Compressive Strength of Steel Slag-based Geopolymer Concrete and Investigation of Influencing Factors

In recent years, geopolymer has been introduced as a novel and green alternative to the Portland cement. Compressive strength is considered as one of the important characteristics of concrete. In geopolymer concretes, according to the ingredients, several factors have been identified as important parameters affecting the compressive strength. Hence, in this experimental research, several factors affecting the compressive strength steel slag-based geopolymer concrete including: the type of alkaline activator solution, the weight ratio of water to solid material participated in geopolymerization, sodium hydroxide concentration, the weight ratio of alkaline activator solution to aluminosilicate source and sodium silicate to sodium hydroxide weight, were studied. The obtained results indicated that using potassium hydroxide and potassium silicate as an alkaline activator solution, result in higher 28-day compressive strength of compare to sodium-based alkaline activator solution. On the other hand, using sodium hydroxide and sodium silicate as an alkaline activator solution, result in higher 3- and 7-day compressive strengths and also, faster hardening. Furthermore, increasing the weight ratio of water to solid material result in significant decreasing geopolymer concrete compressive strength. Also, compressive strength is increases with increase in concentration of sodium hydroxide up to 14 M, but for 16 M, there is no remarkable changes in compressive strength. The optimum ratio of alkaline activator solution to steel slag and sodium silicate to sodium hydroxide was measured 0.5 and 1.5, respectively.

Compressive Strength of Steel Slag-based Geopolymer Concrete and Investigation of Influencing Factors Keywords:

Geopolymer concrete , steel slag , Compressive strength , Alkaline activator solution , Factors Influencing Compressive Strength