No abstract

Highway infrastructure represents a significant part of the public assets, and through its lifetime, is exposed to various deterioration processes leading to the depreciation of its value. It is therefore of vital importance to manage these assets aiming to reduce the loss of their value with time to a minimum. A typical task of road managers is making decisions related to maintenance, repair and rehabilitation based on data regarding the existing condition, risk of its use, life cycle costs and age. Road infrastructure is complex, and therefore the optimal choice of planned interventions is a delicate task often left to the road managers' subjective judgment. The main goal of research work presented in the paper is the development of a multiple criteria decision support system to determine the priority ranking of asset rehabilitation projects. Results are presented for a selected case study that consists of 27 overpasses for a highway section. The data on the condition of crossovers obtained by regular inspection along their contribution to a structured database are essential. The selection of the set of asset rehabilitation projects is carried out by using the developed decision support system that includes the budget constraint option. The selected set of asset maintenance/rehabilitation projects meets best the pre-defined combination of several criteria and therefore yields the maximized overall benefit. The results showing the selection criteria employed in the decision process and relative importance are crucial in obtaining the targeted goals. The selected criteria should therefore reflect the needs of the users and the actual conditions related to the assets.

In today’s world, the definition of quality has been extended to more comprehensive level, which also comprises sustainable performance. The paper systematically builds an integrated model that includes quality as well as sustainable performance of the built environment and accompanying construction processes. This model for the “Integrated Quality and Sustainability Performance Assessment in Construction” presents a three-level arrangement, namely: the structure, process/ project, and construction product. We propose a holistic sustainability assessment methodology based on the authors’ previous research work for structures. The strict implementation of quality and environmental management systems in the participating organisations and in the whole construction project guarantees quality and environmental performance at project/process level. On the construction product level, we complement the existing requirement of providing a statement of conformity for each product of the structure with the Environmental Product Declaration (EPD) for all construction products. We use the Life Cycle Assessment (LCA) methodology to obtain the EPDs for specific construction products; in this way, we can evaluate their environmental impacts throughout the life cycle of a product or structure. On the structure level, a model for the integrated sustainability and quality assessment, which was previously proposed by the authors, is employed. Integration of all three levels ensures that the desired plateau of quality and sustainability performance is achieved for structures, processes and products. In the present version, the model is tailored to the specific features of buildings, and the sustainability aspect is limited to the environmental performance. An investigation of measures required to implement the proposed model into practice shows that clients have a major influence upon the procurement rules. Consequently, the targeted audience of potential users is that of clients procuring buildings.