Minimal-waste design of timber layouts from non-standard reclaimed elements: A combinatorial approach based on structural reciprocity

The use of timber allows reducing the environmental impact in the construction sector. However, as the demand for construction timber rises, the pressure on the world’s forest is increasing too. To maintain an adequate supply of timber from sustainable forests in the coming decades, the building industry must adopt practices that reduce the impact on forestry. Reuse is one of the principles of Circular Economy (CE). Among the technical challenges of reuse are the variability and the short size of the stock of elements coming either from demolition or from new construction, such as cut-offs and temporary scaffolding. This work presents a study for the design of structural configurations with short and non-regular sized elements that would normally be considered waste. The configurations are based on the principle of structural reciprocity and are generated by an optimization algorithm that allows minimizing the material waste and maximizing the stock elements use. A computational strategy based on the SPEA-II multi-objective method is employed for the investigation of optimal trade-offs between competing objective functions, such as structural lightness and optimal use of stock inventory. The goal of this work is demonstrating the feasibility of an industrial process, borrowing key elements from the Industry 4.0 paradigm, for a streamlined and economical production of standardized building components using non-standard reclaimed elements.