# Sustainability Enhancement and Evaluation of a Concrete Dam Using Recycling
## 1 Introduction
Dams play a significant role in GHG emissions due to the extensive use of concrete in their construction, which involves the production of cement, a process known to emit substantial amounts of CO\({}_{2}\) during manufacturing [16]. The environmental implications spanning a dam's complete life cycle could be categorized into construction, maintenance, operation, and decommissioning stages. In pursuit of optimal sustainability in dam construction, LCA offers a valuable framework for exploring the trade-offs inherent in different alternatives [17]. LCA stands as a standardized technique to assess the ecological ramifications of a system or product over its complete life cycle [18]. This comprehensive analysis encompasses factors such as emissions, energy usage, and waste production. LCA has the capacity to gauge both the overall influence of a construction project throughout its existence and the specific effects associated with individual materials employed in its construction. Within the spectrum of environmental aspects subject to LCA scrutiny, the practice of carbon footprint analysis (CFA) emerges, a methodology designed to quantify the cumulative direct and indirect emissions of greenhouse gases (GHGs) stemming from an individual, entity, or product within a defined timeframe. While CO\({}_{2}\) represents the most prevalent GHG under consideration, the analysis also encompasses gases like methane (CH\({}_{4}\)) and nitrous oxide (N\({}_{2}\)O). Conversely, life cycle costing (LCC) serves as a method employed to appraise the comprehensive economic expenditure linked to a service or product over its life cycle [19]. In the realm of construction, LCA and CFA have been employed to assess the ecological effects stemming from different materials, construction techniques, and the sustainability of projects, as well as pinpoint avenues for enhancing environmental performance [20]. Implementing these approaches on a significant and influential construction holds paramount importance, as it facilitates a balanced assessment of the trade-offs between the advantages and drawbacks linked to its environmental impacts and resource utilization [21]. Researchers have delved into different dimensions of dam analysis within LCA, encompassing aspects like the utilization of dredged sediments [22], the decommissioning of dams [23], the decay of biomass within reservoirs, and the functioning of hydroelectric plants [23; 24; 25]. [PERSON] et al. [26] proposed an LCA method for carbon assessment in pumped storage hydropower projects, addressing a gap in estimating emissions at the design stage. By calculating diesel, electricity, and material use, the method helps identify emission influences of design factors, supporting greener pumped storage hydropower evaluations and improved emission estimates. In tandem with distinct building materials, [PERSON] et al. [27] utilized an LCA approach to assess the environmental repercussions of two types of dams, including conventional concrete and rock-filled concrete. The findings indicate that rock-filled concrete led to a reduction of 25% in transportation, 51% in construction, 72% in CO\({}_{2}\) emissions during material production, and 15.6% in maintenance and operation. Similarly, [PERSON] et al. [28] utilized a hybrid LCA method to juxtapose the carbon footprints of two varieties of hydropower schemes: a concrete gravity dam and an earth-core rockfill dam. The outcomes reveal that earth-core rockfill dams exhibit superior environmental responsibility throughout their life cycle, contributing to a roughly 24.7% decrease in CO\({}_{2}\) emissions in comparison to concrete gravity dams. Nonetheless, the current investigations focus solely on existing factors, neglecting the potential influence of future considerations such as recycling, which could significantly impact the maintenance and operation of structures. [PERSON] et al. [16] investigated the LCA of the pre-existing Pine Flat dam, a concrete gravity structure, utilizing the ReCiPe 2016 methodology.