Moral legitimacy entails intrinsic value and helps executives to convince firm's stakeholders and the general public of the ethical acceptability of an institution or its activities or projects. Social License to Operate (SLO) is the social approval of those affected by a certain business activity, and it is receiving increasing attention, especially in the context of controversial projects such as mining and public works. Moral legitimacy provides ethical support to SLO. Drawing from the Aristotelian-Thomistic tradition and taking substantive justice and the common good of society as the key references, this paper applies the Triple Font of Morality Theory and proposes four criteria which serve to evaluate moral legitimacy: (1) contribution of the project or activity to the common good in a better way than other alternatives (intended end), (2) morality of the means and procedures employed (means elected), (3) ethical evaluation of the situation including stakeholder concerns and needs (concurrent relevant circumstances), and (4) ethical evaluation of reasonably foreseeable consequences associated with the project and how to minimize possible damage or risks, and balance foreseeable negative consequences and benefits. The application of these criteria is illustrated through a project, presented as a case study, which certainly involved controversy and problems with SLO. The project was the construction of a rail tunnel for a high-speed train near the foundations of the Sagrada Familia, the well-known monumental church in Barcelona, Spain.

17Fibre-reinforced concrete (FRC) is a suitable alternative to the traditional reinforced concrete used in the manufacture 28configurations for segmental linings of TBM tunnels using the MIVES method (a multi-criteria decision making 29 approach for assessing sustainability). This MCDM method allows minimising subjectivity in decision making while

The concern for occupational health and safety in construction work is reflected in the many preventive measures taken. However, examples of the systematic assessment of project alternatives aimed at minimizing occupational hazards are rare. This paper proposes a measure of occupational safety (Occupational Risk Index, ORI) that is based solely on the project design and resulting construction process and is a function of the activities carried out and their specific occupational risk (probability and consequences of occurrence). The ORI can thus be used as an indicator to feed multicriteria decision-analysis tools. The proposal is illustrated with a simple example in which two alternatives (one precast and the other constructed in situ) are prioritized in terms of occupational safety, and certain aspects related to redesign are briefly addressed. With the ORI, occupational safety goes from having a passive influence (application to projects that have already been designed) to an active one (influence on the design concept itself) in the design stage of construction projects. The research is based on an analysis of the applicable legislation and interviews with experts.

The research presented in this paper has two main objectives. First, it aims to generate an assessment tool for ranking and selecting the most sustainable domestic waterheating system (WHS) (with the lowest economic, environmental and social impact) that could be applied in any location and with any demand. Second, it aims to ascertain which WHS is the most sustainable in places with a climate and solar radiation like that of Barcelona, Spain, where a minimum solar contribution to domestic water heating is compulsory for new buildings and significant renovations. Multi-criteria decision analysis was employed to create the optimised flexible assessment tool. The Delphi method was followed to perform the surveys, and to provide the objectivity required in the identification of impacts, the definition of indicators and the assignment of weights. The most relevant criteria were determined: annual cost, material consumption, energy consumption, GHG emissions, space requirement, visual impact and occupational risks.The resulting tool was tested by analysing twelve domestic WHS, including two conventional systems, and ten combinations of five solar thermal technologies with two conventional systems as backup for a changing room in a sport centre located in Barcelona. The two conventional WHS studied were a natural gas-fired condensing boiler and an electric water heater. The five solar thermal technologies were: a flat plate with a harp design, a flat plate with a serpentine design, a heat-pipe evacuated tube, a direct-flow evacuated tube, and a direct-flow evacuated tube with CPC. The dynamic thermal simulation programme T*SOL was used to dimension the solar thermal systems. Two sensitivity analyses were carried out: one on weights and one on references. The tool proved very useful in the assessment of these systems, and could also help in decision-making processes to select the most sustainable WHS for other locations and domestic hot water demands.

Fibre-reinforced concrete has been used in structures without any additional reinforcement when the design is determined by transient load stages (precast segments for tunnels), in elements with favourable boundary conditions, and in structures subjected to low load levels (pavements or pipes). Recently, the material has been used as the primary reinforcement in elements with greater structural responsibility, such as building column-supported slabs. Several dozen buildings have incorporated this new technology, and research is being conducted on how to optimise the design whilst guaranteeing the required reliability levels. However, in some cases, fibres have not been used as the primary reinforcement in concrete slabs for economic reasons. In most cases, the solution is compared with existing alternatives (traditionally reinforced concrete) considering only the direct material costs and disregarding indirect costs, social aspects and environmental factors. The building construction sector lacks sustainability rating tools to assess structural components separately (e.g. columns, floors, panels, façades). This paper presents a new method that can be used to assess the sustainability of concrete slabs by means of a multi-criteria decision-making approach including fibre-reinforced concrete. To this end, it uses rigorous analyses of current concrete slab technologies and sustainability assessment tools. Criteria, indicators, weights and value functions have been specifically selected, defined and calibrated for this research.