Optimization based on life cycle analysis for reinforced concrete structures with one-way slabs

• A methodology to find optimal solutions of concrete structures with one-way slabs.
• The optimization model takes into account the environmental impact through LCA.
• Selecting appropriate alternatives allows the designer avoiding unnecessary impacts.
• The columns distribution and the materials used affect the impact of the solution.
• The pretensioned joists option with expanded polystyrene is the best alternative.

This paper proposes a methodology devoted to finding and selecting the optimal solutions of reinforced concrete structures with one-way slabs with regard to the environmental impact caused by the production and building process. The paper analyses each possible alternative depending on the most important variables, such as the structural thickness, the material of the lightening element, and the disposition of columns.This research is based on information from a representative sample of actual structures built for residential use during the last few years in Spain. This information provides data about variables of the problem, the definition of the geometry and the materials used in the different solutions. Once the structural analysis has been developed, the consumption of materials needed to build the structure is recorded, provided that the technical alternative is viable. Through the life cycle analysis (LCA) of the materials and methods used for the implementation of the different alternatives, a comparison is established using the Eco-Indicator ‘99 method.The results show that the number of columns conditions the obtained impacts, and it is worth noting that the least-used option in real residential buildings has very attractive values in terms of environmental impact. The variations obtained in the different alternatives range up to 75%, showing that it is an important factor to consider because a bad choice can lead to a much higher impact. The proposed methodology favours the selection of the alternatives that have less environmental impact.