Fractal characteristics of pore structure of hardened cement paste prepared by pressurized compact molding

Abstract

The microstructure of hardened cement paste is directly related to its macroscopic properties. Pressurized compact molding can effectively improve the microstructure of hardened cement paste. In order to study the characteristics of pore structure of hardened cement paste and the mechanism of microstructure regulation and defect reduction after pressure compaction, Mercury Intrusion Porosimetry (MIP) and X-Ray Diffraction (XRD) was used to characterize the microstructure of hardened cement paste and the mass fraction of the main phase. Results indicate that the pressurized compact molding significantly reduced the total porosity and critical pore diameter of hardened cement paste, and the pore size was micro-nano. The pore surface fractal dimension (SFD) of the paste was multi-segmental fractal and scale dependent after compaction, and the irregular drift behavior in the transition region was not obvious. A new understanding of the pore volume distribution characteristics of hardened cement paste was proposed based on the change of main phase mass fraction.