Enhanced characteristics of alkali activated slag/ grog geopolymer bricks [ ]


The development of alternatives to conventional Portland cement produced with more eco-efficient processes (lower energy consumption and carbon foot print) is of great importance to the industry and world climate. Alkaline cements and concretes are an effective alternative to these traditional cements. Geopolymer bricks that are prepared by partial binder substitution, water cooled slag, with clay brick waste (grog) in a ratio ranging from 0 up to 100%, and with a fine sand ratio of 15% of the total weight. Also, sodium hydroxide activator was used in a ratio of 8% of the total weight. The properties of the produced Geopolymer bricks have been investigated through measurement of compressive strength, water absorption, FTIR, XRD and SEM imaging. The results revealed the feasibility of substituting water cooled amorphous slag with grog in synthesization of Geopolymer bricks. Resulting in superior quality, where the compressive strength values, with a substitution of slag with up to 40% grog, exceeds 40 MPa and so can be used in production of heavy duty bricks that can withstand harsh weathering conditions. However, further substitution leads to the lowering of mechanical properties of the brick, as a result of increased crystalline content and deficiency of activator to dissolve all crystalline fractures.