The present study explores a cost-effective method for using activated ground granulated blast furnace slag (GGBFS) and silica fume (SF) as cement substitutes. Instead of activating them with expensive alkali solutions, the present study employs industrial-grade powdered soda ash (SA) and hydrated lime (HL) as activators, reducing expenses by about 94.5% compared to their corresponding analytical-grade counterparts. Herein, the exclusivity is depicted using less pure chemicals rather than relying on reagents with 99% purity. Two mixing techniques are compared: one involves directly introducing powdered SA and HL, while the other pre-mixes SA with water before adding it to a dry powder mixture of GGBFS, SF, and HL. Microstructural analysis reveals that the initial strength results from various hydrate phases, including calcium-sodium-aluminate-silicate hydrate (CNASH). The latter strength is attributed to the coexistence of calcium-silicate hydrate (CSH), calcium-aluminate-silicate hydrate (CASH) and sodium-aluminate-silicate hydrate (NASH), with contributions from calcite and hydrotalcite. The SF content significantly influenced the formation of these gel phases. Thermogravimetric analysis (TGA) reveals phase transitions and bound water related to hydration products. The optimal mix comprises 10% SF, 90% GGBFS, 9.26% HL, and 13.25% SA, with a water-to-solids ratio of 0.45. This approach yields a compressive strength of 35.1 MPa after 28 days and 41.33 MPa after 120 days, hence suitable for structural construction.

翻译：本研究探索了一种经济有效的方法，利用活化磨细粒化高炉矿渣（GGBFS）和硅灰（SF）作为水泥替代材料。与使用昂贵的碱溶液进行活化不同，本研究采用工业级粉状苏打灰（SA）和熟石灰（HL）作为活化剂，与相应的分析纯试剂相比，成本降低了约94.5%。此处的独特性体现在使用纯度较低的化学品，而非依赖纯度达99%的试剂。本研究比较了两种混合技术：一种是直接加入粉状SA和HL；另一种是先将SA与水预混，然后再将其加入由GGBFS、SF和HL组成的干粉混合物中。微观结构分析表明，早期强度源于多种水合物相，包括钙-钠-铝硅酸盐水合物（CNASH）。后期强度则归因于硅酸钙水合物（CSH）、铝硅酸钙水合物（CASH）和铝硅酸钠水合物（NASH）的共存，并伴有方解石和水滑石的贡献。SF含量显著影响了这些凝胶相的形成。热重分析（TGA）揭示了与水化产物相关的相变和结合水。最优配合比为：10% SF、90% GGBFS、9.26% HL和13.25% SA，水固比为0.45。该方法得到的材料在28天后的抗压强度为35.1 MPa，120天后达到41.33 MPa，因此适用于结构工程。