Basel – Lagerhalle Erlenmatt Ost – Resource assessment of structural components

The Lagerhalle Erlenmatt Ost is a 3-story building (basement, ground floor and two upper floors) used for food storage, located in Erlenmatt district in Basel and erected in 1975. Cast-in-place reinforced concrete (RC) slabs, walls, and mushroom columns form the main load-bearing structure of the building. The self-supporting facade is made of lightweight expanded clay aggregate (LECA) concrete panels. The deconstruction of this building is planned, thus making available a large amount of RC components composing the structure and the facades. Little-known and rarely implemented, the reuse of concrete components from obsolete buildings in new projects is a sustainable approach that promotes a circular economy. When reusing, the components of obsolete buildings are carefully dismantled without being crushed. They are then cleaned, possibly repaired or trimmed, and reassembled with little transformation in a new project, maintaining their shapes and structural properties. In addition to maintaining the embodied energy and history of the reused components, reuse allows the construction industry to reduce demolition waste, greenhouse gas emissions, and material consumption. This report is a preliminary resource assessment and aims at inventorying and assessing all structural components of the Lagerhalle Erlenmatt Ost, focusing on their potential value for reuse. Interest is mainly in the precast LECA concrete facade panels, but cast-in-place RC components are briefly included. The assessment methodology, detailed in a complementary report, allows identifying all properties needed to evaluate the potential for reuse of a RC component: geometry, material properties, resistance, current condition, accessibility, future durability, aesthetics and environmental impacts. After reviewing available reports and drawings on the building, onsite visits are carried out to complete the information and visually inspect the structural components. During the inspection, the components are assessed with regards to their suitability for reuse and their condition is classified into a five-grade scale. The building is made up of approximately 4 700 m3 of material constituting the load-bearing system, with approximately 450 m3 of precast LECA concrete and 4 250 m3 of cast-in-place concrete. The LECA panels are damaged and are assessed as unsuitable for structural reuse. The other components of the building load-bearing structure are considered in good condition by a first preliminary visual inspection. However, they would require further detailed investigations to gather all data needed to plan a potential future reuse. The inventoried components are divided into 5 categories: (1) facade components; (2) slab components; (3) wall components; (4) column components; and (5) staircases. For each of these categories a complete factsheet is prepared, including pictures, drawings and useful information on their condition. The volume and weight of each component types are given, as well as their share of the total material volume. The embodied global warming potential (in kgCO2eq and kWhoil-eq) for fabrication and demolition of the components is also calculated. This document should serve as a base for designing and planning future reuse applications for the concrete components extracted when deconstructing the Lagerhalle Erlenmatt Ost. The information presented here will help planners to prioritize the reuse strategy on the components in the best conditions, with the largest volume share and thus with the largest embodied global warming potential.