Sustainable innovation: Green interlocking geopolymer bricks for eco-friendly construction

Achieving sustainability by incorporating recycled materials in construction industry is considered as a viable solution to lower environmental burden. This study focuses on a similar solution by producing eco-friendly interlocking bricks in two directions made using geopolymer concrete having recycled fly ash. 24 geopolymer mixtures were investigated by varying ratios of Sodium metasilicate and Sodium Hydroxide, alkaline activator/fly ash, and molarity levels, to produce these innovative bricks. Afterward, double interlocking bricks were developed using optimized geopolymer mixture and tested for mechanical and durability related properties. Moreover, different structural wall panels were made using developed interlocking bricks and conventional burnt clay bricks and tested under out of plane loading. The results revealed that the mixture with the Sodium Hydroxide concentration of 14 molar, alkaline activator/fly ash of 0.5, and Sodium metasilicate to Sodium Hydroxide of 1.5 achieve the minimum compressive strength for brick manufacturing (15 MPa) of ambient-cured geopolymer. It was observed that green interlocking geopolymer bricks (GIGBs) showed better mechanical and durability characteristics than conventional burnt clay bricks. Moreover, GIGBs exhibited higher shear strength than that of conventional burnt clay bricks due to presence of keys and notches. Further, the minimum shear strength of 2.07 MPa was observed for single notch key of developed interlocking brick. The interlocking brick wall panel showed flexural capacity of 0.45 MPa as compared to that of 0.11 MPa for conventional burnt clay brick wall panel. Enhanced mechanical properties and reduced emissions of carbon dioxide bring us to a conclusion that GIGBs provide a sustainable and ecofriendly alternative to construction stakeholders to be used in construction industry for sustainable development of society.