Mechanical properties of geopolymer concrete incorporating supplementary cementitious materials as binding agents

Abstract

This research investigates the environmental impact of cement production by exploring eco-friendly geopolymer binders as alternatives. Geopolymer concrete, developed using silica and alumina-rich precursors such as pozzolanic materials, achieves high compressive strength, up to 43.6 N/mm2 with a 16 M concentration and integrated steel fibers. Utilizing manual mixing and industrial by-products, the study pioneers cast-in-situ geopolymers with innovative curing techniques. The paper presents experimental results on the engineering properties of geopolymer concretes of 40 MPa, cured at 100 °C and 60 °C. The study systematically varies binder content, examining proportions of fly ash, GGBS, metakaolin, and silica fume, along with different mix ratios and molar concentrations. Key findings include increased compressive strength with higher NaOH concentration, peaking at 35.2 N/mm2 and 34.22 N/mm2 for 14 M mixes at 7 and 28 days, and 40.29 N/mm2 for 16 M mixes at 7 days. Optimal results were observed at higher curing temperatures, especially with 14 M and 16 M compositions at 100 °C. The study recommends mechanized mixing for efficiency and calls for further investigation into the microstructure and chemistry of geopolymers to advance sustainable construction practices. This research represents a significant step towards eco-conscious building materials, reducing the environmental impact of the construction industry.