{"id":19494,"date":"2025-01-25T09:50:36","date_gmt":"2025-01-25T09:50:36","guid":{"rendered":"http:\/\/141.23.68.248\/wp\/?page_id=19494"},"modified":"2025-02-10T14:41:08","modified_gmt":"2025-02-10T14:41:08","slug":"4-life-cycle-analysis","status":"publish","type":"page","link":"http:\/\/141.23.68.248\/wp\/?page_id=19494","title":{"rendered":"4. Life-Cycle Analysis"},"content":{"rendered":"

Introduction<\/h1>\n

Life Cycle Analysis (LCA) is used to analyze the integrated context of our vibrant community. It is composed of three main Buildings such as Reinforced Concrete Office Building, Timber Student Dormitory, and Steel Multi-Story Residential Building. These systems have a central Steel-Frame Water Supply Facility that provides a reliable water source for the whole community.<\/span><\/p>\n

The study adopts the LCA methodology, which evaluates the environmental impacts of materials and processes throughout their lifecycle. This method follows the ISO 14040 standards and includes four key phases: defining the goal and scope, creating a lifecycle inventory, assessing lifecycle impacts, and interpreting results.[1]<\/a><\/p>\n

\"process\"<\/a><\/p>\n

 <\/p>\n

Figure 1.\u00a0Life Cycle Framework<\/em><\/p>\n

Scope and Goal<\/h1>\n

The main <\/span>goal <\/b>of this study is to evaluate and compare the environmental impact of these buildings, with a particular focus on <\/span>carbon footprints<\/b> and <\/span>total costs associated with each environmental factor<\/b>.<\/span><\/p>\n

The scope and system boundary is limited to the pre-construction, construction, and operational phases, including raw material extraction, material processing, column fabrication, and operation and maintenance. The end-of-life stages are excluded due to a lack of data and resources. Also, the initial phases have significant environmental impacts and are necessary for identifying sustainable material choices.<\/span><\/p>\n

\"lca-scope-and-boundary\"
\n<\/a><\/p>\n

Figure 2.\u00a0Scope and System Boundary<\/em><\/p>\n

Life Cycle Inventory<\/h1>\n

Table 1.\u00a0Life Cycle Inventory Materials<\/em>\"lcia\"<\/p>\n

Assumptions and Justifications<\/em><\/h2>\n

Emissions (CO\u2082, NOx, SO\u2082): For Reinforced Concrete Office Building, it is known that cement production is the main contributor to the environmental impact of concrete. Aggregates have minimal energy use and emissions, and the impacts of steel reinforcement are included based on the energy. For Steel-Framed Water Supply Facility and the Steel Multi-Story Residential Bulding, the same values were obtained from [2]<\/a>. Lastly, the Timber has a negative carbon emission because wood stores carbon while growing. However, this will still depend on end-of-life treatment like burning or landfilling.
\nThe NOx and SO\u2082 emissions are maily from transportation and processing which are quite low.<\/p>\n

Quantities: Concrete materials are quantified in cubic meters, while the reinforcement is in kg. For Structural steel, it is quantified as kg. Timber is quantified in cubic meters and the steel dowels and bolts for the connections are in kg.<\/p>\n

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Life Cycle Impact Assement<\/h1>\n

Life Cycle Timeline<\/h2>\n

Establishing interventions and lifespan in LCA is important because it creates the sequential framework and scope for evaluating the environmental and economic impacts of the building. Different materials deteriorate at varying rates based on environmental exposure and usage. To ensure that the analysis represents the real-world performance of a material, it is necessary to consider the maintenance, repairs, and replacement.<\/p>\n

Having these interventions visually present will also enable us to see the difference in performance between the materials (RC, Steel, Timber), making it easier to make decisions based on long-term impacts and costs.<\/p>\n

According to Deetman et al. (2020) [3]<\/a>, the overall global estimated lifespan for residential and service-sector buildings is 60 years. Therefore, we set the total lifespan for each building at 60 years, with a strong emphasis on <\/span>preventive maintenance<\/b> to enhance durability, reduce failures, and optimize long-term performance<\/span>.<\/span>
\nDifferent maitenance strategies were analyzed and they can be found here:\u00a0Integrated Maintenance Strategy
\n<\/b><\/strong><\/a><\/p>\n

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Emission Calculation Methodology<\/h2>\n

To determine total emissions, the volumes of key building elements\u2014columns, beams, slabs, and facades\u2014were calculated using the following:<\/p>\n

Table 2. Building Dimensions of the Integrated System<\/em><\/p>\n

\"building-dim\"<\/a><\/p>\n

 <\/p>\n

Weighting is applied to the interventions on the slab and the facade wall to optimize the distribution of these actions based on their impact on the overall system.<\/p>\n

\"weight\"<\/a><\/p>\n

Unit Cost of Energy and Emissions<\/h2>\n

To accurately assess the economic impact of emissions and energy consumption, it is essential to consider the unit costs associated with energy usage and pollutant emissions. These costs reflect the financial burden of environmental impacts, including CO\u2082, NOx, SO\u2082 which contribute to climate change and air pollution. Table 3 provides the unit costs for energy and emissions based on recent European and UK environmental reports:<\/p>\n

Table 3.\u00a0 Unit Cost for Energy and Emissions<\/em><\/p>\n

\"lca-cost\"<\/p>\n

Energy Costs (\u20ac\/MJ):<\/strong> Represents the cost per megajoule of energy used in material production, transport, and construction processes.
\nCO\u2082 Costs (\u20ac\/tonne):<\/strong> The estimated economic impact of CO\u2082 emissions, reflecting carbon pricing mechanisms used to mitigate climate change.
\nNOx & SO\u2082 Costs (\u20ac\/tonne):<\/strong> These pollutants contribute to acid rain and respiratory health issues. The high unit costs reflect the economic damage associated with air quality degradation and environmental remediation efforts.<\/p>\n

Analysis Result and Interpretation<\/h1>\n

Based on the LCI calculations, the total environmental impact is as follows:<\/p>\n

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 <\/p>\n

\"lca-result\"<\/a><\/p>\n

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Figure 3. Total Energy, Emissions, and Cost<\/em><\/p>\n

Interpretation:<\/h2>\n

Negative CO\u2082 emissions resulted to -79,666,834 tonnes\u00a0indicate a significant carbon sequestration effect, primarily due to timber materials. This highlights the environmental benefit of using wood-based construction.<\/p>\n

High NOx (1,489,306 tonnes) and SO\u2082 (646,951.9 tonnes) emissions shows that air pollution impacts must be carefully considered\u00a0especially for steel and concrete-based structures.<\/p>\n

The total cost of \u20ac24.89 million\u00a0shows the aggregated financial burden of energy consumption and pollutant emissions over the building\u2019s life cycle.<\/p>\n

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Impact of Integration on the LCA<\/h1>\n

\"impact\"<\/a><\/p>\n