Evaluation of Material Recycling Potential within the Structural Systems Life Cycle Assessment (LCA)

Introduction: Energy and resource consumption, environmental emissions, and waste generation are major global challenges. Due to its significant contribution to material consumption, emissions, and waste production, the construction industry plays a critical role in addressing environmental problems. In this context, the study examines the material recycling potential of structural systems, which constitute the largest percentage of a building, within an integrated life cycle and infrastructure perspective.

Methods: An analysis framework for structural systems was developed based on the EN 15978:2011 standard, including the production (A1–A3), construction (A4–A5), end-of-life (C1–C4), and benefits and loads beyond the system boundary (D) modules. The embodied energy and carbon values ​​of steel and reinforced concrete structural systems were analyzed. Material recycling was assessed through an integrated waste management perspective considering recycling and waste storage capacities of a city. Two scenarios were defined: Scenario 1 involves the availability of capacity; scenario 2 involves the lack of capacity for steel. The obtained data were analyzed using a comparison matrix.

Results: For Scenario 1, the steel structure system has an embodied carbon value of 251 kgCO2eq/m² and an embodied energy value of 2309 Mj. The reinforced concrete system has an embodied carbon value of 771 kgCO2eq/m² and an embodied energy value of 1365 Mj. For Scenario 2, the steel structure has an embodied carbon value of 503 kgCO2eq/m² and an embodied energy value of 2618 Mj. While the steel structure shows significantly higher performance in Scenario 1; the reinforced concrete structure becomes comparatively advantageous in Scenario 2.

Conclusions: Material recycling potential is a multifaceted and important sustainability criterion that directly affecting the environmental performance of a building component. Within the LCA framework, a city’s recycling and waste storage capacities can create significant environmental impacts and should therefore be evaluated through an integrated approach.