The Study of Mechanical Properties of Geopolymer Bricks prepared by using Iron Ore Tailings

Abstract

Bricks are a widely used construction and building material. Brickmaking is a predominantly rural industry with brick-making units
belonging to the small and informal sectors. Conventional production of bricks usually utilizes clay and shale as the source material and
often requires higher temperatures (900 – 1000 ℃) in kiln firing. Good agricultural soil is preferred as the raw material for making
bricks in India. The brick industry is estimated to consume around 400 million tons of good-quality soil every year. The burning of fuel
for firing bricks results in emissions of gaseous pollutants and ash into the environment. Brick-firing being an energy-intensive process,
the brick industry is one of the largest consumers of coal (around 24 million tons/year) in the country and hence is also an important air
polluter. The current study presents a methodology for making geopolymer bricks in environmentally friendly manner by using iron
ore mine tailings, sodium silicate and a suitable binder. The study is based on the geo-polymerisation process, which is known to
conserve energy by reducing the emissions of greenhouse gases. In this study, the sodium silicate is added to the iron ore mine tailings
with a suitable binder for the formulation of the geopolymer bricks and curing for 7, 14 and 28 days. The mechanical properties of
geopolymer bricks are investigated; per se compressive strength, brick density, water absorption, dimensionality test, falling test,
efflorescence test, soundness test, hardness test, structure test, and XRD. The results will allow us to see the efficacy of
geopolymerisation as an effective technique.
Keywords: Geopolymer bricks, Iron ore mine tailings, Sodium silicate, Binder, Geo-polymerisation process, Durability test