Geopolymer-Based Building Blocks Using Construction and Demolition Waste: Fid-Bau Portal

Geopolymer-Based Building Blocks Using Construction and Demolition Waste

Zubair, Md. / Mahmood, Md. Humayun / Islam, G. M. Sadiqul

Brick and cement industries are booming with rapid urbanization and infrastructure revolution. Both sectors have a substantial carbon footprint, a significant concern for global warming. Clay brick production requires kiln burning, which causes air pollution. Moreover, traditional brick industries consume a considerable amount of topsoil layer from agricultural land. On the other hand, due to rapid urbanization and the growing housing needs, construction and demolition wastes are increasing each day. This study, therefore, aims to find an alternative solution by producing non-fired geopolymer building blocks using construction and demolition wastes. Fly ash and Ground Granulated Blast Furnace Slag (GGBS) based geopolymer binder and construction, and demolition waste filler are used to produce non-fired building blocks. The physical and mechanical characteristics of geopolymer building blocks are evaluated using various mix proportions. The activator molarity was varied to find out the optimum for geopolymer concrete. The investigated result reveals that all the prepared geopolymer building blocks achieved at least 17.2 MPa compressive strength as per ASTM C62. The produced specimens also satisfied BDS 208: 2009 standard for bricks. The highest compressive strength (36.5 MPa) was achieved with 60% GGBS and a 12 M NaOH activator. In general, the compressive strength of bricks tends to increase as GGBS amount and NaOH activator concentrations increase. These blocks have shown excellent results regarding water absorption capacity and efflorescence. The promising results create a more significant opportunity to establish an industry based on a non-fired, eco-friendly geopolymer building block which will reduce the carbon footprint and the pressure on the fertile topsoil layer of agricultural lands. This study will give a viable indication of the construction and demolition waste disposal issues.