Amro Nasr

Recent studies suggest that concrete creep may be further exacerbated by climate change. However, up to now this effect has not been quantified in literature. The current study addresses this gap and presents a probabilistic approach for quantitatively assessing this effect. For this purpose, five different stochastic creep models (i.e. Model Code 1999, Model Code 2010, B3, B4, and B4s models) are used under considerations of the historical and future climatic conditions in Sweden to assess the long-term creep coefficient and the subsequent stress redistribution of an axially loaded column. While some creep models show similar percentage increases in the long-term creep coefficient in all Swedish counties, other creep models show higher percentage increase values for northern than for southern counties. The highest increase in the end-of-century creep coefficient is found using models B4 and B4s (e.g. over 40% increase is possible for northernmost Sweden, i.e. Norrbotten county, under RCP8.5). Furthermore, the current article also shows that the end-of-century creep coefficient is more sensitive to uncertainties not related to the climate (i.e. parameter and creep modelling uncertainties) than to climate uncertainty.

The impact of climate change on the deterioration of reinforced concrete elements have been frequently highlighted as worthy of investigation. This article addresses this important issue by presenting a time-variant reliability analysis to assess the effect of climate change on four limit states; the probabilities of corrosion initiation, crack initiation, severe cracking, and failure of a simply supported beam built in 2020 and exposed to chloride-induced corrosion. The historical and future climate conditions (as projected by three different emission scenarios) for different climate zones in Sweden are considered, including subarctic conditions where the impact of climate change may lead to large increases in temperature. The probabilities of all limit states are found to be: 1) higher for scenarios with higher GHG emissions and 2) higher for southern than for northern climate zones. However, the end-of-century impact of climate change on the probabilities of reaching the different limit states is found to be higher for northern than for southern climate zones. At 2100, the impact of climate change on the probability of failure can reach up to an increase of 123% for the northernmost zone. It is also noted that the end-of-century impact on the probability of failure is significantly higher (ranging from 3.5–4.9 times higher) than on the other limit states in all climate scenarios.

Climate change can substantially affect infrastructure performance and safety. In this article, the impact of climate change on fungal decay of wooden infrastructure in ground contact is investigated. For this purpose, projections of three different climate change scenarios are used to assess the impact of climate change on fungal decay rate of untreated clear wood elements in ground contact in Sweden. The highest increase in the average decay rate is observed for four counties located in mid-Sweden, i.e. Örebro, Värmland, Västmanland, and Gävleborg. Furthermore, two illustrative examples are presented to demonstrate the impact of the increased decay rates on the structural performance and long-term reliability of timber elements in four selected counties, Skåne (southernmost Sweden), Örebro, Värmland, and Västmanland. In the first illustrative example, the impact of climate change on the bending moment capacity of untreated timber utility poles is assessed while in the second the impact on the long-term reliability of axially loaded untreated columns is investigated. In the four studied counties, it is found that climate change can have considerable impacts on the structural performance and long-term reliability of timber elements in ground contact.

Recent studies have identified many potential climate change impacts on bridges. Considering the sheer number of these potential impacts, how can a bridge owner prioritise which impacts to consider, and for which bridges? This paper proposes a risk-based multi-criteria decision analysis method for systematically addressing these two questions simultaneously. The proposed method can be used to address both extreme and non-extreme impacts as opposed to focussing solely on extreme impacts as has been done in previous prioritisation studies related to climate change risks. The proposed method is based on four main components of risk: hazard, impact, vulnerability and consequences. Several indices characterising these components are used to address the previous two questions. To reflect the uncertainty in the analysis, the different indices are assessed optimistically and pessimistically. Additionally, to ensure a more transparent decision-making process the inclusion of a strength of evidence assessment is also proposed. The applicability of the method is then demonstrated on three illustrative case studies for three different potential climate change impacts. It is concluded that the proposed method is both feasible and appropriately fulfils its purpose. Nevertheless, the proposed method should be more elaborately tested on practical bridge case studies to further establish its applicability.

The potential risks of climate change on the built environment involve large uncertainties. This poses an intricate problem to designers and challenges a long-standing tradition of built infrastructure design. More specifically, designers are faced with this challenging question: how to rationally account for climate change risks when designing a new asset? A framework that holistically addresses this difficult question is missing from the current literature. This study contributes to this gap by (1) proposing a conceptual framework for rationally considering the effects of climate change in the design of these assets and (2) identifying the challenges that need to be overcome to facilitate the transition, and further development, of the proposed framework into practice. First, a detailed overview of important infrastructure performance requirements that are relevant to the proposed framework is presented. The different stages of the proposed conceptual framework are then outlined. The proposed framework progresses in the following order: ranking the importance of the asset, identifying the potential climate change risks, analyzing these risks, selecting a design strategy, and finally evaluating the final design. Lastly, several challenges that impede the application of the proposed framework in practical settings are identified. The proposed conceptual framework and the identified challenges comprise a necessary steppingstone towards addressing this pressing issue and developing a more practically applicable framework for considering the risks of climate change in the design of built infrastructure assets.

Climate change may have multifaceted impacts on the safety and performance of infrastructure. Accounting for the different ways in which potential climate change scenarios can affect our infrastructure is paramount in determining appropriate adaptation and risk management strategies. Despite gaining some attention among researchers in recent years, this research area is still largely uninvestigated. Several studies have indicated bridges to be especially susceptible to the effects of climate change. This article presents the potential impacts of climate change on bridges and combines the findings of close to 70 research articles to construct a broad list of their possible adaptation techniques. Although this study focuses on bridges, many of the presented climate change impacts and their adaptations are of relevance also to other types of infrastructure.

An overabundance of evidence, both observational and from model projections, indicate that changes to the climate system are taking place at unprecedented rates. Although the magnitudes of these changes involve large uncertainties, the fact that our climate is changing is unequivocal. To ensure an unimpaired functionality of our societies,it is therefore of crucial importance to study the potential climate change impacts on infrastructure. Taking into account that bridges have a considerably long service life, it is of direct relevance to ascertain their reliable performance against climate change risks. This paper synthesizes the findings of over 190 research articles to identify the potential risks climate change may pose on bridges. Over 30 potential risks, supported by pertinent previous bridge damage (or failure) cases, are identified, categorized, and linked to the projected future climate changes. The identified risks can be used as a basis for future risk prioritization by bridge managers.