu;Y. Du;Fei Wang;M. Wei;Y. Feng
影响因子：
1.5
作者：
Du Yanjun;Jing Fei;Liu Songyu;Chen Lei;Z. Fan
通讯作者：
Du Yanjun;Jing Fei;Liu Songyu;Chen Lei;Z. Fan
DOI：
10.1504/ijep.2016.10000740
发表时间：
2016-10
影响因子：
0.7
作者：
Meng Zhou;Hao-liang Wu;Yan-jun Du;Yucheng Yi
通讯作者：
Meng Zhou;Hao-liang Wu;Yan-jun Du;Yucheng Yi
DOI：
10.3964/j.issn.1000-0593(2017)03-0743-06
发表时间：
2017-03-01
影响因子：
0.7
作者：
Yang, Gang;Li, Hui;Gu, Heng-xing
通讯作者：
Gu, Heng-xing