The strength, durability and swelling behavior of cement-solidified dredged sludge (CDS) has been attracted more and more attention in recent years. This study performed a series of laboratory tests including unconfined compressive strength (UCS), water absorption, swelling tests and pH to investigate the effectiveness of using fly ash (FA) and nano-SiO₂ (NS) blended with Portland cement (PC) for DS solidification. Microstructural properties were also analyzed by conducting scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests. The results showed that the addition of FA and NS can significantly improve the UCS of CDS. Using FA and NS together as PC admixture can effectively improve the water resistance. Compared with FA, NS was more effective to reduce the water absorption and swelling of CDS. Adding 0.9% NS to CDS notably reduced the 7-day water absorption and swelling value by up to 40% and 67.5%, respectively. Furthermore, the addition of NS is beneficial to control the pH level of CDS. The SEM and XRD results showed that CSH and CAH gels were the major cementitious products inside solidified DS. The addition of NS contributed to the formation of additional CSH gels in CDS.

近年来，水泥固化疏dr污泥（CDS）的强度，耐久性和溶胀行为已引起越来越多的关注。这项研究进行了一系列实验室测试，包括无边压缩强度（UCS），吸水率，溶胀测试和pH值，以研究使用飞灰（FA）和纳米SiO ₂的有效性（NS）与硅酸盐水泥（PC）混合以进行DS固化。还通过进行扫描电子显微镜（SEM）和X射线衍射（XRD）测试来分析微观结构性能。结果表明，添加FA和NS可以显着改善CDS的UCS。将FA和NS一起用作PC掺合料可以有效提高耐水性。与FA相比，NS在降低CDS的吸水率和溶胀方面更有效。向CDS中添加0.9％的NS显着降低了7天的吸水率和溶胀值，分别高达40％和67.5％。此外，添加NS有利于控制CDS的pH水平。SEM和XRD结果表明，CSH和CAH凝胶是固化DS内部的主要胶凝产物。NS的添加有助于在CDS中形成其他CSH凝胶。