3. Life Cycle Assessment to Identify Sustainable Lime-Pozzolana Binders for Repair of Heritage Structures

Lime has been used as a binding material in construction of monuments, forts, temples, etc., since time immemorial and throughout the world. With the advent of cement in nineteenth century, usage of lime started deteriorating. However, use of lime is inevitable in heritage structures as it is the compatible material for repair of such ancient structures. Though commercial production of hydraulic lime got reduced in developing countries, abundant availability of non-hydraulic limes with addition of pozzolanas, namely GGBS and fly ash can contribute to the mechanical strength gain and other durability characteristics. This study focuses on the development of hydrated lime with pozzolanic replacements of fly ash or GGBS with different dosages with an aim to develop sustainable mortars for repair of heritage structures. In this study, comparative analysis was done in terms of energy, carbon dioxide emissions, and other environmental effects of lime-pozzolana-based mortars with conventional cement mortars based on LCA in the background. Based on the various parameters investigated, it is concluded that lime–fly ash-based mortars with 75% pozzolanic replacement was found to be a sustainable alternative.