A Comparative Assessment of Mechanical Properties of Lime Pozzolana Concrete Activated by Sodium Silicate Gel

Abstract

Concrete is a fundamental material in construction, second only to water in its widespread use. However, cement production—a key component of concrete—significantly contributes to global carbon dioxide (CO₂) emissions, exacerbating environmental pollution, global warming, and climate change. The cement manufacturing process is highly energy-intensive and releases substantial CO₂ due to the chemical conversion of limestone into clinker. Researchers are exploring sustainable alternatives such as hydraulic lime, fly ash, and sodium silicate gel. These materials serve as effective chemical activators in the formation of lime pozzolana concrete, which offers a more eco-friendly solution by substantially reducing CO₂ emissions associated with cement production. In this study, a specific mix design ratio of lime pozzolana concrete, in accordance with the relevant Indian Standard (IS) code, was selected for structural-grade concrete. The specimens underwent curing using the normal water and wet hessian method to promote the hydration of cementitious materials and strength development. Mechanical properties, including compression, split tension, and flexure strengths, were evaluated at 7, 28, 56, 90 and 180 days. The test results of specimens that underwent normal water curing gave better strength results when compared with the wet hessian curing method and met the strength requirements specified in the IS code, demonstrating the feasibility of lime pozzolana concrete as a sustainable alternative to conventional cement-based concrete