Preparation of activated electrolytic manganese residue-slag-cement ternary blended cementitious material: Hydration characteristics and carbon reduction potential

The study aimed to develop a ternary blended cementitious material using activated electrolytic manganese residue (AEMR), slag, and cement as the primary raw materials. The research focused on investigating the hydration characteristics, micromechanical properties, and carbon emissions of this material. The findings indicate that the ternary blended cementitious material demonstrates favorable fluidity, compressive strengths, and microstructure when the AEMR dosage is below 15%. The compressive strength of the ternary blended cementitious material at 28 d exceeded 44 MPa with an AEMR dosage of 15%. The hydration characteristics suggest that the alkali-sulfate synergistic excitation system formed by the ternary blended cementitious material effectively enhanced the activity of slag and AEMR, leading to the production of more hydration products such as ettringite, C-(A)-S-H gel, and hydrotalcite. The smaller particle size of AEMR compared with cement and slag results in the unhydrated AEMR particles effectively filling the pores in the mixed mortar. This improvement in the pore structure ultimately leads to the increase of compressive strength. Moreover, the ternary system demonstrates effectiveness in reducing carbon emissions. Overall, this study presents a viable method for preparing AEMR-slag-cement ternary blended cementitious material.