The discussions on digital twins (DT) have greatly increased, and this technology is believed to solve many of the engineering and construction (E&C) industry’s problems. However, there is a significant gap between this perceived potential and the maturity level of practical applications. The proliferation of context-specific frameworks for each DT project hinders the widespread adoption of DTs across the industry. This paper aims to shift the focus from individual DT frameworks to viewing DT as a tailored pack of existing technologies, chosen according to the purpose of the digitalisation initiative. A purpose-driven roadmap for DT adoption in the E&C industry is introduced to bridge the gap between perceived potential and practical applications. The methodology of this study comprises a literature review, DT investigation, and a case study analysis. The stages of the proposed roadmap stages include assessment, purpose definition, technology selection, implementation, and optimisation. The roadmap is validated, and its application is demonstrated through a case study of a reinforced concrete chimney in Sweden, where two longitudinal cracks had been previously identified. The conclusion highlights findings and future directions, emphasising the roadmap’s role in fostering a flexible and impactful adoption of DTs in the E&C industry.

Demonstrating the performance of a structural component is typically accomplished through calculations based on engineering models. However, advancements in material science have enabled the use of new materials in the construction industry. One example is fibre-reinforced concrete, which consists of concrete with short, discontinuous fibres dispersed throughout its volume to enhance performance under service limit states. The absence of conventional reinforcement can affect ductility and load capacity, making calculations alone insufficient to demonstrate the performance of these elements. Therefore, load-testing programs need to be developed. This paper reports and discusses the results of a full-scale test on a fibre-reinforced concrete multi-span slab-on-piles. The development of the test program, including the loading setup to achieve failure loads, is presented. The slab's performance is evaluated in terms of deflections and crack widths at various loading intervals corresponding to both service limit states and ultimate limit states.

The use of digital twin (DT) technology within the engineering and construction (E&C) industry is valuable for practical applications in asset management of structures. Functional DT in E&C, however, are still in initial stages of development. Efforts towards standardization of concepts and procedures are necessary to build on existing knowledge and drive progress further on functional DT. This paper proposes a DT of a snow gallery, part of the Iron Ore railway in northern Sweden. The gallery was instrumented with a structural health monitoring (SHM) system that feeds data in real time to the DT, which also includes a 3D model of the gallery. The proposed methodology can be replicated to different structures and scaled for larger amounts of data. The SHM data and the 3D digital model of the snow gallery are connected in a single, integrated platform that enables improved decision-making for maintenance of the gallery. To promote clarity and progress within the field, the proposed DT’s maturity level is classified in terms of autonomy, intelligence, learning, and fidelity. The snow galleries, the SHM system, and the proposed DT are all presented and discussed, following a brief review on DT, the importance of level classification, and predictive maintenance.

The Herøysunds bridge on the west-coast in Nordland Fylke in Norway had undergone concrete repair works with focus on reinforcement corrosion. During these actions, it was discovered that the tendon ducts had loss of injection.

To ensure the safety of the bridge it was decided to map voids and defects in the ducts. Several risk areas were pointed out by the contractor and a non-destructive test (NDT) was carried out. The scope of the NDT inspection was to determine voids in the cable ducts at the areas which had been pointed out by the designer. In the project we followed a strict procedure. Based on this we used a combination of different methods such as GPR (Ground Penetrating Radar), UPE (Ultra Pulse Echo) and IE (Impact Echo). It should be mentioned that considerable experience is needed when these methods are combined to investigate voids and defects in tendon ducts. In addition, it is difficult to determine the degree of grouting in the duct and the NDT methods often need to be combined with partly destructive testing, i.e. a hole needs to be drilled into the duct and closer investigation with for example endoscope might be needed. The results from the NDT investigate shows that the suggested approach was successful and it was possible with high accuracy to detect voids in the ducts. The methodology forms a basis for the procedure recommended by the Norwegian Public Roads Administration.

Digital Twins (DT) have become a widely discussed subject, believed to have the potential to solve various problems across different industries, including Engineering & Construction (E&C). However, there is still significant misconception concerning the definition of DT and their purpose within E&C. This study dives deep into identifying DT applications within E&C and the other prominent industries, i.e., Aerospace & Aviation, Manufacturing, Energy & Utilities, Automotive, Healthcare, Smart Cities, Oil & Gas, and Retail. The main challenges to the evolution of DT practical applications are also analyzed. A combination of literature review, multi-case study analysis, and comparative analysis compose the deployed methodology. Standardization and a maturity level classification are proposed to drive progress of the adoption of DT. The distinct aspects of the different industries and their assets are evaluated to the conclusion that DT are better employed to maintenance of structures within E&C. DT have become a well-worn topic, but the abundance of complex theoretical frameworks is met with simple or inexistent practical applications. Therefore, the novelty of this study lays in its comprehensive analysis of DT applications and real-world implementations – a departure from the often-theoretical discussions surrounding DTs.

Self-stressing steel fibre-reinforced concrete (SFRSSC) is increasingly utilised every day, with its areas of applicability expanding. One such application is ground-level elevated slabs on piles, along with elevated slabs on columns. Although regular steel fibre-reinforced concrete (SFRC) has been previously applied for such cases, albeit somewhat extensively, very few full-scale load-bearing tests have been conducted for these slabs under industrial-level loads up to failure. In Northern Europe, the use of SFRC in ground-level elevated slabs is somewhat common, either with or without additional traditional rebar reinforcement. On the other hand, SFRSSC is still an emerging technology with known benefits, and parts of the technology are yet to be discovered. No calculation method exists to validate the benefits of SFRSSC, specifically the self-stressing impact on load-bearing capacity at the ultimate limit state (ULS) and behaviour under serviceability limit state (SLS) loads. The aim of this presentation is to provide an overview of a comparative full-scale load-bearing capacity test up to failure, comparing two elevated slabs made of regular SFRC and SFRSSC loaded under similar conditions. Material properties were monitored by conducting an extensive battery of laboratory tests. The deformations, cracking, and shrinkage of the full-scale slabs were recorded using both standard sensors and innovative technologies, such as fibre optic sensors embedded in concrete and the digital image correlation method. The slabs were loaded with uniformly distributed sandbags up to the SLS load, and SLS criteria were measured. After unloading, the ULS load was applied; the slabs were evaluated and further loaded up to failure. The test results show that the slab made of SFRSSC had smaller deflections and crack widths, as well as a significantly higher load-bearing capacity.

The Herøysunds bridge on the west-coast in Nordland Fylke in Norway had undergone concrete repair works with focus on reinforcement corrosion. During these actions, it was discovered that the tendon ducts had loss of injection. To ensure the safety of the bridge it was decided to map voids and defects in the ducts. Several risk areas were pointed out by the constructor and a non-destructive test (NDT) was carried out. A methodology with combin-ation of different NDT methods were used; cover meter, GPR, UPE, IE and Videoscope. The results from the NDT investigate shows that the suggested approach was successful, and it was possible with high accuracy to detect voids in the ducts. The methodology forms a basis for the procedure recommended by the Norwegian Public Roads Administration.

The construction industry has a significant impact in terms of financialand environmental resources but is vastly behind other sectors in terms of digitalization.The potential of this industry to be improved by new technology has beenreflected in huge trends in research for terms such as “digital twins”. However, thepurpose of such technologies and how they can be applied to specific needs andassets in the construction sector is not always clear. This paper proposes an analysisof the purpose, current and future states of digital twins in the constructionindustry, based on a reviewof the evolution of research in the topic and recentmarketapplications. Even though there is a discrepancy between research and levelof development of tangible applications, it is undeniable that the digital transformationwill reach the construction industry. The efforts should then be focusedon technology that can be translated to its assets, such as smart management, andwill generate tangible results that can survive outside the theoretical realm.

Demonstrating the performance of a structural component can usually be done through calculations based on engineering models. However, the development in material science has made it possible to use new materials in the construction industry. One such example is the use of fibre-reinforced concrete defined as concrete containing short and discontinuous fibres dispersed throughout the concrete volume in order to improve the performance in service limit state. The lack of conventional reinforcement may affect the ductility and load capacity, and the calculations alone may not be sufficient to demonstrate the performance of these elements. Load-testing programs are therefore needed to be developed. The current paper reports and discuss the results of a full-scale test on a fibre-reinforced concrete multi-span slab-on-piles. The development of the test program including the loading setup to achieve the failure loads are presented. The performance of the slab is evaluated in terms of deflections and crack widths at certain loading intervals that corresponds with service limit state as well as ultimate limit state.