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1.	Sundell, Jonas, 1984, et al. (författare) Comprehensive risk assessment of groundwater drawdown induced subsidence 2019 Ingår i: Stochastic Environmental Research and Risk Assessment. - : Springer Science and Business Media LLC. - 1436-3240 .- 1436-3259. ; 33:2, s. 427-449 Tidskriftsartikel (refereegranskat)abstract © 2019, The Author(s). We present a method for risk assessment of groundwater drawdown induced land subsidence when planning for sub-surface infrastructure. Since groundwater drawdown and related subsidence can occur at large distances from the points of inflow, the large spatial extent often implies heterogeneous geological conditions that cannot be described in complete detail. This calls for estimation of uncertainties in all components of the cause-effect chain with probabilistic methods. In this study, we couple four probabilistic methods into a comprehensive model for economic risk quantification: a geostatistical soil-stratification model, an inverse calibrated groundwater model, an elasto-plastic subsidence model, and a model describing the resulting damages and costs on individual buildings and constructions. Groundwater head measurements, hydraulic tests, statistical analyses of stratification and soil properties and an inventory of buildings are inputs to the models. In the coupled method, different design alternatives for risk reduction measures are evaluated. Integration of probabilities and damage costs result in an economic risk estimate for each alternative. Compared with the risk for a reference alternative, the best prior alternative is identified as the alternative with the highest expected net benefit. The results include spatial probabilistic risk estimates for each alternative where areas with significant risk are distinguished from low-risk areas. The efficiency and usefulness of this modelling approach as a tool for communication to stakeholders, decision support for prioritization of risk reducing measures, and identification of the need for further investigations and monitoring are demonstrated with a case study of a planned railway tunnel in Varberg, Sweden.
2.	Sundell, Jonas, 1984, et al. (författare) Economic valuation of hydrogeological information when managing groundwater drawdown 2019 Ingår i: Hydrogeology Journal. - : Springer Science and Business Media LLC. - 1431-2174 .- 1435-0157. ; 27:4, s. 1111-1130 Tidskriftsartikel (refereegranskat)abstract © 2019, The Author(s). A procedure is presented for valuation of information analysis (VOIA) to determine the need for additional information when assessing the effect of several design alternatives to manage future disturbances in hydrogeological systems. When planning for groundwater extraction and drawdown in areas where risks—such as land subsidence, wells running dry and drainage of streams and wetlands—are present, the need for risk-reducing safety measures must be carefully evaluated and managed. The heterogeneity of the subsurface calls for an assessment of trade-offs between the benefits of additional information to reduce the risk of erroneous decisions and the cost of collecting this information. A method is suggested that combines existing procedures for inverse probabilistic groundwater modelling with a novel method for VOIA. The method results in (1) a prior analysis where uncertainties regarding the efficiency of safety measures are estimated, and (2) a pre-posterior analysis, where the benefits of expected uncertainty reduction deriving from additional information are compared with the costs for obtaining this information. In comparison with existing approaches for VOIA, the method can assess multiple design alternatives, use hydrogeological parameters as proxies for failure, and produce spatially distributed VOIA maps. The method is demonstrated for a case study of a planned tunnel in Stockholm, Sweden, where additional investigations produce a low number of benefits as a result of low failure rates for the studied alternatives and a cause-effect chain where the resulting failure probability is more dependent on interactions within the whole system rather than on specific features.
3.	Adam, Abderisak, 1988, et al. (författare) How task heterogeneity and frequency relates to knowledge codification: Evaluating the Shared Construction Guidelines (SCG) of 24 Swedish Public Client Organizations 2017 Ingår i: 9th Nordic Conference on Construction Economics and Organization. ; , s. 1-9 Konferensbidrag (refereegranskat)abstract Over a sustained period of time, organizational theorists have argued that public sector organizationsare more inefficient than their private counterparts. Recent studies have explained these inefficienciesas the result of having to do with capabilities rather than resources thereby calling for an improvementof the capabilities of public organizations. A key mechanism for achieving such improvements is thearticulation and codification of knowledge. This study examines an attempt at codifying knowledge inthe form of a set of shared construction guidelines (SCG) employed by 24 large public clientorganizations in the Municipality of Gothenburg, Sweden. Specifically, these guidelines are viewedwith respect to the framework of Zollo and Winter (2002) in terms of how organizations with high taskheterogeneity and low task frequency can more effectively develop dynamic capabilities through thedeliberate learning mechanism of knowledge codification. Preliminary results indicate that taskfrequency and organizational size are stronger indicators than heterogeneity in deciding whether apublic client organization utilizes knowledge codification systems such as the SCG.
4.	Adam, Abderisak, 1988 (författare) Managing construction challenges: Viability of a dynamic capabilities approach for the public client 2016 Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract Construction clients in the public sector face a large number of challenges in designing, procuring and managing construction projects in a manner that is conducive to the organization’s overall goals. In particular, clients have faced challenges in delivering projects that satisfied the projects’ goals with respect to cost overruns, delays and sustainable construction. The role of the client in managing these challenges has more recently been emphasized with a growing number of studies and governmental reports calling for the development of the client’s capabilities.This thesis examines the capabilities of the construction client through a dynamic capabilities framework, particularly with respect to the activities of sensing, seizing and transforming. Furthermore, the thesis explores whether the concept of dynamic capabilities is a viable approach for understanding how to manage the clients’ capabilities in a way that ensures that construction-related challenges are addressed. The thesis is based primarily on a case study of a large public construction client located in Sweden.Findings are presented in three appended papers. The thesis concludes with a discussion on the viability of using a dynamic capabilities framework in the specific case described in this thesis. It is argued that the concept of dynamic capabilities is inadequate for capturing the specific context in which public client organizations operate. Suggestions for alternative approaches to understanding the management and development of capabilities are then discussed.
5.	Williams Portal, Natalie, 1986, et al. (författare) Bending behaviour of novel Textile Reinforced Concrete-foamed concrete (TRC-FC) sandwich elements 2017 Ingår i: Composite Structures. - : Elsevier BV. - 0263-8223 .- 1879-1085. ; 177, s. 104-118 Tidskriftsartikel (refereegranskat)abstract A novel sandwich element design consisting of two facings made of carbon reinforced Textile Reinforced Concrete (TRC), a low density foamed concrete (FC) core and glass fibre reinforced polymer (GFRP) connecting devices was experimentally investigated according to quasi-static and cyclic quasi-static four-point bending. Optical measurements based on Digital Image Correlation (DIC) were taken during testing to enable a detailed analysis of the bending behaviour and level of composite action. A model, verified by the experiments, was developed based on non-linear finite element analysis (NLFEA) to gain further insight on the failure mechanisms. Under both loading conditions, the bending behaviour of the TRC-FC composite elements was characterized by favourable load bearing capacity, partial composite action, superior ductility and multiple fine cracking. The connecting devices were found to be the critical elements causing the initial failure mechanism in the form of localized pull-out within an element.
6.	Adl-Zarrabi, Bijan, 1959, et al. (författare) Safe and Sustainable Coastal Highway Route E39 2016 Ingår i: Transportation Research Procedia. - : Elsevier BV. - 2352-1465 .- 2352-1457. ; 14, s. 3350-3359 Konferensbidrag (refereegranskat)abstract The project “Coastal Highway Route E39” have a mandate to, investigate how infrastructure can exploit renewable energy to reduce environmental footprint. Three PhD projects were initiated on this subject at Chalmers University of Technology by Norwegian public road administration. Results in this paper conclude that (1) Life Cycle Assessment should have a geographical dimension with respect to assumptions and input data, (2) there are substantial potential to reduce the CO2 emissions from the E39, especially when considering an electrification, and (3) the harvested energy from hydronic pavement system can be enough for maintaining ice-free roads in Nordic countries.
7.	Dymitrow, Mirek, et al. (författare) Crossing dichotomies and breaking mental patterns: Green business development when all else fails? 2017 Ingår i: 8th International Scientific Conference “Rural Development 2017: Bioeconomy Challenges”, 23–24 November, 2017 Kaunas, Lithuania. Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Obtaining sustainable and inclusive societal organization is not merely a simple matter of ‘doing it’ by subscribing to some winning formula. Given that conceptual frameworks always guide our thoughts, judgments and actions (Latour, 2013; Harvey, 1996; Dennett, 1993), the ways in which we relate to concepts chosen to serve as guiding forces for future development will eventually determine its outcome. As scholarly evidence continuously suggests the concepts ‘rural’ and ‘urban’ are increasingly recognized as artificial barriers for conducting sound and integrated development endeavors in a globalized reality of interconnectedness. In line with the Sustainable Development Goals, which aim to eradicate poverty, shield the planet and safeguard prosperity for all, commitment to universal access to healthy food year round has become an important agenda point. This, however, has been exacerbated by binary thinking and separate ways of doing policy. This paper aims to share experiences from a unique project launched in the northern parts of Gothenburg, Sweden’s second largest city. While the area offers ample resources and immense opportunities for areal economies, it at the same time remains one of Gothenburg’s most segregated, with high levels of unemployment, ill health and crime. The uniqueness of the project lies not only in its way of abridging the rural-urban divide, but also by consciously deferring from the debilitating rhetoric of previous ‘immigrant policies’, and instead focusing on agricultural productivity, small-scale food producers and sustainable food strategies. Such exhortations to bridge between philosophical and material polarities, however, have not come without conceptual and practical challenges, something this paper aims to subsume and open up to debate.
8.	Crocetti, Roberto, et al. (författare) Stress-laminated-timber decks: state of the art and design based on Swedish practice 2016 Ingår i: European Journal of Wood and Wood Products/Holz als Roh - und Werkstoff. - : Springer Science and Business Media LLC. - 1436-736X .- 0018-3768. ; 74:3, s. 453-461 Tidskriftsartikel (refereegranskat)abstract Stress-laminated-timber (SLT) bridge decks area valid alternative to conventional short- and medium-spanbridges in terms of cost and performance. SLT decks aremade from a number of planks or glulam beams positionedside by side and stressed together using high-strength steelbars. A concentrated load can therefore be distributed fromthe loaded beams onto adjacent beams due to the resistingfriction caused by the pre-stressing of all beams in thedeck. This paper describes the state of the art of SLT bridgedecks, with special emphasis on Swedish practice. Theeffect of butt joints on deck deflection and solution appliedto accommodate the loss of pre-stress are shown. Simpledesign tools for the preliminary design of road bridges areillustrated. Best practice with regard to some detailing,water protection and durability is also discussed. Finally,possible developments of SLT bridges are discussed.
9.	Kharazmi, Parastou, 1977- (författare) Monitoring quality of sewer renewal using polymeric systems in Sweden- data set 2019 Annan publikationabstract This data set includes data to support research findings stated in the article: Monitoring quality of waste-water sewer pipe rehabilitations using polymeric systems
10.	Kharazmi, Parastou, 1977- (författare) Experimental evaluation of a rubber-epoxy polymeric system used in the rehabilitation of sewer infrastructure- Dataset 2019 Annan publikationabstract This dataset includes data related to water sorption analyses to support research findings stated in the article:"Experimental evaluation of a rubber-epoxy polymeric system used in the rehabilitation of sewer infrastructure: a case study in Sweden" with the following abstract: One rehabilitation method used mainly for wastewater sewers in residential buildings involves applying a rubber-epoxy composite to the inner surface of the aged pipeline. In order to understand the material’s performance and stability in operation, during which it is constantly exposed to deteriorative factors, the properties of the material were studied in the laboratory under artificial water and air aging conditions. Changes in the material were monitored by means of tests such as thermal analyses, mechanical testing and water absorption assessment.
11.	Mathern, Alexandre, 1986, et al. (författare) Experimental study of time-dependent properties of a low-pH concrete for deposition tunnels 2018 Ingår i: fib Symposium. - 2617-4820. ; , s. 1726-1735 Konferensbidrag (refereegranskat)abstract The Swedish Nuclear Fuel and Waste Management Company developed a method for the final disposal of canisters for spent nuclear fuel in tunnels at depths of about 500 meters. The concept for closure of the deposition tunnels is based on a bentonite seal supported by a spherical concrete dome structure. In order to fulfil the requirements specific to the repository concept, a special mix of low-pH self-compacting concrete was developed. A series of large-scale castings and laboratory tests were conducted to gain experience on this low-pH concrete mix, in conjunction with the full-scale demonstration test of an unreinforced concrete dome plug in the underground hard rock laboratory in Äspö, Sweden. The laboratory tests aimed at studying the creep properties under high sustained compressive stresses of the low-pH concrete mix, its shrinkage properties and the properties of the rock-concrete interface. This paper provides an overview of these tests and analyses the latest results of the recently completed creep tests, which include 6 years of measurements. These results allow to improve understanding of the structural behaviour of the concrete plug and to assess the effects of the very high pressure acting on the plug on its deformations, cracking and water tightness.
12.	Rempling, Rasmus, 1976, et al. (författare) Research Roadmap - Information Integration in Construction 2019 Rapport (övrigt vetenskapligt/konstnärligt)abstract This Roadmap is developed for a challenging Global environment where fundamental paradigms such as data generation and analysis, are shifting at a seismic rate, while change in Construction Industries across the Globe is, in the main, confined to large-scale projects and slow. Against this background, the authors set out to also give a ‘voice’ to small-to-medium scale projects through which the construction output Worldwide is delivered. Hence, project scale was one of the key considerations throughout this Roadmap. Moreover, the authors conceptualized data integration by taking the realities of doing business’ in construction into consideration. The emergent framework facilitates the discussion of knowledge and data integration at organisational, team, operational and technical levels across key project phases. This approach recognizes that business is done through projects but change can only come about if appropriate organizational structures and processes are put in place. Last, but not least, the authors strived to ensure that data integration was not considered solely from a technical perspective. Organisational, team and individual aspects of data integration were integrated in the research framework. Through our work the individual’s willingness to collaborate emerged as a critical driver for high levels of integration, while our survey did identify “Reluctance to work across professional boundaries” as a major barrier to integration. Hence, we conclude that research on integration should pay due attention to the individual.
13.	Aygül, Mustafa, 1970, et al. (författare) A comparative study of different fatigue failure assessments of welded bridge details 2013 Ingår i: International Journal of Fatigue. - : Elsevier BV. - 0142-1123. ; 49:0, s. 62-72 Tidskriftsartikel (refereegranskat)abstract Five different welded joints frequently used in steel bridges have been selected to investigate the accuracy and applicability of three fatigue assessment methods. The first method, also categorised as the global method, is the nominal stress method, while the more advanced methods are the hot spot and the effective notch stress methods. Solid element based finite element models for welded bridge details were created by following the modelling requirements of each fatigue assessment method. A statistical evaluation based on the results of the finite element analyses and the fatigue test data collected from the literature was performed to determine the mean and characteristic fatigue strength. In addition, the standard deviation for each data series was also determined to conclude how well each method describes the fatigue strength of each welded detail. A method with a lower standard deviation is regarded as more accurate. Moreover, the evaluated results from each method were compared with the recommended fatigue strength values in the Eurocode 3 (EN 1993-1-9:2005) and IIW codes. In the light of the test results in this study, it appears that the codes are in reasonable agreement with the test data, even though a few examples of the opposite occurred. The conclusion based on the revised results in this article indicates that the nominal stress method yields satisfactory results, despite its simplicity. When considering the effort involved in creating FE models for numerical analysis, it seems clear that the choice of the nominal method is fairly acceptable.
14.	Blomfors, Martin, et al. (författare) Reliability analysis of corroded reinforced concrete beam with regards to anchorage failure 2019 Ingår i: Life-Cycle Analysis and Assessment in Civil Engineering. - : CRC Press/Balkema. - 9781138626331 - 9781351857574 ; , s. 337-344, s. 337-344 Konferensbidrag (refereegranskat)abstract Reinforcement corrosion is a common problem in reinforced concrete infrastructure today, and it is expected to increase in the future. To simply replace the corroded structures with new ones requires large resources, both in financial and environmental terms. Therefore it is important that existing structures are used to their full potential, also after the onset of corrosion. This paper presents a reliability study of the anchorage capacity of a reinforced concrete beam including reinforcement corrosion. The sensitivity of the different input parameters is also studied. As expected, the results show that the reliability is reduced with corrosion; the magnitude depends to a large extent on the modelling uncertainty used for the bond model for corroded reinforcement. The sensitivity analysis shows an influence of corrosion also on the sensitivities of the input parameters, which is expected based on the properties of the underlying bond model. This paper demonstrates that probabilistic evaluations give valuable insight of the reliability, which can be used to prolong the service-life of existing infrastructure and save both money and the environment.
15.	Stojanovski, Todor, 1976- (författare) The Morphological Effect of Public Transportation Systems on Cities : Urban Analysis of Transit-Oriented Development (TOD) in Swedish Cities 2015 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
16.	Adam, Abderisak, 1988, et al. (författare) Aggregation of factors causing cost overruns and time delays in large public construction projects: Trends and implications 2017 Ingår i: Engineering, Construction and Architectural Management. - 1365-232X .- 0969-9988. ; 24:3, s. 393-406 Tidskriftsartikel (refereegranskat)abstract PurposeThe purpose of this paper is to explore the impact that cost overruns and time delays exert on large public construction projects to clarify how past and current research regard factors causing cost overruns and time delays in large public construction projects.Design/methodology/approachThis paper, which is based on an analysis of a literature selection consisting of 40 journal articles, investigates and ranks the occurrence of and the explanations for cost overruns and time delays in large public construction projects. The study makes use of a kiviat diagram/radar chart in order to visualize multivariate data.FindingsAggregated rankings of important causes of cost overruns and time delays are reported. These show a strong emphasis on the management aspect as a primary cause of cost overruns and delays. Additionally, there seems to be a trend toward deemphasizing the role of financial considerations in explaining cost overruns and delays. It is argued that there needs to be a more rigorous assessment of the impact that each factor has on cost increases and delays based on factual observed data as opposed to retrospective accounts from questionnaire respondents.Research limitations/implicationsOnly public construction projects have been considered. The results will not be directly applicable to privately funded construction projects and/or projects of a smaller size.Originality/valueThe use of trend data, as illustrated in a kiviat diagram, showing how different ranking factors causing cost overruns and time delays has changed in importance over time.
17.	Adam, Abderisak, 1988, et al. (författare) Applying the dynamic capabilities framework in the case of a large public construction client 2017 Ingår i: Construction Management and Economics. - : Informa UK Limited. - 1466-433X .- 0144-6193. ; 35:7, s. 1-12 Tidskriftsartikel (refereegranskat)abstract Public clients in the construction sector face a number of challenges in designing, procuring and managing major construction projects. The client’s role in bringing about project delivery has more recently been emphasized, particularly with respect to developing capabilities that facilitate the coordinating of projects through its different phases. In line with these developments, this paper sets out to examine the management of capabilities in a client organization through the lens of the dynamic capabilities framework. In particular, what is investigated is how the client organization senses, seizes and transforms opportunities. In pursuit of this objective, an exploratory case study approach is adopted which examines one of Sweden’s largest public client organizations. The study explores the concept of dynamic capabilities and its applicability to the public construction context. Although the usefulness of dynamic capabilities as an interpretive framework is recognized, it is suggested that the concept of dynamic capabilities is inadequate for addressing the specific context in which public client organizations operate. Particularly with respect to the project-based characteristic of these organizations and the difficulty in framing what constitutes “competitive advantage” for public organizations.
18.	Haghani Dogaheh, Reza, 1979, et al. (författare) Fatigue-Prone Details in Steel Bridges 2012 Ingår i: Buildings. - : MDPI AG. - 2075-5309. ; 2:4, s. 456-476 Tidskriftsartikel (refereegranskat)abstract This paper reviews the results of a comprehensive investigation including more than 100 fatigue damage cases, reported for steel and composite bridges. The damage cases are categorized according to types of detail. The mechanisms behind fatigue damage in each category are identified and studied. It was found that more than 90% of all reported damage cases are of deformation-induced type and generated by some kind of unintentional or otherwise overlooked interaction between different load-carrying members or systems in the bridge. Poor detailing, with unstiffened gaps and abrupt changes in stiffness at the connections between different members were also found to contribute to fatigue cracking in many details.
19.	Lundgren, Karin, 1968, et al. (författare) Tests on anchorage of naturally corroded reinforcement in concrete 2015 Ingår i: Materials and Structures. - : Kluwer Academic Publishers. - 1359-5997 .- 1871-6873. ; 48:7, s. 2009-2022 Tidskriftsartikel (refereegranskat)abstract Many studies on the structural effects of corrosion in reinforcement have been conducted. However, most of them are based on artificially corroded test specimens. Thus, the knowledge available entails one major uncertainty, i.e. whether the results are reliable enough to be used for naturally corroded structures. The purpose of this study was to develop a test method and carry out experiments on naturally corroded specimens taken from an existing structure to investigate the anchorage capacity. Beam specimens were taken from the edge beams of a bridge at repair. The specimens showed corrosion-induced damage to a varying extent from no sign of corrosion to extensive cracking and spalling of the concrete cover. A four-point bending test indirectly supported by suspension hangers was chosen. The beams were strengthened with transverse reinforcement around the suspension hangers to avoid premature failure. Eight successful tests were carried out; in all these tests, diagonal shear cracks preceded a splitting induced pull-out failure; i.e. anchorage failure was achieved as intended. The results showed around 10 % lower capacity for the corroded specimens than for the reference ones. The average bond stress in the anchorage zone was estimated based on the applied load and available anchorage length. The stress was about 16 % lower in the beams with corrosion cracks, and 9 % lower in the beams with cover spalling compared to the reference specimens; there was also a larger variation among the damaged specimens than for the reference specimens. The results extend our knowledge concerning the structural behaviour of corroded reinforced concrete structures during field conditions.
20.	Nilsson, Ulf, et al. (författare) Blommenbergsviadukten, 2-2033-1. Kompletterande bärighetsutredning med avseende på kontroll av kapacitet i gjutfogar baserat på beräkningsmodell utvecklad av Chalmers tekniska högskola 2014 Rapport (övrigt vetenskapligt/konstnärligt)
21.	Ek, Kristine, 1975, et al. (författare) Multi-criteria decision analysis methods to support sustainable infrastructure construction 2019 Ingår i: IABSE Symposium, Guimaraes 2019: Towards a Resilient Built Environment Risk and Asset Management - Report. ; , s. 1084-1091 Konferensbidrag (refereegranskat)abstract The construction of infrastructure projects represents a large sustainability impact, both positive and negative. Increased positive and reduced negative impacts can be achieved through better design and planning of the construction. To make more sustainable choices, well‐defined predictive sustainability assessment methods are required. Multi‐criteria decision analysis (MCDA) is a well-suited method for predictive sustainability assessment. This paper evaluates two MCDA methods for sustainability assessment of infrastructure construction and exemplifies their application with two case studies. The aim of this paper is to discuss if the methods are suitable for identifying the most sustainable alternative during the procurement process of an infrastructure project. It is recommended that MCDA methods are further developed to comply with the recently published EN standard on sustainability assessment of civil engineering works.
22.	Mathern, Alexandre, 1986, et al. (författare) Sustainability-driven structural design using artificial intelligence 2019 Ingår i: 20th Congress of IABSE, New York City 2019: The Evolving Metropolis - Report. ; , s. 1058-1065 Konferensbidrag (refereegranskat)abstract The construction industry is responsible for a large share of the global environmental impact. The need for addressing sustainability and increased competition calls for the development of innovative design methods that include sustainability in a transparent way. The aim of this work is to propose a framework to use machine learning and artificial intelligence (AI) for structural design optimization based on sustainability and buildability criteria. AI opens up new possibilities to optimize and assess structures early in the planning and design stages. In that way, it is possible to decrease the negative and enhance the positive environmental, economic and social impacts and create a more time‐ and cost‐effective design process. The work is meant to serve as a first step toward the development of AI‐based methods in the construction industry, which can bring digitalization in the construction industry to a new level and create new services and business models.
23.	Rempling, Rasmus, 1976, et al. (författare) Automatic structural design by a set-based parametric design method 2019 Ingår i: Automation in Construction. - : Elsevier BV. - 0926-5805. ; 108:December Tidskriftsartikel (refereegranskat)abstract Modern structural design faces new challenges, such as addressing the needs of several stakeholders and satisfying the criteria for achieving sustainability. The traditional design process does not allow resolution of these challenges. The purpose of this project was to investigate the applicability of a Set-Based Parametric Design method to the structural design process of bridges. The focus was on the early design stage, in which the design team evaluates design alternatives against a chosen set of criteria. The main challenge in this stage of design is that the process should be cost- and time-effective while allowing comparison of the different alternatives and their evaluation in terms of the different design criteria. Certainly, structural design is often performed by a discussion between the different stakeholders involved in this process, i.e. the client, contractor, and engineering team. An evaluation of alternatives against criteria requires a more detailed design, which is contradictory to the early design stage when information is scarce. The selected approach was to develop a script that can generate information for decision-making, automate the structural design process, perform common routine design tasks, and control the numerical analysis. The method combined Set-Based Design, Parametric Design, Finite Element Analysis and Multi-Criteria Decision Analysis. Three existing bridges were selected to demonstrate the applicability of the developed method. The method was successfully applied and it was observed that it resulted in bridges that were more efficient in terms of material costs and carbon dioxide equivalent emissions compared with existing bridges. By delaying the decisions and developing the sets of alternatives, various alternatives can be assessed and evaluated, in the design stage, against different sustainability criteria.
24.	Almusaed, Amjad, 1967-, et al. (författare) Introductory Chapter : Overview of Sustainable Cities, Theory and Practices 2019 Ingår i: Sustainable Cities. - Kroatia : INTECH. - 9781789855234 - 9781839620560 - 9781789855241 ; , s. 2-22 Bokkapitel (refereegranskat)
25.	Bannova, Olga, 1964 (författare) Architectural approach to planning in the extreme arctic environment. 2016 Ingår i: archiDOCT: Transformable Architecture. - 2309-0103. ; 4:1, s. 53-67 Tidskriftsartikel (refereegranskat)abstract Extreme environments in Polar Regions share similar facilities and operations, design and planning challenges: extreme cold temperatures, structural problems, high standards for materials, resources limitations (including people), transportation and logistics. Nevertheless, they differ depending on local cultural and social traditions and climate challenges specific to a particular region. Environmental hardships create challenges that reflect on sets of architectural requirements. The paper discusses these challenges and their influences on form developing factors, site orientation and circulation, - factors that affect budget considerations as well. The paper also discusses criticality of addressing such impacts at the programming design stage especially in challenging environments, in order to avoid costly adjustments at later development stages.The paper argues that integrating an architectural approach into planning of construction and related to it activities in Polar Regions is critical for enabling sustainability and resilient strategies there. The importance of such integration comes from the fact that engineering-oriented developers follow strictly industry-specific technical regulations and standards. Simultaneously, planning construction work and design in extreme conditions becomes a more complex process that calls for a new methodology, which would differ from common regulatory “checklists” that most companies implement in their practices there.This paper outlines and categorizes recurrent and specific to extreme environment and conditions events based on select research methods that include verbal data collection and case studies analysis. Figures Of Merit method employed for identification of important lessons that can be applied across different settings; and the ‘HSB Sustainable Living Lab’ project is suggested for effectiveness and verification purposes.Understanding of relationships and influences between different facets of human society and architecture can help to find a design approach and optimize needs and requirements for various types of people living and working in extreme environments of Polar Regions, their societies and cultures.
26.	Rempling, Rasmus, 1976, et al. (författare) Aspects of Integrated Design of Structures: Parametric Models, Creative Space and Linked Knowledge 2015 Ingår i: Civil Engineering and Architecture. - 2332-1121. ; 3, s. 143-152 Tidskriftsartikel (refereegranskat)abstract In the construction industry, collaborative working methods with overlapping domains have been developing side by side with information and communication technology. Recently, efforts have been made to combine these methods in order to facilitate the integration of disciplines. Research on collaborative work has resulted in the promising "integrated project delivery" methodology, whereas research on information and communication technology has resulted in building information modelling. In this paper, we propose three principles for integrated design: "parametric models", "creative space" and "linked knowledge". These principles have been derived during the course of the TailorCrete Project. The project involves contributions from architects, structural engineers, contractors and building material manufacturers, as well as scientists of the built environment. All principles are elaborated upon with regard to their connection to integrated design and how they are carried out in practice; the elaboration is based on results collected from the TailorCrete project and from research results found in the literature. This paper concludes that parametric models, creative space and linked knowledge are the three main aspects that should be pursued in order to achieve and implement a practical integrated design process
27.	Adam, Abderisak, 1988, et al. (författare) Take a Chance on Me? Construction Clients' Perspectives on Risk Management 2015 Ingår i: Procedia Economics and Finance. - 2212-5671. ; 21, s. 548-554 Konferensbidrag (refereegranskat)abstract Having been overwhelmed with a strikingly large list of things that can go wrong, public clients have consistently found themselves subjected to many risks associated with construction projects. As the scale of projects increases, the severity of risks intensifies. This study sets out to highlight a particular set of risks associated with strategic decision making in public construction projects. Of particular importance stands the client organizations’ capacity to properly manage risks rooted in poor decision making that leads to many types of project failure. To curb the negative effects of poor decision making, varying organisational configurations have been adopted by clients. This paper investigates the six Swedish public client organizations’ risk management procedures, the risk types and the frequency by which they reference risk management in their internal documents. The purpose is to explore how organisational measures influence a client's ability to undertake major construction projects in a manner that is conducive to effective project delivery. The present study is part of an ongoing research project concerning the capabilities of public clients in managing large scale construction projects.
28.	Blomfors, Mattias, 1990, et al. (författare) Evaluation of safety formats for non-linear finite element analyses of statically indeterminate concrete structures subjected to different load paths 2016 Ingår i: Structural Concrete. - : Wiley. - 1751-7648 .- 1464-4177. ; 17:1, s. 44-51 Tidskriftsartikel (refereegranskat)abstract To increase the efficiency of new structures and perform safety evaluations of existing structures, it is necessary to model and analyse the non-linear behaviour of reinforced concrete. The applicability of the safety formats in present design codes is unclear for indeterminate structures subjected to loading in several directions. The safety formats in fib Model Code 2010 have been evaluated for a reinforced concrete frame subjected to vertical and horizontal loading and the influence of load history studied. Basic reliability methods were used together with response surfaces to assess the failure probabilities and one safety format did not meet the intended safety level. The results indicate the importance of load history and it is concluded that more research is required regarding how load history influences the safety level of complex structures.
29.	Blomfors, Mattias, 1990, et al. (författare) Partial safety factors for the anchorage capacity of corroded reinforcement bars in concrete 2019 Ingår i: Engineering structures. - : Elsevier BV. - 0141-0296 .- 1873-7323. ; 181, s. 579-588 Tidskriftsartikel (refereegranskat)abstract Many reinforced concrete bridges in Europe and around the world are damaged by reinforcement corrosion and the annual maintenance costs are enormous. It is therefore important to develop reliable methods to assess the structural capacity of corroded reinforced concrete structures and avoid unnecessary maintenance costs. Although there are advanced models for determining the load carrying capacity of structures, it is not obvious how they should be used to verify the performance of existing structures. To confidently assess the bond of corroded reinforcement in concrete, for example, the calculation model must give a sufficient safety margin. When designing new structures, semi-probabilistic approaches (such as the partial safety factor method) are adopted to achieve the target reliabilities specified in structural design codes. This paper uses probabilistic methods to develop partial factors for application in an existing bond model, to assess the safety of corroded reinforced concrete structures. The response of the bond model was studied using Monte Carlo (MC) simulations for several design cases, with probability distributions fitted to the results. Partial factors were then derived, based on these distributions. Furthermore, an MC-based simulation technique called “importance sampling” was used to study the reliability of several deterministic bond assessments conducted using these partial factors. The results show that deterministic assessments which use the proposed partial factors lead to a safety level at least equal to the target value. The results presented in this paper will support the assessment of reinforced concrete structures with anchorage problems and give a reasonable approximation of the anchorage capacity with sufficient safety margin. When generalised to cover other failure modes and structural configurations, this will enable better utilisation of damaged structures and lead to major environmental and economical savings for society.
30.	Coronelli, Dario, et al. (författare) FIB model code 2020 - Structural models for existing concrete structures 2018 Ingår i: FIB 2018 - Proceedings for the 2018 fib Congress: Better, Smarter, Stronger. - 2617-4820. ; , s. 3019-3040 Konferensbidrag (refereegranskat)abstract The paper gives an overview of this ambitious project, which builds upon the achievements of fib MC2010, the previous edition of the fib Model Code. MC2020 will deal with both the design of new structures and all the activities associated with the through-life management and care of existing concrete structures, including matters such as inservice assessment and interventions to extend the life / improve the performance of these structures. Particular attention will be paid to issues specific to existing structures. Relevant structural models are planned for the determination of their load capacity / structural reliability, serviceability, remaining service life etc taking account of: • Load-carrying behaviour not considered in design, such as compressive membrane action and the increase in concrete compressive strength with time due to ongoing hydration effects. • Load-carrying behaviour in deteriorated members and structures, which is different to those members which have not experienced deterioration. The paper gives consideration to corrosion of reinforced concrete members and prestressed concrete members, as well as to the effects of other forms of deterioration such as alkali-aggregate reactions and frost damage. The paper also notes some of the differences between the approaches employed for Life Cycle Assessment and Design (LCA / LCD) based on deterioration models, and the assessment of the present condition of the structure (i.e. at a given moment in time) which utilise mechanical models to represent the influences of the deterioration processes which are active.
31.	Fernandez, Ignasi, 1984, et al. (författare) Structural effects of steel reinforcement corrosion on statically indeterminate reinforced concrete members 2016 Ingår i: Materials and Structures/Materiaux et Constructions. - : Springer Science and Business Media LLC. - 1359-5997. ; 49, s. 4959-4973 Tidskriftsartikel (refereegranskat)abstract Steel corrosion in reinforced concrete structures produces loss of reinforcement area and damage in the surrounding concrete. As a consequence, increases in deflections, crack widths and stresses may take place, as well as a reduction of the bearing capacity, which depends on the structural scheme and redundancy. In this paper an experimental study of twelve statically indeterminate beams subjected to different levels of forced reinforcement corrosion is presented. Different sustained loads were applied during the corrosion phase to assess their influence on the effects of corrosion. An important increase in deflections was registered in all corroded beams, especially in those subject to higher load levels. It was also found that the rate of corrosion was affected by the load level. Internal forces redistributions due to induced damage were measured. Finally, the experimental results were compared with those predicted by a non-linear time-dependent segmental analysis model developed by the authors, obtaining in general good agreement. © 2016, RILEM.
32.	Gil Berrocal, Carlos, 1986, et al. (författare) Analytisk beräkningsmodell för tvångsprickor hos kombinationsarmerade konstruktionselement 2018 Ingår i: Bygg och teknik. - 0281-658X. ; 2018:7, s. 30-33 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract Kombinationsarmering kan vara en effektiv lösning för att begränsa sprickbildning orsakad av tvångskrafter och samtidig minska arbetsinsatsen som armeringen medför. Befintliga modeller som beaktar sprickor orsakade av tvångkrafter saknas dock för kombinationsarmerade betongelement. I ett nyligen avslutat SBUF-projekt som har genomförts på Thomas Concrete Group i samarbete med Chalmers tekniska högskola har en befintlig analytisk beräkningsmodell för tvångsprickor vidareutvecklats och beräkningar har jämförts med resultat från experiment. I den här artikeln beskrivas modellen och dess förmåga att prediktera antalet sprickor och sprickbredd i betongelement utsatta för förhindrad krympningsdeformation.
33.	Lanau, Maud, 1989, et al. (författare) The Industrial Ecology of the Göteborg City Region — a first appraisal 2015 Ingår i: International Society for Industrial Ecology 2015. Konferensbidrag (refereegranskat)abstract An infrastructure system – here, the industrial ecology of Gothenburg — is more important for society than we usually credit it for (cf. Technology is society made durable, Latour 1990) and is taken for granted by most inhabitants. Gothenburg is an unusually well-developed and interconnected infrastructure system. The first district heating facility was put in operation in 1952. Soon enough, waste was re-used and recycled into energy, into both electricity and heat. With time, more varied materials and sources became integrated into the system to also produce biogas and compost. The project makes a historiographic description of how the industrial ecology of the Gothenburg city region developed since the Gothenburg technical environmental flow system is unique in size, age, diversity of flows and functions. The study describes environmental flows and their actors in a networked organization. The focus on interconnectivity of the different actors, flows and sectors of Gothenburg requires the combination of several theoretical fields. Such theoretical fields include Networked Learning, which takes a relational stance in which learning takes place both in relation to others, and in relation to learning resources (Dirckinck-Homfeld et al., 2009); STS (Science Technology and Society), which study how technical innovation are affected by social, political and cultural values, and how these innovation affect, in turn, political, social and cultural values; (Joerges & Novotny, 2003); and Urban Metabolism, which uses models to facilitate the description and analysis of the flows of the energy and materials within cities, such as Material Flow Analysis of a city, and provides a metaphorical framework to study the interactions of natural and human systems in specific regions. Preliminary findings will be presented.
34.	Mangold, Mikael, 1982 (författare) The effect of resource sustainability interventions on social sustainable development in the built environment 2013 Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract There are several sustainable development targets for the Swedish housing market. The sector as a whole is expected to contribute to the reduction of greenhouse gases. Housing prices should increase and not inflate. Meanwhile, the development of the built environment should contribute to well being and decrease segregation. Prioritization amongst these targets is often done through policy and by actors in the housing market. This thesis focuses on the trade-offs between environmental and social sustainable development targets. The thesis builds on two studies of development in the built environment. The main study describes an environmental upgrade of housing in a disadvantaged area of Gothenburg, and the second investigates a redevelopment area with high environmental ambitions. Environmental targets, such as CO2 reduction, have in some cases been profitably achieved in housing projects in Sweden. The principal study of this thesis describes the implementation of volumetric billing of water at Bredfjällsgatan which successfully reduced water usage and was profitable for the implementing real estate company. However, the system’s change also increased the average monthly costs for the households, and the average monthly costs increased even more in households where the inhabitants were unemployed. The lock-in effect of welfare dependency is increased by rising monthly expenses. This group lacks economic incentive to save water since welfare pays for water usage. The analyses of water consumption data show that while economic incentives account for some reduction of water consumption, other parameters such as household size, crowdedness of apartments, and household level of education are also important factors. Households receiving welfare are not economically affected by the implementation of volumetric billing of water but are further socially excluded from society when trapped in welfare dependence. The real estate owner states economic and environmental aspects as motivators for the system’s change. Social sustainable development targets on a societal level are not an outspoken priority to the same extent. The real estate owners in disadvantaged housing areas should be recognized as important actors in the development to tackle segregation of the housing market.The second study presents empirical insights from a housing area that is being built with high environmental ambitions. Perspectives of sustainable development amongst developers in the area differ, but it is apparent that social dimensions of sustainable development receive less attention. The complexity of social dimensions is not fully addressed. Social sustainable development is for example thought of as comfortable outdoor environments in the area, while the larger societal impacts of the housing project were not considered to the same extent. Integration, affordability, and equity were given direct focus; instead these targets are often assumed to be reached by varying apartment sizes and mixing tenure in the area.
35.	Nanukuttan, S. V., et al. (författare) Taking performance to practice – simplified in situ approach for specifying concrete for chloride environments 2016 Ingår i: fib Symposium. - 2617-4820. ; , s. 1-10 Konferensbidrag (refereegranskat)abstract The application of conservative structural codes such as EN1992 with high factors of safety and performance based compliance measures for concrete strength means that actual structural loading rarely exceeds the capacity and therefore has negligible influence on long term load carrying capacity. Majority of structures fail due to physical and chemical changes that concrete undergoes influenced by the exposure environment and subsequent reinforcement corrosion and loss of load carrying capacity. Lack of appreciation of concrete and its interactions with exposure environments, makes Designers and Engineers adhere more closely to prescriptive standards developed for relatively less aggressive environments. The data from exposure sites and real structures prove categorically that the prescriptive specifications are in adequate, especially for chloride environments. A performance-based approach similar to that followed for strength guarantee is proposed as a way forward for bringing durability into the forefront. For marine and de-icing salt environments, a handful of measurable parameters control the flow of chloride ions into concrete and such parameters form the core of most transport models. This article shows the scope of a simplified approach to chloride transport modelling using these core parameters for one chloride exposure environment. Further, the authors put forward a strong case for in situ measurements and the benefits it can have on assessing the whole structure. Examples for predicting the remaining service life as well as forming performance-based specification are also provided.
36.	Othman, Sarbaz Najib, 1971, et al. (författare) Are driving and overtaking on right curves more dangerous than on left curves? 2010 Ingår i: Annals of advances in automotive medicine. - : Association for the Advancement of Automotive Medicine. - 1943-2461. ; 54, s. 253-264, s. 253-264 Tidskriftsartikel (refereegranskat)abstract It is well known that crashes on horizontal curves are a cause for concern in all countries due to the frequency and severity of crashes at curves compared to road tangents. A recent study of crashes in western Sweden reported a higher rate of crashes in right curves than left curves. To further understand this result, this paper reports the results of novel analyses of the responses of vehicles and drivers during negotiating and overtaking maneuvers on curves for right hand traffic. The overall objectives of the study were to find road parameters for curves that affect vehicle dynamic responses, to analyze these responses during overtaking maneuvers on curves, and to link the results with driver behavior for different curve directions. The studied road features were speed, super-elevation, radius and friction including their interactions, while the analyzed vehicle dynamic factors were lateral acceleration and yaw angular velocity. A simulation program, PC-Crash, has been used to simulate road parameters and vehicle response interaction in curves. Overtaking maneuvers have been simulated for all road feature combinations in a total of 108 runs. Analysis of variances (ANOVA) was performed, using two sided randomized block design, to find differences in vehicle responses for the curve parameters. To study driver response, a field test using an instrumented vehicle and 32 participants was reviewed as it contained longitudinal speed and acceleration data for analysis. The simulation results showed that road features affect overtaking performance in right and left curves differently. Overtaking on right curves was sensitive to radius and the interaction of radius with road condition; while overtaking on left curves was more sensitive to super-elevation. Comparisons of lateral acceleration and yaw angular velocity during these maneuvers showed different vehicle response configurations depending on curve direction and maneuver path. The field test experiments also showed that drivers behave differently depending on the curve direction where both speed and acceleration were higher on right than left curves. The implication of this study is that curve direction should be taken into consideration to a greater extent when designing and redesigning curves. It appears that the driver and the vehicle are influenced by different infrastructure factors depending on the curve direction. In addition, the results suggest that the vehicle dynamics response alone cannot explain the higher crash risk in right curves. Further studies of the links between driver, vehicle, and highway characteristics are needed, such as naturalistic driving studies, to identify the key safety indicators for highway safety.
37.	Plos, Mario, 1963, et al. (författare) Recommendations for Finite Element Analysis for Design of RC Slabs 2014 Ingår i: Nordic Concrete Research. - 0800-6377. - 9788282080439 ; 2014:2, s. 39-42 Konferensbidrag (refereegranskat)abstract The finite element method (FEM) is increasingly used for design of reinforced concrete structures. 3D FE analysis can provide more accurate structural analysis, but to use its full strength in daily design a number of critical issues have been addressed. Practical guidelines are provided for detailed design of reinforced concrete slabs. Recommendations are given on linear FE modelling, e.g. regarding geometry, support conditions and mesh density, as well as on the use of analysis results, e.g. regarding stress concentrations, choice of critical sections and redistribution widths for practical reinforcement design.
38.	Sciegaj, Adam, 1990 (författare) Multiscale Modelling of Reinforced Concrete 2018 Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract Since concrete cracks at relatively low tensile stresses, the durability of reinforced concrete structures is highly influenced by its brittle nature. Cracks open up for ingress of harmful substances, e.g. chlorides, which in turn cause corrosion of the reinforcement. Crack widths are thus limited in the design codes, and accurate prediction methods are needed. For structures of more complex shapes, current computational methods for crack width predictions lack precision. Hence, the development of new simulation tools is of interest. In order to properly describe the crack growth in detail, cracking of concrete, constitutive behaviour of steel, and the bond between them must be accounted for. These physical phenomena take place at length scales smaller than the dimensions of large reinforced concrete structures. Thus, multiscale modelling methods can be employed to reinforced concrete. This thesis concerns multiscale modelling of reinforced concrete. More specifically, a two-scale model, based on Variationally Consistent Homogenisation (VCH), is developed. At the large-scale, homogenised (effective) reinforced concrete is considered, whereas the underlying subscale comprises plain concrete, resolved reinforcement bars, and the bond between the two. Each point at the large-scale is associated with a Representative Volume Element (RVE) defining the effective response through a pertinent boundary value problem. In a numerical framework, the procedure pertains to a so-called FE 2 (Finite Element squared) algorithm, where each integration point in the discretised large-scale problem inherits its response from an underlying RVE problem. In order to properly account for the concrete–reinforcement bond action, the large-scale problem is formulated in terms of a novel effective reinforcement slip variable in addition to homogenised displacements. In a series of FE 2 analyses of a plane problem pertaining to a reinforced concrete deep beam with distributed reinforcement layout, the influence of boundary conditions on the RVE, as well as the sizes of the RVE and the large-scale mesh, are studied. The results of the two-scale analyses with and without incorporation of the effective reinforcement slip are compared to fully-resolved (single-scale) analysis. A good agreement with the single-scale results in terms of structural behaviour, in particular load-deflection relation and average strain, is observed. Depending on the sub-scale boundary conditions, approximate upper and lower bounds on structural stiffness are obtained. The effective strain field gains a localised character upon incorporation of the effective reinforcement slip in the model, and the predictions of crack widths are improved. The two-scale model can thus describe the structural behaviour well, and shows potential in saving computational time in comparison to single-scale analyses.
39.	Shu, Jiangpeng, 1987, et al. (författare) Assessment of a cantilever bridge deck slab using multi-level assessment strategy and decision support framework 2019 Ingår i: Engineering structures. - : Elsevier Ltd. - 0141-0296 .- 1873-7323. ; 200 Tidskriftsartikel (refereegranskat)abstract A Multi-Level Assessment Strategy has previously been proposed and proved feasible for structural analysis of existing RC slabs. In this paper, the Multi-Level Assessment Strategy, which focuses on sophisticated structural analysis, was used to investigate the load-carrying capacity and structural behaviour of a composite bridge with an RC bridge deck slab subjected to a concentrated load. In addition to more sophisticated structural analysis, improved knowledge content about the structure and more advanced models for uncertainty consideration were also incorporated in a systematic way for higher levels of assessment. Furthermore, a decision support system was adopted, in which the cost for different alternatives regarding if and how the assessment should be enhanced with respect to model sophistication, knowledge content and modelling uncertainty were compared in a systematic way. The results show not only that the load-carrying capacity and the structural behaviour can be assessed with different level of detailing, but also that the cost for each level of assessment can be evaluated with a decision support system, facilitating more sustainable management of infrastructure.
40.	Tegos, Ioannis, et al. (författare) Experimental and analytical research on the influence of the shear span ratio on the maximum shear strength of hollow circular R/C cross sections 2013 Ingår i: fib Symposium TEL-AVIV 2013: Engineering a Concrete Future: Technology, Modeling and Construction, Proceedings. - 9789659203901 ; , s. 369-372 Konferensbidrag (refereegranskat)abstract This paper investigates a particular problem encountered in the design of reinforced concrete elements of circular hollow cross sections. Such problems still appear to be unclear, due to the fact that the current codes deal, al most exclusively, with the design of rectangular cross sections and no specific provisions are given for other cross sections. Hence, the design of such members is being dealt with either poor methods or with the use of methods that normally apply to rectangular cross sections. Specifically, the research deals with the influence of the shear span ratio on the maximum shear strength of reinforced concrete members with circular hollow cross sections. Six reinforced concrete specimens having a circular hollow cross section have been tested. lt was attempted to verify the accuracy of the proposed analytica(model, which estimates the shear strength for circular hollow R/C cross sections. The study was mainly focused on the shear span ratio, which is the dominant factor in the design of structural elements under shear loading. It is useful to be noted that R/C elements of thin hollow circular cross section are used in the case of bridge piers.
41.	Berrocal, Carlos Gil, 1986, et al. (författare) The effect of fibres on steel bar corrosion and flexural behaviour of corroded RC beams 2018 Ingår i: Engineering Structures. - : Elsevier BV. - 1873-7323 .- 0141-0296. ; 163, s. 409-425 Tidskriftsartikel (refereegranskat)abstract This paper reports the results of an experimental programme aimed at investigating the influence of fibre reinforcement on the corrosion process of conventional steel rebar embedded in cracked concrete and on the flexural behaviour of reinforced concrete beams. Un- and pre-cracked reinforced concrete beams were subjected to natural corrosion through cyclic exposure to a 10% chloride solution for a period of three years. Subsequently, flexural tests were carried out under three-point bending configuration. Gravimetric measurements showed higher corrosion levels for bars in plain concrete compared to fibre reinforced concrete, and visual inspection of the bars revealed that fibres promoted a more distributed corrosion pattern. From detailed examination of the bars through 3D laser scanning technique, the main parameter controlling the local corrosion level of individual pits appears to be the local interfacial conditions; grater loads during pre-cracking and repeated load cycles yielded greater cross-sectional losses. Moreover, there was a tendency for more localized corrosion in beams with open cracks, indicating a possible impact of crack width on the extension of corrosion. The results from the flexural tests showed a consistent increase of load capacity for fibre reinforced beams compared to their plain concrete counterparts but only a marginal influence of the fibres on the rotation capacity. Furthermore, the rotation capacity of the beams was found to decrease several times faster than the load capacity with increasing loss of rebar cross-sectional area.
42.	Ekström, Daniel P T, 1976 (författare) Integrated structural and construction engineering – A study of project team performance in Swedish bridge design 2019 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract The Swedish Transport Administration (STA) ambitiously strives to increase the level of productivity and innovation within its operations while meeting and surpassing national sustainability objectives. In this effort, the STA has concluded that climate gas emissions from construction, operation, and maintenance of the infrastructure must be reduced for Sweden to maintain its position as a pioneer and to reach both national and global climate goals. Emissions from road, rail, and other civil works is mainly related to the production of construction materials, such as construction steel, concrete and reinforcement in bridges, retaining walls, and other structures. For bridges, normally designed for a long service-life, the environmental impact of all stages after realization is greatly dependent on and constrained by decisions made during design and construction of the structure. To succeed in realizing effectiveness in bridge construction project is only possible by close cooperation between all project participants, i.e. client, consultant(s), and contractor(s). The construction industry is often described as complex, multidisciplinary, and project-focused but with no clear boundaries of who actually owns processes and, consequently, the development of them. The overall purpose of this research is, therefore, to contribute to framing a systematic and holistic design approach fostering many kinds of project-settings and pre-requisites. This research aims to further understand how to introduce construction knowledge in the early design stages through utilizing an approach with integrated projects teams. The thesis is based on several studies exploring how integration is related to the bridge construction process and the key features are for such integration. Further, this thesis explores the prevailing interprofessional dialogue in the Swedish bridge construction process and how this may both support and hinder knowledge and experience transfer in the interprofessional interface. Given the complexity in construction today, all participants involved, individually, will lack some pieces of the puzzle, but that collectively, they can gather their knowledge and resources to achieve success for all parties involved. When integration is seen from this perspective, the following key features crystallize; skills to collaborate and communicate; interdependency between the parties; importance for the structural engineer to receive feedback from, and to have a dialogue with, the contractors; teams to be provided with the right people. The contribution of this thesis is that it provides further knowledge to develop and improve the contemporary approach in the design and construction of bridges.
43.	Gil Berrocal, Carlos, 1986, et al. (författare) The road to sensor-driven cloud-based infrastructure management 2018 Ingår i: SynerCrete'18: Interdisciplinary Approaches for Cement-based Materials and Structural Concrete: Synergizing Expertise and Bridging Scales of Space and Time.. ; , s. 823-828 Konferensbidrag (refereegranskat)abstract Today, the accelerated degradation of many concrete structures poses a major challenge for the proper maintenance of the transport infrastructure. Therefore, inspection and maintenance operations constitute an important part of the recurrent costs of infrastructure. Furthermore, the increasing migration of population to urban areas has made sustainable development an imperative need. This need has become a driving force for innovation and new challenges such as the concept of smart cities and infrastructure. The successful utilization of newly available technologies will enable a whole new range of possibilities such as sensor driven cloud-based strategies for infrastructure management, which will promote an upgrade of the current infrastructure network to a new generation of safer, more efficient and more sustainable smart infrastructure: the infrastructure 2.0. The aim of this paper is to review the state-of-the-art of the different key technologies comprising a smart monitoring system, focusing on the aspects that are required to ensure a successful implementation of such system. The main result of the study is a scientific roadmap that can serve as a guide for traffic administrations and academic institutions in their task to develop and create a new infrastructure management strategy based on emerging technologies and innovative processes.
44.	Haghighatafshar, Salar, et al. (författare) Hydroeconomic optimization of mesoscale blue-green stormwater systems at the city level 2019 Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694. ; 578 Tidskriftsartikel (refereegranskat)abstract The development of tools to help cities and water utility authorities communicate and plan for long-term sustainable solutions is of utmost importance in the era of a changing and uncertain climate. This study introduces a hybrid modeling concept for the cosimulation of mesoscale blue-green stormwater systems and conventional urban sewer networks. The hybrid model successfully introduces the retention/detention effects of mesoscale blue-green stormwater systems to the hydraulic dynamics of the sewer network. The cosimulation package was further facilitated with a cost-oriented multiobjective optimization algorithm. The aim of the scalar multiobjective optimization was to minimize the total cost comprising both flooding costs and action costs – both parameters solely representing the financial components of cost – through optimal placement of mesoscale blue-green systems of optimal size. The suggested methodology provides a useful platform for sustainable management of the existing sewer networks in cities from a hydroeconomic perspective.
45.	Hallbjörn, Lars (författare) Betongplattor, beräkning och dimensionering vid koncentrerade upplagsreaktioner och fria kanter 2019 Rapport (övrigt vetenskapligt/konstnärligt)abstract Dimensionering av armerade betongplattor utförs i allmänhet enligt elasticitetsteori varvid finit elementmetod (FEM) mestadels tillämpas for snittkraftsberäkningen. För tolkning av beräkningsresultat och for att välja lämpliga kompletteringar har i denna utredning behandlats · moment i och kring singulära punkter (vid koncentrerade upplagsreaktioner samt vid fritt inre hörn), · tvärkrafter kring koncentrerade upplagsreaktioner m a p genomstansning, och · tvärkrafter längs fria kanter och i fritt inre hörn. Exemplen belyser hur beräkningsresultaten påverkas vid variation av olika parametrar och tolkningen ger vägledning for praktiskt konstruktionsarbete. Plattor med pelarupplag, avslutat linjeupplag, olika typer av inåtgående hörn samt med fri kant har analyserats för jämnt fördelad belastning. Fasta, inspända, elastiska och fjädrande upplag har tillämpats. Inverkan av varierande stödväggshöjder och plattjocklekar har studerats. Mindlinelement 1,0x1,0, 0,5x0,5, 0,25x0,25 och 0,125x0,125 m har använts samt i några fall även kirchoffelement. Böjmoment i och kring singulara punkter kan vid dimensioneringen utjämnas till medelvärden inom en medverkande bredd. Exemplen med varierande elementstorlek visar att medelmomentet blir måttligt beroende av elementstorleken. Vid fritt inre hörn inverkar inte elementstorleken. I vissa fall bör införas elastiska stod exempelvis i form av stödjande väggar. Olika vägghöjder har provats. Att införa fjäderförsedda upplagslinjer istället för väggar ar inte rättvisande. Det bör vara en acceptabel bedömning att element med en bredd lika med plattjockleken väl avspeglar plattans funktion kring singulara punkter. For pelarstöd och lageruppläggning kan hänsyn till stödytans storlek tas genom manuell justering av momenten i och kring den singulara punkten. Enkla formler for medelmoment och toppmoment ges. Tvärkrafter kring koncentrerade upplagsreaktioner studeras m a p genomstansning. Metod att beräkna bärförmågan m h t stansning framgår av normer. Här behandlas följande tillhörande frågor: · stödreaktion jämte excentricitet vid de olika plattgeometrierna, · tilläggsfaktor för variation hos huvudtvärkraften runt stödet, samt · inverkan av elastiska stöd. Olika elementstorlekar ger i de studerade plattorna praktiskt taget lika stodreaktioner. Mindlinelement bör tillämpas. Elastiska stod jämnar ut reaktioner. Huvudtvärkrafterna i en krets runt stödande resp. inåtgående hörn reduceras då betydligt. En beräkning av rätvinklig och snedvinklig broplatta visar att tvärkrafterna kan fördelas ickerotationssymmetriskt även vid centriskt belastade (ledade) pelarstöd. Inåtgående fritt hörn är en singular punkt. Stansningsberäkning inte aktuell. Den utförda tolkningen av plattmodellens tvärkraft stöds av en balkrostmodell. Ett skadefall beskrivs där omfattande skjuvsprickbildning tolkas såsom orsakat av att hänsyn inte tagits till tvärkraftsvariationen kring pelarstöd. Tvärkraften längs en fri kant utgörs av ett ”basvärde” plus ett kanttillskott där tillskottet är lika med vridmomentet strax innanför kanten. Tillskottet blir ungefär lika vid de olika elementstorlekarna. De olika beräkningsresultaten vid mindlin- resp. kirchoffelement påvisas och anvisningar for tolkning ges. I bilagor · ges armeringsanvisningar, · härleds analytiskt momenttopp i cirkulär platta, samt · visas resultat av jämförande balkrostberäkningar.
46.	Karlsson, Mats, 1974, et al. (författare) Consequences of sample disturbance when predicting long-term settlements in soft clay 2016 Ingår i: Canadian Geotechnical Journal. - : Canadian Science Publishing. - 1208-6010 .- 0008-3674. ; 53:12, s. 1965-1977 Tidskriftsartikel (refereegranskat)abstract An approach for assessing the effects of sample quality is presented. Soil samples were taken using a 50 mm Swedish STII piston sampler and the Norwegian University of Science and Technology (NTNU) mini-block sampler from a soft clay test site. Differences in laboratory test results are identified for several stress paths, assisted by simulations made using an advanced constitutive model. Hitherto such comparisons have focused on differences in basic engineering properties such as strength and stiffness. The effect of choosing alternative model parameters from piston and block samples is demonstrated through the analysis of the long-term settlement of an embankment. The simulations show that substantially larger settlements and lateral displacements are predicted using parameters obtained from the piston samples. Furthermore, the magnitude of the differences is larger than expected. This demonstrates that for this application, relatively small differences in the assessed sample quality, using traditional laboratory data interpretation methods, are amplified when applied to a prototype boundary value problem. It is suggested that a little more care in sampling and testing can result in large cost savings as a result of the more reliable model parameters that can be extracted, particularly when the improved sampling is combined with the use of an advanced constitutive model.
47.	Lundgren, Karin, 1968, et al. (författare) A model for the anchorage of corroded reinforcement : Validation and application 2015 Ingår i: Concrete - Innovation and Design. - : Technical University of Denmark. ; , s. 135-136, s. 135-136, s. 135-136 Konferensbidrag (refereegranskat)abstract When reinforcement in concrete corrodes, splitting stresses around corroded bars may lead to cover cracking and even cover spalling, affecting the anchorage. The aim of this study was to validate an existing one-dimensional (1D) analysis for anchorage capacity, and to show how it can be applied in assessment of existing bridges. The 1D analysis was validated through comparisons to experiments and detailed 30 finite element analyses. The methodology is exemplified in assessment of two bridges built in the 1960s. The bridges exhibit systematic damage in the form of spalled concrete on the bottom side of the main beams at cast joints where large amounts of reinforcement are spliced. The anchorage length needed to anchor the yield force was calculated from the bond-slip response, using the one-dimensional bond-slip differential equation. The model proved to be easy to use in practical design work. Furthermore, the bridges could be shown to have sufficient capacity, and costly strengthening could be avoided. This work clearly demonstrates the potential to certify sufficient load-carrying capacity of corroded reinforced concrete structures through improved models.
48.	Nilforoush, Rasoul, et al. (författare) Numerical and Experimental Evaluations of Influence of Member Thickness, Anchor Head Size, and Surface Reinforcement on Tensile Breakout Capacity of Anchor bolts 2017 Ingår i: Connections between Steel and Concrete. - Stuttgart. - 9783945773062 ; , s. 752-764 Konferensbidrag (refereegranskat)abstract The influence of member thickness, size of anchor head, and orthogonal surface reinforcement on the tensile breakout capacity of cast-in-place headed anchors in uncracked concrete was studied both numerically and experimentally. The aim of this paper is to form a background for developing improved methods for the design of new fastenings as well as the assessment of current anchorages in practice. For this purpose, anchor bolts at various embedment depths (hef=50–500 mm) were simulated in plain and reinforced concrete members of various thicknesses (H=1.5–5.0∙hef). Three different head sizes of anchor bolts (i.e. small, medium and large) were also considered at each anchor embedment depth. Furthermore, to verify the numerical findings, a series of anchor pullout tests were carried out at which the testing parameters were similar to those in the numerical study.Numerical and experimental results show that the tensile breakout capacity of anchor bolts increases by increasing the member thickness or if surface reinforcement is present. The anchorage capacity further increases with increasing the anchor head size. The anchorage behavior becomes ductile by increasing member thickness or by having surface reinforcement, whereas it becomes stiff and more brittle by increasing the size of anchor head. To account for the influence of member thickness, size of anchor head, and orthogonal surface reinforcement on the tensile breakout capacity of headed anchors, the CC method was modified and extended by incorporating three modification factors.
49.	Nilforoush, Rasoul, et al. (författare) Numerical Modelling and Experimental Verification of Pullout Loading of Anchor Bolts in Reinforced Concrete Structures 2016 Ingår i: IABSE CONGRESS, STOCKHOLM, 2016. - CH - 8093 Zürich, Switzerland. - 9783857481444 ; , s. 2172-2178 Konferensbidrag (refereegranskat)abstract The aim of this study is to provide a numerical model which can realistically present the failure load and failure mechanism of pullout loaded anchor bolts (headed studs) in reinforced concrete structures. The numerical analysis is carried out through a three-dimensional finite element (FE) code based on the Microplane constitutive law. The intension is to calibrate the FE model and to verify the numerical results against available test results. The calibrated FE model is intended to be used for an ongoing study to evaluate the influence of member thickness, surface reinforcement and size of anchor head on the tensile capacity and performance of anchor bolts.The simulation results showed very good agreements with the available test results. The objectivity of numerical modelling in respect to the size of finite elements as well as the defined boundary conditions was confirmed by additional numerical analyses.
50.	Tahershamsi, Mohammad, 1986, et al. (författare) Investigating correlations between crack width, corrosion level and anchorage capacity 2017 Ingår i: Structure and Infrastructure Engineering. - : Taylor & Francis. - 1573-2479 .- 1744-8980. ; 13:10, s. 1294-1307 Tidskriftsartikel (refereegranskat)abstract In assessing existing structures, inspection results need to be linked to the effects on load-carrying capacity; to provide such information, this study has investigated the correlation between splitting crack width, corrosion level and anchorage capacity. The study was based on 13 reinforced concrete beams that had been exposed to natural corrosion for 32 years, 11 beams with splitting cracks and 2 without. The crack pattern and widths were documented before undergoing structural testing of anchorage capacity. Thereafter, the reinforcement bars were extracted and their corrosion levels measured using two methods, gravimetric weight loss and 3D scanning. The corrosion level from the weight loss method was approximately twice as large; possible reasons are horizontal or subsurface corrosion pits, and the cleaning method. Further, for the same corrosion level, the specimens in this study had much larger crack widths and slightly lower bond capacity than the artificially corroded tests in the literature; a possible reason is that these specimens had been subjected to combined corrosion and freezing. However, the corrosion level and reduction in bond capacity related to crack width were both lower in the present than in previous studies in the literature. Thus, by formulating a damage indicator from the damage visible in the form of crack widths from artificial test data, the structural capacity is estimated to be on the safe side.

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