Among the current targets of the building sector, one major goal is to maximize the resource efficiency (in terms of material use and in terms of energy used to produce the buildings); furthermore, the circular economy model aims for maximizing the reuse of the structural elements; thus, minimizing the material waste and avoiding a second production of elements. The high-rise building sector faces the challenge of considering a design that is flexible and adaptable to meet the functional requirements along its life span; and additionally, to consider a design for deconstruction, where the benefits and challenges that arise form reusing and recycling the material can be considered and addressed from early design stages.
This research addresses these trends and challenges by evaluating and comparing the environmental impact of different structural systems for a high-rise building in the Netherlands (151m). The comparison of four different structural systems with two core variations provides eight different stability systems. The scope of the stability systems considers foundations, core, columns, beams, bracings and floor slabs. The design of the structural systems was performed by the elaboration of 3D FEM models with parametrical tools to ensure the structural safety and serviceability of the building. Furthermore, the assessment of the environmental impact (global warming potential) was performed by means of a Life-Cycle Aseessment comparing three scenarios of the structure: cradle to gate, cradle to cradle, and cradle to cradle with 100% reuse of the structural elements; with data from the Nationale Milieu Database and with information from a technical report from the Joint Research Center.
The analysis of the results demonstrated that the environmental impact of the structural systems with steel core is 21% higher than the one that corresponds to the structures with concrete core, However, this variation is only 4% for the two variants of the diagrid structure. Furthermore, by including the average recycle and reuse rates form the market and current construction practices, the benefits at the end-of-life stage of the building can represent up to 17% of the impacts from the production phase. Moreover, when the reuse rate is considered as 100% the benefits increase up to 42% of the impacts from the production phase.
The results indicate that the improvement of the environmental impact of high-rise buildings can be achieved by means of sustainable structural design from the early phases of the design; where the choice of materials and of the structural system play and important role on the outcome of the total environmental impact of the building, which is becoming an important driver for the decision-making of new projects.