Qiao Wei, Yue Bing, Luo Zhihua, Zhu Shengli, Li Lei, Yang Heng, Luo Biao
School of Engineering and Technology, China University of Geosciences (Beijing), Beijing 100083, China.
Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
Materials (Basel). 2025 Jul 14;18(14):3307. doi: 10.3390/ma18143307.
The utilization of steel slag (SS), fly ash (FA), and ground granulated blast furnace slag (GGBFS) as soil additives in construction represents a critical approach to achieving resource recycling of these industrial by-products. This study aims to activate the SS-FA-GGBFS composite with a NaOH solution and NaCO and employ the activated solid waste blend as an admixture for lateritic clay modification. By varying the concentration of the NaOH solution and the dosage of NaCO relative to the SS-FA-GGBFS composite, the effects of these parameters on the activation efficiency of the composite as a lateritic clay additive were investigated. Results indicate that the NaOH solution activates the SS-FA-GGBFS composite more effectively than NaCO. The NaOH solution significantly promotes the depolymerization of aluminosilicates in the solid waste materials and the generation of Calcium-Silicate-Hydrate and Calcium-Aluminate-Hydrate gels. In contrast, NaCO relies on its carbonate ions to react with calcium ions in the materials, forming calcium carbonate precipitates. As a rigid cementing phase, calcium carbonate exhibits a weaker cementing effect on soil compared to Calcium-Silicate-Hydrate and Calcium-Aluminate-Hydrate gels. However, excessive NaOH leads to inefficient dissolution of the solid waste and induces a transformation of hydration products in the modified lateritic clay from Calcium-Silicate-Hydrate and Calcium-Aluminate-Hydrate to Sodium-Silicate-Hydrate and Sodium-Aluminate-Hydrate, which negatively impacts the strength and microstructural compactness of the alkali-activated solid waste composite-modified lateritic clay.
将钢渣（SS）、粉煤灰（FA）和粒化高炉矿渣（GGBFS）用作建筑中的土壤添加剂，是实现这些工业副产品资源回收的关键途径。本研究旨在用氢氧化钠溶液和碳酸钠活化SS-FA-GGBFS复合材料，并将活化后的固体废弃物混合物用作红土改良剂。通过改变氢氧化钠溶液的浓度以及相对于SS-FA-GGBFS复合材料的碳酸钠用量，研究了这些参数对该复合材料作为红土添加剂的活化效率的影响。结果表明，氢氧化钠溶液比碳酸钠更有效地活化了SS-FA-GGBFS复合材料。氢氧化钠溶液显著促进了固体废弃物中铝硅酸盐的解聚以及硅酸钙水合物和铝酸钙水合物凝胶的生成。相比之下，碳酸钠依靠其碳酸根离子与材料中的钙离子反应，形成碳酸钙沉淀。作为一种刚性胶结相，碳酸钙对土壤的胶结作用比硅酸钙水合物和铝酸钙水合物凝胶弱。然而，过量的氢氧化钠会导致固体废弃物溶解效率低下，并使改性红土中由硅酸钙水合物和铝酸钙水合物生成的水化产物转变为硅酸钠水合物和铝酸钠水合物，这对碱激活固体废弃物复合材料改性红土的强度和微观结构致密性产生负面影响。
