In the quest for sustainable construction materials, researchers have turned to an often-overlooked resource: fly ash, the by-product of coal combustion. A recent study published in ‘Cleaner Materials’ (translated to English as ‘Cleaner Building Materials’) offers a promising framework for optimizing fly ash cement bricks (FACB), integrating technical performance, environmental assessment, and economic viability. The lead author, Mohammed Rihan Maaze from the School of Engineering at NICMAR University in Pune, Maharashtra, India, and his team have developed a holistic approach that could reshape the construction industry’s approach to sustainable materials.
The study proposes a novel framework that optimizes FACB production through a parametric investigation using the Taguchi orthogonal array design. This method considers three critical factors: fly ash content (50–70%), cement content (7.5–12.5%), and water-to-binder ratio (20–24%). The research aims to achieve a target compressive strength of 10 MPa while minimizing water absorption, shrinkage, efflorescence, and Global Warming Potential (GWP).
Maaze explains, “Our goal was to create a comprehensive framework that not only enhances the technical performance of fly ash cement bricks but also considers the environmental and economic aspects. This multi-criteria approach ensures that the solution is sustainable and viable for large-scale industrial manufacturing.”
The study’s Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA) were conducted in accordance with ISO 14040/44 and ISO 15686 standards. The LCA results, with zero mass allocation of fly ash, indicated that the GWP per brick ranged from 0.58 to 0.77 kg CO2 eq, with cement content and transportation being the primary contributors to emissions. The LCCA assessment demonstrated a competitive production cost of ₹5.44 (0.06$) per brick, making it financially viable for large-scale industrial manufacturing.
The optimal mix proportions identified were 60% fly ash, 10% cement, and a 22% (0.22) water-to-binder ratio. These proportions were experimentally validated with a 95% confidence interval, confirming the accuracy of the predicted response properties. The improved compressive strength and reduced water absorption were attributed to enhanced matrix densification from cement hydration, while lower shrinkage and efflorescence resulted from the filler effect and pozzolanic activity of fly ash.
This research provides a comprehensive framework for industries and Micro, Small, and Medium Enterprises (MSMEs) to enhance production efficiency, reduce costs, and promote sustainable manufacturing practices. The findings could significantly impact the construction industry, particularly in regions with abundant fly ash resources, offering a sustainable alternative to traditional cement bricks.
As the construction industry continues to seek sustainable solutions, this study offers a promising approach to optimizing fly ash cement bricks. The holistic framework developed by Maaze and his team could pave the way for future developments in sustainable construction materials, shaping the industry’s approach to environmental and economic viability.