The construction industry is continuously seeking sustainable alternatives to conventional building materials. Alkali-Activated Cellular Lightweight Binder Blocks (AACLBs) present a promising solution by utilizing alkali activation technology to augment the properties of lightweight concrete. This research focuses on optimizing the composition of AACLBs by replacing conventional binders with alkali-activated materials derived from industrial by-products and agro waste with the help of a protein based foaming agent (FA). The industrial waste materials investigated include Fly Ash (F) and Blast Furnace Slag (BFS) while agro waste such as Rice Husk Ash (RHA) are considered as sustainable alternatives. With Sodium Hydroxide (NaOH) and Sodium Silicate (Na₂SiO₃) as activators, 8 different combinations are adopted in this study. Properties such as density and compressive strength (CS) are analyzed to assess the structural capabilities of the AACLBs and are compared with that of cement-based blends. The alkaline solution to binder ratio is kept constant as 2.5 for two dilution ratios (1:30 & 1:60) and ambient curing is adopted. The target densities for conventional cement-based mixes are set as 1200–1600 kg/m³ and 1500–1800 kg/m³ for alkali-based mixes. The findings show that, the highest CS of 42.76 MPa and a density of 1870 kg/m³ is observed for FB1 combination at a dilution ratio of 1:30. Conversely, the FBR2 combination at a dilution ratio of 1:60 yielded a CS of 21.23 MPa, accompanied by a minimum density of 988 kg/m³.

The demand for concrete is increasing day by day due to vast development in urbanisation. One of the important ingredients to manufacture concrete is cement whose production is leading to large amount of carbon dioxide (CO2) releases attributing to global warming. To reduce the usage of cement in concrete, Supplementary Cementitious Materials (SCM) are given importance and plenty of research is done on them. SCM’s can replace cement upto permissible limits and enhance the concrete properties. The concretes that can replace the cement content completely are Geo Polymer Concrete (GPC) and Alkali Activated Concrete (AAC). They are eco-friendly concretes in which the wastes coming from various types of industries, treatment plants and agro wastes can be used as binders. Alkaline activator solution is used to activate the binder materials which is a combination of silicates and hydroxides. GPC and AAC has wide range of applications like making of concrete benches in park, balusters, paver blocks and non-load bearing components etc. In this paper, a novel mix design for AAC for a constant alkaline solution to binder ratio of 0.4 is presented. The molarity of sodium hydroxide used in this study is 10M. Various mix combinations of binders using Fly ash, Ground Granulated Blast Furnace Slag (GGBS) and Rice husk ash (RHA) were considered. Workability, Physical and mechanical properties of AAC mixes were determined including Non-Destructive tests (NDT). Mixes with RHA resulted in poor compressive strength as the water demand was high and curing under ambient conditions proved to be of low impact especially for AAC with RHA.