Influence of FeCl3⋅6H2O on the Hydration Hardening and Water Resistance of Magnesium Potassium Phosphate Cement

• Published in: ChemistrySelect (Weinheim) Vol. 5; no. 17; pp. 5156 - 5161
• Main Authors: Zhu, Yanjiao, Wang, Zhen, Li, Zhifeng, Yu, Haibin
• Format: Journal Article
• Language: English
• Published: 08.05.2020
• Subjects: Hydration temperature; Magnesium potassium phosphate cement; Mechanical properties; Phase transition; Water resistance
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202000306

Magnesium potassium phosphate cement (MKPC) is an ideal repair material due to its rapid curing advantages, but the setting time is too short to be applied in practical applications. In this work, FeCl3⋅6H2O was incorporated to MKPC to reduce the hydration temperature and prolong the setting time. Comprehensive investigation was performed on the influence of FeCl3⋅6H2O on the hydration temperature, setting time, mechanical properties, water resistance and microstructure of MKPC. The results showed that during the hydration process, FeCl3⋅6H2O underwent a phase transition and absorbed part of the hydration heat, which delayed the hydration heat release rate and effectively extended the setting time. In addition, the incorporation of FeCl3⋅6H2O with suitable contents had a positive impact on the compressive strength and water resistance. Finally, the optimal content of FeCl3⋅6H2O was determined to be 1.0%. The FeCl3⋅6H2O incorporated into magnesium potassium phosphate cement (MKPC) underwent a phase transition during the hydration reaction, absorbed and consumed part of the hydration heat, which relieved the continuous increase in system temperature, delayed the hydration heat release rate and improved workability of MKPC. Besides, Fe3+ reacted to form a gel‐like substance with a continuous structure, which can fill the pores, resulting in improved the late‐stage compressive strength and water stability of MKPC.