Addition of sulphoaluminate expansive agent could be one useful method to reduce the shrinkage crack destruction of shotcrete. While the setting and hardening behavior and early age mechanical strength of cement pastes containing liquid setting accelerators may be influenced by the introduction of sulphoaluminate expansive agent (SEA). Therefore, in this work, the early age hydration behavior of different accelerated cement pastes with SEA was investigated via setting times measurement, early age mechanical strength test, isothermal calorimeter, mineralogical composition, thermal gravimetric analysis (TGA) and scanning electron microscope with EDS detection. Results showed that the ability of liquid setting accelerators on shortening the setting times of cement pastes could be enhanced by the addition of SEA, especially for alkali-free type accelerator due to the prompted formation of massive rod-like ettringite phase. In addition, the further hydration extent of C3S phase in accelerated cement pastes was advanced by more dissipative portlandite phase to form such massive rod-like ettringite, thus improving the initial mechanical strength.

添加硫铝酸盐膨胀剂可能是减少喷射混凝土收缩裂缝破坏的一种有效方法。虽然硫铝酸盐膨胀剂 (SEA) 的引入可能会影响含有液体促凝剂的水泥浆的凝结和硬化行为以及早期机械强度。因此，在这项工作中，通过凝结时间测量、早期机械强度测试、等温量热仪、矿物组成、热重分析（TGA）和带有 EDS 检测的扫描电子显微镜，研究了不同 SEA 加速水泥浆体的早期水化行为。 . 结果表明，加入SEA可以增强液体促凝剂缩短水泥浆凝结时间的能力，特别是对于无碱型促进剂，由于促进了块状棒状钙矾石相的形成。此外，C3S 相在加速水泥浆体中的进一步水化程度通过更耗散的硅酸盐相促进，形成这种块状棒状钙矾石，从而提高了初始机械强度。