Fluidized stabilized soil (FSS), characterized by high fluidity, self-compaction capability, and controllable strength, provides an innovative solution for backfilling narrow and geometrically complex voids in civil engineering. In this study, loess was utilized as the base soil, and FSS was synthesized by synergistically combining blast furnace slag (BFS), fly ash (FA), carbide slag (CS), and NaOH as composite binders. An orthogonal experimental design was implemented to evaluate the effects of varying mix proportions on fluidity, compressive strength, and cost efficiency. The optimal binder formulation was determined using fuzzy optimization theory. Under the optimal formulation, the influences of binder content, water-to-solid ratio (WSR), and curing age on fluidity, compressive strength, and water stability were systematically investigated. The hydration products and microstructural evolution were analyzed through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) to elucidate the stabilization mechanisms. Results revealed that the optimal binder composition comprised a 7:3 mass ratio of BFS to FA, 12 % CS content, and 0.5 % NaOH content. Fluidity increased with higher WSR or lower binder content, whereas compressive strength exhibited an inverse correlation, improving with lower WSR or higher binder content. The fluidity of specimens ranged from 157 to 320 mm, and the 28d compressive strength varied between 0.33 and 2.39 MPa. At 28d curing age, the water stability coefficient increased from 78.0 % to 91.4 % as binder content was elevated from 8 % to 20 %. The synergistic hydration of industrial solid wastes generated calcium silicate hydrate (C-S-H) and calcium aluminosilicate hydrate gels (C-A-S-H), which encapsulated soil particles and filled interparticle voids, thereby significantly enhancing soil strength. The stabilization mechanisms of FSS involved hydration of quicklime, ion exchange, alkali-activated pozzolanic reactions, and carbonation processes.

中文翻译：

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多源固废流态化固化土配比及强度形成机理优化

流态化稳定土 （FSS） 具有高流动性、自密实能力和可控强度的特点，为土木工程中狭窄和几何复杂的空隙回填提供了一种创新的解决方案。本研究以黄土为基土，以高炉渣 （BFS）、粉煤灰 （FA）、电石渣 （CS） 和 NaOH 为复合粘结剂协同结合合成了 FSS。实施了正交实验设计，以评估不同混合比例对流动性、抗压强度和成本效率的影响。使用模糊优化理论确定最佳粘合剂配方。在最佳配方下，系统研究了粘合剂含量、水固比 （WSR） 和固化年龄对流动性、抗压强度和水稳定性的影响。通过 X 射线衍射 （XRD） 、傅里叶变换红外光谱 （FT-IR） 和扫描电子显微镜 （SEM） 分析水合产物和微观结构演变，以阐明稳定机制。结果表明，最佳粘合剂组成包括 BFS 与 FA 的质量比为 7：3，CS 含量为 12%，NaOH 含量为 0.5%。流动性随着 WSR 的提高或粘合剂含量的降低而增加，而抗压强度则表现出负相关，随着 WSR 的降低或粘合剂含量的提高而提高。试件的流动性范围为 157 至 320 mm，28d 抗压强度在 0.33 至 2.39 MPa 之间变化。在 28 d 养护年龄时，随着粘合剂含量从 8 % 提高到 20%，水稳定性系数从 78.0 % 增加到 91.4 %。 工业固体废物的协同水化生成了水合硅酸钙 （C-S-H） 和铝硅酸钙水合物凝胶 （C-A-S-H），它们封装了土壤颗粒并填充了颗粒间空隙，从而显着提高了土壤强度。FSS 的稳定机制涉及生石灰的水化、离子交换、碱活化火山灰反应和碳酸化过程。