# Sustainability Enhancement and Evaluation of a Concrete Dam Using Recycling
## 4 Results and Discussion
### Construction Stage
#### 4.1.1 Environmental Impacts
Figure 3: Carbon footprint distribution across different components and processes involved in the production of concrete (kg CO\({}_{2}\) eq). Energy consumption in the project is another key factor, with over 5,700,000 MJ/m of non-renewable energy being consumed, mostly attributed to fuel use and concrete production. Concrete significantly contributes to carcinogens, non-carcinogens, aquatic eutrophication, global warming, and material extraction. Furthermore, the use of wood is associated with deforestation, leading to reduced clean air production and contributing to environmental degradation, particularly affecting land occupation. Table 4 outlines the LCA outcomes for dam construction across four specific categories--human health, ecosystem quality, climate change, and resources--utilizing the IMPACT 2002+ methodology. Furthermore, Figure 5 represents the impact of six key components--concrete, transportation, diesel fuel, wood, blasting materials, and steel and rebar--on these aforementioned categories. Concrete production significantly impacts human health, with the total effect estimated at 0.143 disability-adjusted life years (DALY). This impact arises primarily from emissions during cement production, including particulate matter and pollutants such as nitrogen oxides and sulfur dioxide, which contribute to respiratory and cardiovascular issues. Additionally, the extraction and processing of raw materials, as well as the energy-intensive nature of concrete manufacturing, release greenhouse gases and airborne toxins that further harm air quality and human health. For concrete batching, the DALY primarily stems from air pollution during cement production, including emissions of particulate matter (PM2.5), nitrogen oxides (NOx), and sulfur dioxide (SO\({}_{2}\)). Moreover, the results indicate that, in terms of human health (DALY), the most significant contributors are fuel and concrete, together accounting for a large portion of the impact. Fuel contributes the highest, followed closely by concrete, indicating that energy consumption and emissions from these materials and processes are critical factors affecting human health. Other \begin{table}
\begin{tabular}{c c} \hline \hline
**Damage Category** & **Total** \\ \hline Human health (DALY) & 0.210 \\ Ecosystem quality (PDF m\({}^{2}\) r) & 205,000 \\ Climate change (kg CO\({}_{2}\) eq) & 355 \\ Resources (MJ primary) & 5,700,000 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: LCA results of construction of 1 m width of the dam using the IMPACT 2002+ method. Figure 4: Distribution of environmental impacts during the construction phase of the dam based on the IMPACT 2002+ method. elements like blasting material and transportation also play a role, but are less impactful in comparison. For ecosystem quality (PDF m\({}^{2}\) yr), the most striking result is the overwhelming contribution of blasting materials, which account for the majority of the damage in this category. This suggests that activities related to blasting are highly disruptive to ecosystems, possibly due to habitat destruction. Wood also has a notable impact, likely related to deforestation or land use changes, while other materials like concrete have a much smaller effect on ecosystems. In the climate change (ton CO\({}_{2}\) eq) category, concrete is by far the largest contributor, responsible for the vast majority of carbon emissions. This aligns with the energy-intensive nature of concrete production, particularly in cement manufacturing. Fuel also plays a significant role in emissions, reinforcing the need to address fuel usage to mitigate climate change's impacts. Transportation contributes a smaller but still noteworthy amount of CO\({}_{2}\) emissions. Finally, in the resources (M) primary) category, fuel consumption dominates resource use, indicating a high demand for energy in the processes involved. Concrete follows as the next largest consumer of resources, suggesting that both material production and energy consumption are driving factors in resource depletion.