Abstract Application of the flocculation-solidification combined method (FSCM) for building a surface working platform is a reasonable option to resolve the personnel and equipment accessibility problem at a dumping site filled with dredged mud slurry at extra high water content (EHW-MS). In the originally proposed FSCM, the solidification component admixed is mainly cement, which tends to show some limitations under unfavourable conditions. This study focuses on discussing the rationality of an optimization measure, i.e., replacing a portion of cement by metakaolin in FSCM. 17 sets of laboratory experiments are performed to identify the influence of main factors on the strength behaviour of EHW-MS treated jointly by cement, metakaolin and flocculant (C-M-F treated EHW-MS). The microstructure and solidification mechanism of C-M-F treated EHW-MS are also analysed based on the X-ray diffraction spectrums and the field emission scanning electron microscopy images. Results indicate that replacing an appropriate portion of cement by metakaolin is a technically reasonable option to enhance the holistic performance of FSCM in EHW-MS treatment, and there is an optimal replacement ratio, beyond which the holistic performance of FSCM is likely to be discounted. When a portion of cement is replaced by metakaolin, the efficiency of flocculant at a given dosage tends to be degraded, and in this situation, increasing the flocculant dosage is a feasible measure to further improve the performance of FSCM. However, the flocculant dosage should not exceed a critical value, otherwise the strength gain tends to be hampered.

中文翻译：

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水泥、偏高岭土和絮凝剂联合处理疏浚泥浆的强度行为

摘要 应用絮凝-凝固联合法（FSCM）搭建地面工作平台是解决超高含水量疏浚泥浆（EHW-MS）倾倒场人员和设备可达性问题的合理选择。在最初提出的 FSCM 中，掺入的固化组分主要是水泥，在不利条件下往往表现出一定的局限性。本研究重点讨论优化措施的合理性，即在 FSCM 中用偏高岭土代替一部分水泥。进行了 17 组实验室实验，以确定主要因素对水泥、偏高岭土和絮凝剂联合处理的 EHW-MS（CMF 处理的 EHW-MS）强度行为的影响。还基于 X 射线衍射光谱和场发射扫描电子显微镜图像分析了 CMF 处理的 EHW-MS 的微观结构和凝固机制。结果表明，用偏高岭土替代适当比例的水泥是提高 FSCM 在 EHW-MS 处理中整体性能的技术上合理的选择，并且存在最佳替代比例，超出该比例可能会降低 FSCM 的整体性能。当一部分水泥被偏高岭土替代时，在给定剂量下絮凝剂的效率趋于下降，在这种情况下，增加絮凝剂剂量是进一步提高FSCM性能的可行措施。但絮凝剂的用量不应超过临界值，否则往往会阻碍强度的增加。