Effects of ground granulated blastfurnace slag (GGBS) on the swelling properties of lime-stabilized sulfate-bearing soils
Effects of ground granulated blastfurnace slag (GGBS) on the swelling properties of lime-stabilized sulfate-bearing soils
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DOI：
10.1016/j.enggeo.2013.05.016
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发表时间：
2013-08-19
影响因子：
7.4
通讯作者：
Nalbantoglu, Zalihe
中科院分区：
文献类型：
--
作者：
Celik, Ece;Nalbantoglu, Zalihe
在含硫酸盐的粘土中使用钙基稳定剂，如氧化钙（石灰），由于钙矾石的形成，历史上造成了结构上的破坏，钙矾石是一种膨胀的矿物，在粘土组分中存在硫酸盐、钙和铝化合物时形成。本文研究了工业副产物矿渣（GGBS）对含硫酸盐土壤稳定性的影响。首先对添加不同浓度硫酸盐的石灰处理膨胀土进行了实验室试验，然后对添加相同浓度硫酸盐但添加6%矿渣的石灰处理膨胀土进行了相同的试验。研究中使用了三种不同的硫酸盐浓度（2000、5000和10,000 ppm），并研究了压实关系、阿特伯格极限、线性收缩和膨胀势。试验结果表明，在硫酸盐浓度为5000 ppm和10000 ppm时，土壤中硫酸盐的存在导致石灰处理土壤的塑性和膨胀势异常增加。硫酸盐浓度为1万ppm的石灰处理土壤的膨胀势比自然土壤高出3倍。这种高膨胀势土壤的扫描电子显微照片证实了钙辉石矿物的生长。另一方面，试验结果表明，石灰和GGBS在稳定含硫酸盐粘土中使用，显著改善了粘土的塑性和膨胀势。在石灰处理过的土壤中加入6%的矿渣，消除了土壤中硫酸盐的有害影响。当矿渣含量为6%时，硫酸盐浓度为10000 ppm的石灰处理土的膨胀势由8%下降到1%，而硫酸盐浓度为5000 ppm的石灰处理土则没有膨胀。(c) 2013 Elsevier B.V.版权所有
The use of calcium-based stabilizers such as calcium oxide (lime) in sulfate-bearing clay soils has historically caused structural distress due to the formation of ettringite, an expansive mineral which develops in the presence of sulfate, calcium, and aluminum compounds of clay fraction. In this work, a research was conducted to study the effectiveness of ground granulated blastfurnace slag (GGBS), an industrial by-product, for providing better stabilization of sulfate bearing soils. Laboratory tests were first performed on the lime-treated expansive soil containing different concentrations of added sulfate and then the same tests were repeated on the lime-treated soil, containing the same concentration of sulfate but this time adding 6% slag. Three different sulfate concentrations (2000, 5000, and 10,000 ppm) were used in the study and the compaction relationships, Atterberg limits, linear shrinkage and swell potentials were investigated. Test results indicated that the presence of sulfate in the soil resulted in abnormal increase in the plasticity and the swell potential of the lime-treated soil with 5000 and 10,000 ppm sulfate concentrations. The swell potential of the lime-treated soil with 10,000 ppm sulfate concentration became three times higher than that of the natural soil. The scanning electron micrograph of this higher swell potential soil confirmed the growth of the ettringite minerals. On the other hand, test results indicated that the use of lime with GGBS in stabilizing sulfate bearing clays produced significant improvements in the plasticity as well as the swell potential. Addition of 6% slag into the lime treated soil eliminated the harmful effect of sulfate in the soils. In the presence of 6% slag, the swell potential of the lime-treated soil with 10,000 ppm sulfate concentration decreased from 8% to 1%, whereas the lime-treated soil with 5000 ppm sulfate concentration showed no swelling. (c) 2013 Elsevier B.V. All rights reserved.