Investigation and Optimisation of the Rheological Properties of Magnesium Potassium Phosphate Cement with Response Surface Methodology

• Published in: Materials Vol. 15; no. 19; p. 6815
• Main Authors: Yue, Yanfei, Ren, Jun, Yang, Kai, Wang, Danqian, Qian, Jueshi, Bai, Yun
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30-09-2022; MDPI
• Subjects: Analysis; Borax; Cement; Design techniques; Dosage; Hydrates; Hydration; Independent variables; Investigations; Magnesium; Magnesium phosphate; magnesium potassium phosphate cement; Methods; mini slump; Optimization; Phosphates; plastic viscosity; Potassium phosphates; Research methodology; Response surface methodology; Rheological properties; Rheology; Variance analysis; Viscosity; Yield strength; Yield stress; United Kingdom; United Kingdom > UK; United States > US
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma15196815

Magnesium phosphate cement (MPC) is a promising alternative cement. However, the rheological property of this new binder is still to be explored. In this study, Response Surface Methodology (RSM) was adopted with Central Composite Design (CCD) to establish mathematical models describing the rheological characteristics of MPC in terms of initial mini slump (Y1), mini-slump loss (Y2), yield stress (Y3) and plastic viscosity (Y4), as a function of three independent variables, namely, water-to-solid ratio (W/S ratio, X1), MgO to MKP ratio (M/P ratio, X2) and borax dosage (X3). The results show that the M/P ratio and borax dosage could significantly affect the yield stress and mini-slump loss of MPC, while the W/S ratio was the significant coefficient influencing plastic viscosity and initial mini slump. The numerical optimised values of X1, X2 and X3 were 0.280, 7.528 and 0.170, respectively, and an MPC paste with desirable rheological characteristics (Y1 161.858 mm, Y2 11.282, Y3 0.680 Pa, Y4 0.263 Pa·s) with the highest desirability of 0.867 can be obtained.