| Abstrakt: |
This study investigates the influence of various types and dosages of sulfatic and alkaline activators on the performance of low emission supersulfated blast furnace slag cements. The effects on compressive strength, drying shrinkage, hydration products composition, and microstructure were analyzed. A Taguchi L25(5)4 orthogonal array was employed to efficiently explore the design space. The optimal composition at 28 days (82.5% slag, 13.12% fluorgypsum and 4.38% Portland cement) had predicted/experimental strengths of 39.9/35.3 MPa, while at 90 days (90% slag, 7.5% fluorgypsum and 2.5% Portland cement) the predicted/experimental strengths of 51.4/49.9 MPa. Microstructural characterization through XRD, ATG/DTA and SEM showed that a sulfatic to alkaline activator ratio of 3:1 promoted slag reactivity, leading to dense microstructures rich in calcium silicate hydrates, ettringite and gypsum. The studied binders exhibited significantly lower CO2 emissions of at least 79% and cost up to 71% compared to Portland cement. [ABSTRACT FROM AUTHOR] |
