Activation of Portland cement blended with high volume of fly ash using Na2SO4

Autogenous shrinkage of slag-fly ash blends activated with hybrid sodium silicate and sodium sulfate at different curing temperatures

“…Early age compressive strength (1 day) of samples cured at 20°C is around 5-12 MPa. These strength values are considerably lower than sole sodium silicateactivated samples (25-30 MPa) [41,42] and Portland cement (around 20 MPa) [43]. However, the compressive strength remarkably improves after 3 days, and is comparable to that of sodium silicate activated samples reported in previous studies of the authors [31,11].…”

“…4). This manifests that the early age mechanical strength properties of the studied AASF can be determined from isothermal calorimetry heat release, similar to OPC-based materials described in [43,46].…”

Effect of Alkaline Salts on Calcium Sulfoaluminate Cement Hydration

“…The latter are characterized by high proportions of additions or cement replacements (usually fly ash (FA), blast furnace slag, or calcined clay) and a low PC content (<30%). Whilst either liquid or solid alkalis may be added to catalyze the initial reaction in the replacements [ 18 ], the use of solids, such as Na 2 CO 3 , Na 2 SO 4 , or Na 2 SiO 3 , are able to react with the portlandite forming during PC hydration, generating caustic soda in situ, is much more practical [ 19 , 20 , 21 , 22 ].…”

Hydration of polyphase Ca3SiO5‐Ca3Al2O6 in the presence of gypsum and Na2SO4

“…Previous studies have demonstrated a significant increase in the overall reactivity and mechanical properties, when high volume fly ash blends are activated with Na 2 SO 4 . [1][2][3][4][5] However, the current understanding of the effect of Na 2 SO 4 on the hydration of Portland cement systems is rather limited, and new knowledge is required to understand the fundamental mechanisms, potentials, and limitations of such systems.…”

“…Sodium sulfate (Na 2 SO 4 , ) acts as a potential activator to increase the reactivity and mechanical properties of blended systems with high Portland cement replacement levels. Previous studies have demonstrated a significant increase in the overall reactivity and mechanical properties, when high volume fly ash blends are activated with Na 2 SO 4 1‐5 . However, the current understanding of the effect of Na 2 SO 4 on the hydration of Portland cement systems is rather limited, and new knowledge is required to understand the fundamental mechanisms, potentials, and limitations of such systems.…”