The swelling properties of expansive soils can be reduced by the addition of modifiers. Nevertheless, the performance deterioration after modification occurs when weathering for a long term. Therefore, in this study, the effect of drying-wetting cycles on swelling behaviour and compressibility of modified expansive soils with the iron tailing sand and calcium carbide slag has been investigated. The swelling potential initially increases and subsequently decreases with the increasing number of cycles, reaches the peak at the seventh cycle, and tends to equilibrium after the tenth cycle. These results show that drying-wetting cycles will destroy the soil structure. The compressibility of modified expansive soils increases with the drying-wetting cycles, where an empirical formula between compressibility and the cycle number was established. Microstructural analysis is performed using mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). The results of microstructural analysis show a tendency of degradation process.

中文翻译：

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干湿循环对工业废弃物改性膨胀土工程特性的影响

膨胀土的膨胀特性可以通过添加改性剂来降低。然而，长期风化时，改性后的性能会下降。因此，在这项研究中，研究了干湿循环对铁尾矿砂和电石渣改性膨胀土膨胀特性和可压缩性的影响。溶胀电位最初随着循环次数的增加而增加，然后降低，在第七个循环达到峰值，并在第十个循环后趋于平衡。这些结果表明，干湿循环将破坏土壤结构。改性膨胀土的可压缩性随干湿循环而增加，建立了可压缩性与循环次数之间的经验公式。使用水银压入孔隙率法（MIP）和扫描电子显微镜（SEM）进行微结构分析。显微组织分析的结果显示出降解过程的趋势。