Calcium aluminate cement (CAC) shows some superior properties compared to Portland cement. However, the conversion of metastable hydrates limits the application of traditional CAC. This study reports a low cost and high strength quaternary phase (Q phase, Ca₂₀Al₂₆Mg₃Si₃O₆₈)-metakaolin (MK) composite. The mechanical property and microstructure of this composite hydrated at ambient temperature were investigated. The results indicate that incorporating 15% MK into Q phase paste leads to a highly dense and homogeneous microstructure and the resulting composite achieves a continuous strength development within 120 days and gains a high ultimate compressive strength up to 110 MPa, without experiencing a strength loss, attributed to the continuous formation of nanoscale CAH₁₀ and AH₃. In contrast, the control paste made without MK shows an obvious decrease in strength due to the formation of a large number of pores in outer products caused by the conversion of initially formed hydrates. The results of XRD, BSE/EDS and ²⁹Si and ²⁷Al NMR indicate that the beneficial effect of MK on the mechanical property and microstructure of Q phase paste mainly arises from its pentahedral Al.

与波特兰水泥相比，铝酸钙水泥（CAC）具有一些优越的性能。然而，亚稳水合物的转化限制了传统CAC的应用。这项研究报告了低成本和高强度的四元相（Q相，Ca ₂₀ Al ₂₆ Mg ₃ Si ₃ O ₆₈）-偏高岭土（MK）复合材料。研究了在室温下水合该复合材料的力学性能和微观结构。结果表明，将15％MK掺入Q相糊料会导致高度致密且均匀的微观结构，所得复合材料可在120天内实现连续强度发展，并获得高达110 MPa的高极限抗压强度，而不会出现强度损失，归因于纳米级CAH ₁₀和AH ₃的连续形成。相反，由于最初形成的水合物的转化导致在外部产品中形成大量的孔，因此不含MK的对照糊剂的强度明显降低。XRD，BSE / EDS和²⁹ Si和²⁷ Al NMR表明，MK对Q相糊的机械性能和微观结构的有益影响主要来自其五面体Al。