Effect of Drying‐Wetting Cycles on Engineering Properties of Expansive Soils Modified by Industrial Wastes

Abstract

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.

Study on Crack Development and Micro-Pore Mechanism of Expansive Soil Improved by Coal Gangue under Drying–Wetting Cycles

“…Some scholars have improved the expansive soil with other materials (such as slag, fly ash, and lime) to reduce its cracks. The final results show the effectiveness of these methods [ 23 , 24 , 25 ]. Coal gangue contains more mineral components, such as low hydrophilic kaolinite and illite.…”

“…An appropriate amount of lignin can be filled in the soil pores to make the soil particles more closely connected, so as to improve the stability of expansive soil. Chu et al [ 24 ] studied the effects of drying–wetting cycles on the expansion behavior and compressibility of iron tailing sand and calcium carbide slag-modified expansive soil. The micro-pore structure of soil samples was analyzed by the mercury injection method.…”

Contemplated Investigation and Statistical Prediction of the Swelling Potential of Expansive Soils Using Index Properties of Holte Town, Southern Ethiopia

“…Whereas the study area falls under inorganic clays of high plastic clay soil except the test pits TP10 and TP11, which is inorganic silt (MH) as per Unified Soil Classification System. In which all test pits having liquid limits values more than fifty revealed that the soils in the area are presented by high plasticity and expansiveness, which are fulfilling the requirements of the specified practices of expansive properties [31].…”

Failure Mechanisms and Protection Measures for Expansive Soil Slopes: A Review

“…The effectiveness of expansive soil modification materials under adverse environmental influences, such as wet-dry cycles and freeze-thaw cycles, should also be considered. Mixtures of octadecyl trimethyl ammonium chloride and Potassium chloride, iron tailing sand and calcium carbide slag, polypropylene fiber and silica fume, and nano-silica and electric arc furnace slag still exhibit good modification effects of expansive soil after wet-dry or freeze-thaw cycles [167][168][169][170].…”