HYDRATING CHARACTERISTICS OF MODIFIED PORTLAND WITH Ba-BEARING SULPHOALUMINATE MINERALS

摘要

The hydrating characteristics of modified Portland cement with Ba-bearing sulphoaluminate minerals were studied in this paper. Scanning Electron Microscopy-Energy Dispersive Spectrometer (SEM-EDS), mercury intrusion porosimeter(MIP) and compressive strength were determined to characterize hydrating products and microstructure. Results show that basic physical properties of modified Portland cement with Ba-bearing sulphoaluminate minerals (SMPC) are similar with PC except the shorter setting time. Ettringite and C-S-H are the main hydrating produces in SMPC, which is similar to Portland cement (PC). Because of volume expansion of ettringite, SMPC paste structure is denser than PC according to SEM-EDS analysis and the pore size and pore content of SMPC pastes was smaller especially for the harmful pores. Because sulfur aluminum barium calcium was a new early-strength mineral and parts of BaO went into the C2S lattice and caused lattice distortion to enhance C2S hydration activity, the compressive strengths of SMPC grew faster and higher than PC.