The expansive clay soils, which cover most of the new urbanized areas in Egypt, create major damages in most of the engineering structures and infrastructures such as buildings, roads, bridges, pipelines and others due to bad human activities, e.g. lack of maintenance for sewage and drinking lines, and flood irrigation of golf areas which causes fluctuation of water content through the foundation clay layers associated with shrink-swell behavior. These geotechnical challenges and their treatment solutions consume most of the urbanized project budget and delay the development plan. Therefore, in this study the high plasticity and soft to firm clay soils were stabilized using various dosages of fresh cement kiln dust (CKD) as an economical alternative to the other expensive stabilizing agents (stabilizers or binders) such as lime, cement and other chemical stabilizers. The effectiveness of this type of CKD as a stabilizing agent, soil stabilization mechanism, and changes in mineralogical and microstructural characteristics of stabilized soils due to this stabilization process were evaluated through Atterberg limits, unconfined compressive strength (UCS), stiffness (stress–strain behavior, E_s), pH, electrical conductivity (EC), total dissolved solids (TDS), X-Ray diffraction (XRD) and scanning electron microscope (SEM) investigations. The present study revealed that by adding CKD, the workability of the treated clays was increased by decreasing the liquid limit and plasticity index as well as increasing the bearing capacity and decreasing the settlement by increasing UCS and E_s. This study also showed that by adding CKD, the initial pH, EC, and TDS of CKD-clay system increased, creating favorable conditions for dissolution of edges and surfaces of clay flakes. The active montmorillonite clay flakes adsorbed the soluble calcium cation and sulfate anion on their surfaces that are rich in soluble silica and alumina and then the cation exchange and flocculation–agglomeration processes began. With curing, the pozzolanic products grew on the surfaces and edges of clay flakes and extended into the voids of the agglomerated inter-clay particles resulting in the filling of these micro-voids. The present investigation also found that, the progressive decreasing in pH, EC, and TDS values of CKD-clay systems through different curing periods is a good indicator for pozzolanic activity.

由于人类的不良活动（例如缺乏污水维护），膨胀的粘土覆盖了埃及大多数新的城市化地区，对大多数工程结构和基础设施（如建筑物，道路，桥梁，管道等）造成了严重破坏以及饮水管线，以及高尔夫球场的洪水灌溉，这会导致水的含量通过与收缩-膨胀行为相关的基础粘土层而波动。这些岩土挑战及其解决方案消耗了大部分城市化项目预算，并拖延了开发计划。因此，在这项研究中，使用各种剂量的新鲜水泥窑粉尘（CKD）替代了其他昂贵的稳定剂（稳定剂或粘合剂），例如石灰，水泥和其他化学稳定剂。通过Atterberg极限，无侧限抗压强度（UCS），刚度（应力-应变行为）评估了这种CKD作为稳定剂的有效性，土壤稳定机理以及由于这种稳定过程而导致的稳定土壤的矿物学和微观结构特征的变化。 ，ë_小号），pH值，电导率（EC），总溶解固体（TDS），X射线衍射（XRD）和扫描电子显微镜（SEM）的调查。本研究表明，通过添加CKD，通过降低液体极限和可塑性指数，以及通过增加UCS和E _s来增加承载力和减少沉降，可提高处理过的粘土的可加工性_。。这项研究还表明，通过添加CKD，CKD-粘土系统的初始pH，EC和TDS会增加，从而为溶解粘土薄片的边缘和表面创造了有利的条件。活性蒙脱土薄片在其表面富含可溶性二氧化硅和氧化铝，吸收了可溶性钙阳离子和硫酸根阴离子，然后开始了阳离子交换和絮凝-凝聚过程。通过固化，火山灰产物在粘土薄片的表面和边缘上生长，并延伸到附聚的粘土间颗粒的空隙中，从而填充了这些微孔。本研究还发现，通过不同的固化时间，CKD-粘土体系的pH，EC和TDS值逐渐降低是火山灰活性的良好指标。