Title:
Axial Compression Constitutive Model of BA–MPC after High Temperatures (Prepublished)
Author(s):
Qi Cao, Jincai Zhu, Xiaokai Meng, and Boyu Guo
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
axial compression constitutive model; damage; high temperatures; magnesium phosphate cement; municipal solid waste incineration bottom ash
DOI:
10.14359/51749332
Date:
11/20/2025
Abstract:
This research aims to provide a theoretical foundation for the structural design of magnesium phosphate cement (MPC) in high-temperature environments and facilitate the recycling of municipal solid waste incineration bottom ash (BA). Uniaxial compression tests of BA–MPC after exposure to temperatures from 20°C to 1000°C were carried out. Subsequently, the stress-strain curve, peak stress, peak strain, and deformation modulus are examined. The peak stress, peak strain, and deformation modulus, considering the influence of temperature factors, are proposed using regression analysis. Based on the continuum damage mechanics, the axial compression damage constitutive model of MPC is developed, accompanied by an analysis of its temperature damage characteristics. The results show that BA improves MPC strength and helps stabilize its deformation after exposure to high temperatures. The peak stress of MPC decreases after exposure to high temperatures, and the peak stress of BA–MPC is higher at the same temperature. At 1000°C, the peak stress of MPC ranges between 15.86 MPa and 28.38 MPa. After high thermal exposure, the peak strain fluctuation of the MPC with BA stays small, and the deformation modulus is higher than that of the MPC without BA. The developed MPC axial compression damage constitutive model can accurately describe the stress-strain relationship of MPC under axial compression following high-temperature exposure, with a correlation coefficient greater than 0.86. The temperature damage variable of MPC rapidly accumulates in the range of 20°C to 200°C. At 600°C, the temperature damage variable and the total damage variable without BA attained the maximum values of 0.656 and 0.751, respectively. BA can reduce the total damage and temperature damage of MPC to a certain extent.