Abstract

In this study, fly ash was used as an additive to increase the dewatering efficiency of an excavated soil slurry treated by electro-osmosis combined with mechanical pressure and thus effectively obtain a low-moisture treated slurry with wider applicability; the properties of the treated slurry were also studied. The results showed that, at a fly ash dosage of 5%, the drainage volume was 350 mL, which presented significantly better dewaterability properties than the unconditioned slurry, the water content of the anode and cathode layer after treated was 20.5% and 19.1%, the compressibility coefficient was 0.170 MPa⁻¹ and 0.152 MPa⁻¹, and the shear strength was 81.2 kPa and 85.1 kPa, respectively. And we also studied the physical properties of the treated slurry at different locations, the physical properties were also affected by the fly ash dosage. It was concluded that fly ash used in adequate concentrations can reduce the slurry water content, and fly ash also can improve the mechanical properties of excavated soil slurry after the mechanical dewatering combined with electro-osmosis.

摘要

本研究以粉煤灰为添加剂，提高电渗结合机械压力处理的开挖土浆的脱水效率，从而有效地获得适用性更广的低水分处理土浆；还研究了处理过的浆料的性质。结果表明，在粉煤灰用量为 5% 时，排水量为 350 mL，其脱水性能明显优于未处理的浆料，处理后的正负极层含水量分别为 20.5% 和 19.1%，压缩系数为0.170 MPa ^-1和0.152 MPa ^-1, 剪切强度分别为 81.2 kPa 和 85.1 kPa。并且我们还研究了不同位置处理后的浆料的物理性质，这些物理性质也受到粉煤灰用量的影响。得出的结论是，使用适当浓度的粉煤灰可以降低泥浆含水量，粉煤灰还可以改善机械脱水结合电渗后开挖土浆的力学性能。