Zhang Jinrui, Niu Wenjun, Liu Zhen, Yang Youzhi, Long Wujian, Zhang Yuanyuan, Dong Biqin
State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China.
Guangdong Province Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China.
Materials (Basel). 2022 Nov 29;15(23):8496. doi: 10.3390/ma15238496.
The microstructure and performance of magnesium potassium phosphate cement (MKPC), a kind of magnesium phosphate cement (MPC), are determined by the hydration products. In this paper, the hydration behavior of MKPC is investigated through various material characterization methods and thermodynamic modeling, including X-ray diffraction (XRD), thermogravimetric and differential scanning calorimeter (TG/DSC), scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and GEMS software. The results of XRD, TG/DSC and SEM all indicate that K-struvite (MgKPO·6HO) is the main hydration product of MKPC. When the curing age is 1 day and 28 days, the TG data indicate that the mass loss of MKPC in the range of 60-200 °C is 17.76% and 17.82%, respectively. The MIP results show that the porosity of MKPC is 29.63% and 29.61% at the curing age of 1 day and 28 days, respectively, which indicates that the structure of MKPC becomes denser with the increase in curing age. In addition, the cumulative pore volume of MKPC at the curing age of 28 days is 2.8% lower than that at 1 day, and the pore diameters are shifted toward the small pores. Furthermore, the thermodynamic modeling is well suited to make an analysis of the hydration behavior of MKPC.
磷酸镁钾水泥（MKPC）作为磷酸镁水泥（MPC）的一种，其微观结构和性能由水化产物决定。本文通过多种材料表征方法和热力学建模对MKPC的水化行为进行了研究，包括X射线衍射（XRD）、热重与差示扫描量热仪（TG/DSC）、扫描电子显微镜（SEM）、压汞法（MIP）以及GEMS软件。XRD、TG/DSC和SEM的结果均表明鸟粪石（MgKPO·6H₂O）是MKPC的主要水化产物。养护龄期为1天和28天时，TG数据表明MKPC在60 - 200℃范围内的质量损失分别为17.76%和17.82%。MIP结果显示，养护龄期为1天和28天时，MKPC的孔隙率分别为29.63%和29.61%，这表明MKPC的结构随着养护龄期的增加而变得更加致密。此外，MKPC在28天养护龄期时的累积孔体积比1天时低2.8%，且孔径向小孔径方向移动。此外，热力学建模非常适合对MKPC的水化行为进行分析。
