Optimisation of agro waste-based fibrous geopolymer concrete using experimental and statistical approach

The integration of agricultural waste ashes with fibre reinforcement presents a sustainable pathway for developing next-generation construction materials. This study investigates the influence of basalt fibre incorporation on the workability and mechanical performance of geopolymer concrete synthesized from rice husk ash, sugarcane bagasse ash, and cow dung ash. Experimental results revealed a parabolic trend across compressive, flexural, and split tensile strengths, with 1% basalt fibre identified as the optimum dosage for balanced performance. An optimum compressive strength of approximately 31 MPa at 90 days was achieved at 1% basalt fibre content. To complement the experimental findings, regression-based modelling and Response Surface Methodology (RSM) were employed to simulate and optimize the single-response behaviour of the mixes. The RSM models predicted the optimum fibre dosage, confirming 1% fibre as the most effective balance point between strength enhancement and slump retention. This combined experimental–statistical approach underscores the significance of optimization tools in advancing eco-efficient concrete technology. The findings highlight the potential of basalt fibre–ash-based geopolymer systems, optimized through RSM, to achieve durable, structurally reliable, and environmentally sustainable alternatives to conventional cementitious composites. Unlike conventional geopolymer studies focusing on single precursor systems or heat curing, this study introduces a hybrid agro-waste binder under ambient curing conditions combined with regression-based optimization, providing a practical and sustainable solution for real-world construction. Introduces a hybrid agro-waste binder system (RHA, SBA, CDA). Demonstrates parabolic strength behaviour. Establishes 1% fibre content as the optimum dosage. Validates results using regression-based optimisation. Highlights sustainability potential.