{"id":25636,"date":"2026-02-05T00:34:42","date_gmt":"2026-02-05T00:34:42","guid":{"rendered":"http:\/\/141.23.68.248\/wp\/?page_id=25636"},"modified":"2026-02-07T20:54:32","modified_gmt":"2026-02-07T20:54:32","slug":"building","status":"publish","type":"page","link":"http:\/\/141.23.68.248\/wp\/?page_id=25636","title":{"rendered":"Building"},"content":{"rendered":"\n

Introduction<\/strong><\/p>\n\n\n\n

In commercial buildings dominated by reinforced concrete systems, beam design strongly influences embodied energy and environmental emissions. Within this context, this assignment compares three beam design options: reinforced concrete, steel, and engineered timber, under identical structural conditions. Environmental performance is evaluated using life-cycle indicators (energy consumption, CO\u2082, NOx, SO\u2082), and the Analytic Hierarchy Process (AHP) is applied to rank the alternatives and identify the most sustainable beam option.<\/p>\n\n\n\n

Goal and Scope<\/strong><\/p>\n\n\n\n

The goal of this assessment is to compare the environmental performance of three beam design options and support sustainable material selection at the component level. The analysis focuses exclusively on the beam element, with all alternatives assumed to provide equivalent structural performance.<\/p>\n\n\n\n

The system boundary covers material extraction and production, transport to site, construction, and maintenance over a 50-year service life. Operational energy use and end-of-life processes are excluded to maintain consistency across the compared beam designs and to reflect the component-level focus of the study.<\/p>\n\n\n

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Figure 1. System Boundary of the study<\/em><\/figcaption><\/figure><\/div>\n\n\n

Design Options<\/strong><\/p>\n\n\n\n

Design Option<\/strong><\/td>Beam Type<\/strong><\/td>Cross-Section<\/strong><\/td>Material<\/strong><\/td><\/tr>
Option 1<\/td>Reinforced Concrete (RCC)<\/td>400 \u00d7 600 mm<\/td>C37 concrete, reinforced<\/td><\/tr>
Option 2<\/td>Steel Beam<\/td>IPE 300<\/td>Structural steel (S355)<\/td><\/tr>
Option 3<\/td>Timber Beam<\/td>440 \u00d7 800 mm<\/td>Glulam (GL24h)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Table 1: Design Options and its parameters for Life Cycle Inventory Analysis<\/em><\/p>\n\n\n

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Figure- Design option 1: RCC beam<\/em><\/figcaption><\/figure><\/div>\n\n
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Figure- Design option 2: Steel Beam<\/em><\/figcaption><\/figure><\/div>\n\n
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Figure- Design option 3: Timber Beam<\/em><\/figcaption><\/figure><\/div>\n\n\n

Life cycle Inventory Analysis<\/strong><\/p>\n\n\n\n

Material<\/td>Scope<\/td>QuantitiesKg\/m3<\/sup><\/td>Energy(MJ\/t)<\/td>CO2<\/sub> (kg\/kg)<\/td>NOX<\/sub> (kg\/kg)<\/td>SO2<\/sub> (kg\/kg)<\/td><\/tr>
Cement (grade 42)<\/td>RCC<\/td>3150<\/td>4.325<\/td>0.819<\/td>0.177<\/td>0.065<\/td><\/tr>
Coarse Aggregates<\/td>RCC<\/td>1050<\/td>0.0035<\/td>0.016<\/td>0.0018<\/td>0.0018<\/td><\/tr>
Fine Aggregates<\/td>RCC<\/td>750<\/td>0.0023<\/td>0.0053<\/td>0.009<\/td>0.009<\/td><\/tr>
Reinforcement Steel (500 Mpa)<\/td>RCC<\/td>250<\/td>2430<\/td>1.85<\/td>0.71<\/td>1.85<\/td><\/tr>
Formwork<\/td>RCC<\/td>30<\/td>5<\/td>0.2<\/td>0.05<\/td>0.01<\/td><\/tr>
Structural Steel (S355)<\/td>SB<\/td>7850<\/td>2430<\/td>1.85<\/td>0.71<\/td>1.85<\/td><\/tr>
Protective Coating (Epoxy\/Zinc)<\/td>SB<\/td>50<\/td>110<\/td>3.1<\/td>0.12<\/td>0.02<\/td><\/tr>
Engineered Timber (Glulam GL24h)<\/td>TB<\/td>420<\/td>11<\/td>0.23<\/td>0.12<\/td>0.02<\/td><\/tr>
Steel Connectors\/ Dowels<\/td>TB<\/td>25<\/td>2430<\/td>1.85<\/td>0.71<\/td>1.85<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Table 2: Life Cycle Inventory of materials<\/em><\/p>\n\n\n\n

Cement and reinforcement steel dominate CO\u2082 emissions and energy demand in the reinforced concrete and steel beams. Timber beams show lower overall impacts, and the inventory data are sourced from \u00d6KOBAUDAT and certified Environmental Product Declarations (EPDs).<\/p>\n\n\n\n

Interventions for Structural Beams<\/strong><\/p>\n\n\n\n

A 50-year life cycle is assumed for all beam options, with maintenance, repair, and replacement intervals defined based on material-specific durability. Reinforced concrete beams follow inspection and mid-life repair intervals from Chen et al. (2021), steel beam interventions are based on corrosion behavior from Borgioli (2023), and timber beam maintenance reflects sensitivity to moisture and biological decay. These intervention schedules are applied consistently to generate the life-cycle timelines.<\/p>\n\n\n\n

Design Option<\/td>Event<\/td>Frequency<\/td>Total Lifespan(years)<\/td><\/tr>
RCC Beam<\/td>M<\/td>10<\/td>50<\/td><\/tr>
RCC Beam<\/td>R<\/td>25<\/td>50<\/td><\/tr>
RCC Beam<\/td>RP<\/td>50<\/td>50<\/td><\/tr>
Steel Beam<\/td>M<\/td>5<\/td>50<\/td><\/tr>
Steel Beam<\/td>CRS<\/td>8<\/td>50<\/td><\/tr>
Steel Beam<\/td>PR<\/td>20<\/td>50<\/td><\/tr>
Steel Beam<\/td>RP<\/td>50<\/td>50<\/td><\/tr>
Timber Beam<\/td>M<\/td>5<\/td>50<\/td><\/tr>
Timber Beam<\/td>R<\/td>20<\/td>50<\/td><\/tr>
Timber Beam<\/td>RP<\/td>50<\/td>50<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Where, M = Maintenance, R = Repair, RP = Replacement, PR = Partial Replacement, CRS= Coating Renewal for Steel<\/p>\n\n\n\n

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Life Cycle Cost Analysis<\/strong><\/p>\n\n\n\n

The reinforced concrete beam shows the lowest life-cycle cost, while the steel beam is the most expensive due to higher material, construction, and maintenance costs.<\/p>\n\n\n

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Fig 7: Visualization of total life-cycle costs of different beam types obtained from R<\/em><\/figcaption><\/figure><\/div>\n\n\n

Results and Discussions<\/strong><\/p>\n\n\n\n

1.Total Energy Consumption and Emissions of Each Beam System<\/p>\n\n\n\n