To improve the durability of offshore concrete and the incorporation of steel slag powder within the concrete matrix, a series of tests were conducted to evaluate the fluidity, setting time, mechanical properties, carbonation depth, and chloride ion electric flux of steel slag concrete. The study investigated the influence of three different activators—sodium sulfate, desulfurization gypsum, and desulfurization ash—on the activity of steel slag, as well as the concrete's resistance to chloride ions and carbonation. The findings indicate that the inclusion of steel slag reduces the fluidity of cement paste and extends the setting time. Notably, sodium sulfate (Na2SO4) as an activator has the potential to marginally decrease the setting time. Both mineral powder and steel slag powder can mitigate the loss of concrete slump over time to a certain degree; however, the presence of a specific quantity of activator may diminish this effect. The use of desulfurization ash (at a concentration of 2%), sodium sulfate (at 3%), and desulfurization gypsum (at 4%) significantly enhanced the flexural strength of the concrete, with the 3% Na2SO4 (designated as SS-N) demonstrating the most substantial contribution to flexural strength. The combination of sodium sulfate and desulfurization gypsum (referred to as SS-NG) exhibited a greater impact on the flexural strength of the concrete compared to the combination of sodium sulfate and desulfurization ash (SS-ND) or the use of individual activators. When the three activators were applied independently, a slight improvement in the 7-day compressive strength of concrete containing steel slag-slag powder was observed, although the enhancement in later compressive strength was not pronounced. Conversely, the composite activator demonstrated a significant influence on the compressive strength of the concrete, particularly the combination of 3% sodium sulfate and 4% desulfurization gypsum, which markedly affected the mechanical properties. Furthermore, sodium sulfate improved the carbonation resistance and chloride ion penetration resistance of the concrete by 23.9% and 43.7%, respectively. The durability benefits of the composite activator comprising sodium sulfate and desulfurization gypsum surpassed those of any single activator. Overall, the three activators—desulfurization ash, desulfurization gypsum, and sodium sulfate—enhanced the activity of steel slag, thereby improving the microstructure, mechanical properties, and durability of offshore concrete.
Experimental on effect of steel slag activator on mechanical properties and durability of offshore concrete
2024
Article (Journal)
Electronic Resource
Unknown
Metadata by DOAJ is licensed under CC BY-SA 1.0