Geopolymer as a low-carbon binder can effectively reduce carbon emissions and improve industrial waste utilization. To optimize the performance of GGBS-FA binary geopolymer, a ternary geopolymer was designed by the addition of desulfurization gypsum (DG). The engineering properties of GGBS-FA-DG ternary geopolymers were investigated by laboratory tests. Moreover, microstructure tests were performed to reveal the improvement mechanism of the engineering properties of the ternary geopolymers. Results show that the compressive strength of ternary geopolymer with 60% GGBS was higher than that with 70% GGBS. With the increase in addition amount of DG, the strength first increased and then decreased, and the optimal DG content was 6%. However, the strength of ternary geopolymers with 50% GGBS was barely improved and remained the lowest. Initial and final setting times were prolonged with the increase in DG content, and the initial setting time reached 34 min for the optimal ternary geopolymers (i.e., 60% GGBS, 6% DG). Drying shrinkage was reduced by 15.8% as the DG content increased to 8%. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results revealed that gel products and needle-like ettringite (AFt) crystals were generated in the ternary geopolymers. AFt can fill the pores and further improve the strength based on the gel strength. AFt wrapped on the surface of early-formed aluminosilicate can prevent it from further polycondensation into three-dimensional network gels, thus retarding the setting at the early curing stage. In addition, the beneficial expansion of AFt can inhibit the drying shrinkage for the ternary geopolymers with the optimal DG content.

地质聚合物作为低碳粘结剂，可有效减少碳排放，提高工业废弃物利用率。为了优化 GGBS-FA 二元地质聚合物的性能，通过添加脱硫石膏 (DG) 设计了三元地质聚合物。通过实验室试验研究了 GGBS-FA-DG 三元地质聚合物的工程性能。此外，还进行了微观结构测试以揭示三元地质聚合物工程性能的改善机制。结果表明，GGBS 含量为 60% 的三元地质聚合物的抗压强度高于 GGBS 含量为 70% 的三元地质聚合物。随着DG添加量的增加，强度先升高后降低，最佳DG添加量为6%。然而，50% GGBS的三元地质聚合物的强度几乎没有提高，仍然是最低的。随着DG含量的增加，初凝和终凝时间延长，最佳三元地质聚合物（即60% GGBS，6% DG）的初凝时间达到34 min。当 DG 含量增加到 8% 时，干燥收缩率降低了 15.8%。扫描电子显微镜 (SEM) 和 X 射线衍射 (XRD) 结果表明，三元地质聚合物中生成了凝胶产物和针状钙矾石 (AFt) 晶体。AFt可以填充孔隙，在凝胶强度的基础上进一步提高强度。AFt包裹在早期形成的硅铝酸盐表面，可以阻止其进一步缩聚成三维网络凝胶，从而延缓早期固化阶段的凝固。此外，AFt的有益膨胀可以抑制具有最佳DG含量的三元地质聚合物的干燥收缩。