Production and use of AAC in India

AAC was introduced in India in 1970s. However, there were only three factories producing a total of less than 1 million m³/year till 2008. Post 2009, AAC blocks gained popularity due to their numerous advantages, including high strength, excellent insulation properties, fire resistance, sound absorption, and cost advantages over alternate walling materials. The use of AAC blocks has also been promoted by the Indian government's emphasis on sustainable and eco‐friendly building materials. The number of factories increased rapidly to over 150 factories with a cumulative capacity of over 25 million m³/year in 2022 (a growth of 25 times in nearly 15 years). Despite the rapid growth, the share of AAC in walling industry in India is still in the range of 5%–6%. There is still a lot of room for the industry to grow. AAC reinforced products have also been recently re‐introduced in India, though it is still at a very nascent stage and the share of AAC reinforced products in total AAC sales is less than 1%. More than 95% of AAC industry in India uses fly ash as the primary raw material and faced challenges initially to stabilize the design mix, due to variations in raw material characteristics. The rapid growth also resulted in improper implementation of standards and processes, during both production and application. The primary issue on the production side has been lower compressive strength and higher corner chipping. The main challenge on the application side has been improper techniques such as non‐usage of reinforcement beams and fiber meshes, which led to cracks in masonry subsequently. Now, the AAC industry is working together with applicators and researchers to overcome these challenges, in order to consolidate the gains and continue the rapid growth trajectory to become the preferred walling material.