Investigation of mechanical properties and chemical durabilty of the ground granulated blast furnace slag based geopolymer concretes under 5% sulfuric acid environment

In this study, the strength and durability performance of 100% ground granulated blast furnace slag based geopolymer concretes under 5% sulfuric acid was investigated. Our aim is to examine the strength and durability performances of geopolymer concretes having different binder contents and alkali activator/binder ratio cured in the laboratory environment. Three different binder amounts were selected as 400 kg/m3, 500 kg/m3, 600 kg/m3 as binder content. The alkali activator/binder ratios were chosen as to be 0.45 and 0.55, taking into account the durability requirements. In the scope of the research, strength and 5% sulfuric acid resistances of 6 different geopolymer concrete types were investigated. As an alkali activator, sodium silicate and sodium hydroxide were utilized in the geopolymer concrete production. The sodium silicate and sodium hydroxide ratio was selected as 2.5, and sodium hydroxide molarity was chosen as 14 M. Additional water was also used to increase workability and geopolymerization. The produced 6 different concretes were kept in both laboratory and 5% sulfuric acid solutions until the 28th, 120th and 150th days, and the surface, weight and compressive strength changes in the samples due to sulfuric acid were investigated in details.