Investigation of mechanical properties of geopolymer concretes with obsidian powder, blast furnace slag and metakaolin

İCEARC23, Trabzon, Türkiye, 12 - 14 Ekim 2023, ss.744-754

Purpose: Compressive, splitting tensile strengths and SEM analysis results of geopolymer concretes containing

obsidian powder, blast furnace slag and metakaolin are presented.

Study design/methodology/approach: The 100x100x100 mm cube-shaped geopolymer concrete specimens containing

kept in bags under normal ambient conditions. On the 28th day, compressive and splitting tensile strength tests were

carried out. SEM analysis was also performed to support the results of the mechanical tests.

Findings: Compressive strength of 61.73 MPa and tensile strength at splitting of 5.98 MPa were obtained in the the

OB0GGBS100MT0 specimens. In SEM images, a more compact and void-free structure was observed in the sample

with high strength.

Originality/value: Today, the increasing global warming phenomenon motivates researchers to search for green and

environmentally friendly materials. In this context, alkali-activated materials, in other words, geopolymers, are a general

solution to this search. Geopolymers can provide high mechanical strengths as well as reduce CO2 emissions, and can

also be a solution to storage problems by producing waste and natural materials. Although there are many different

powder precursors used for geopolymer concretes in the literature, the use of obsidian powder is very limited. The

mechanical properties of concretes containing obsidian powder were determined with the experiments carried out.