A case study has been chosen to impart a better understanding of the sustainable multicriteria decision-making (MCDM) approach for the selection of sustainable construction materials described in Chapter 4. The timber–concrete composite (TCC) floor system is a competent floor system that can take full advantage of the mechanical properties of both concrete and timber. Designing sustainable TCC floors involves several conflicting design criteria that must be considered simultaneously. The case study demonstrates an MCDM approach for weighting and ranking alternative TCC floors at the design stage. To set the criteria weights, a short survey was conducted on technical and production managers at industrialized house-building companies in both the Swedish and European markets. According to the MCDM results, the TCC floor with a 7.3 m span length belonging to comfort class A has the highest ranking and was chosen for the detail design stage as the results of the case study.

The demand for a sustainable built environment is no longer a matter of personal choice, and sustainability performances need to be integrated within all activities in the construction projects. Growing performance objectives, including sustainability with several conflicting performance criteria, impose the application of tools based on a multicriteria decision-making (MCDM) approach for ranking and selecting sustainable building materials to consider all performance criteria simultaneously. Because both weights of criteria and sensitivity of decisions significantly influence the outcome of the decision-making process, it is important to pay particular attention to both the consistency of judgments by the experts in the field and sensitivity analysis. MCDM approach must allow interfacing with other engineering tools to evaluate performance metrics. This chapter examines the process of ranking and selecting sustainable building materials using the MCDM approach and illustrates how sustainability performance can be integrated into the materials selection process for construction projects.

The building industry is one of the most resource-intensive sectors in industrialized countries, requiring a shift from a linear to a more sustainable circular economic model. Nevertheless, there are several major challenges, such as the management of information regarding used materials and products, the lack of cross-sector documentation tools, and sales operations for implementing a dynamic circular economy in the building industry. To overcome these challenges, blockchain technology for documentation, tracing used materials and products, and the use of multi-criteria decision-making approaches for the ranking and selection of optimal used materials and products have emerged as crucial facilitators, with the potential to address the technological, organizational, environmental, and economic requirements. The purpose of this study is to develop a theoretical framework of a digital platform ecosystem for implementing a dynamic circular economy in the building industry through the integration of blockchain technology and a multi-criteria decision-making approach built upon their synergy. The priority order of two alternatives of used materials and products was determined according to the AHP method, leading to selection of the most sustainable alternative. This research study contributes to dynamic circular economies by (1) facilitating cross-sector information transparency and the tracing of used materials and products from their sources to their end-of-life stages and through (2) the ranking and selection of used materials and products based on their overall properties.

Vibration performance of a one-way simply supported timber-concrete composite (TCC) floor section has been studied using analytical as well as numerical methods. Focal points have been verification and validation of results from analytical and numerical calculations of vibration response based on experimental data. For the analytical calculations, floor bending stiffness and vibrational response are determined from methods proposed in the current and revised versions of Eurocode 5. The numerical calculations based on the finite element (FE) method are done using 3D solid elements with orthotropic material parameters. When comparing the results of the FE analysis, better agreement with the experimental data is reached for the fundamental frequency when 3D solid elements are used rather than 3D beam elements. Furthermore, better agreement with the experimental data is reached for RMS acceleration by FE analysis rather than the method based on Eurocode 5. For detailed analysis, the authors suggest performing dynamic FE analysis and calculating vibration response from the TCC floor’s modal responses as eigenmodes and natural eigenfrequencies below 40 Hz. For future studies, it is recommended that the verification of vibration response may be accomplished by applying standard EN 16929.

This study aims to present a multi-criteria decision analysis (MCDA) for comprehensive performance evaluation of the alternative design of timber–concrete composite (TCC) floor system. Considered objectives are serviceability and sustainability performance with associated criterion as (1) comfort class regarding springiness and vibrations, (2) architectural quality with associated criterion as open spaces, (3) environmental aspect with associated criterion as CO2 emissions and (4) cost aspect with associated criterion as the total costs. Analytical Hierarchy Process (AHP) and Complex Proportional Assessment (COPRAS) as the methods in the multi-criteria analysis have been combined for (1) determining the weighting of criteria based on the survey results, (2) verifying the consistency ratio of decision matrix made by experts and (3) for ranking and selecting the optimal concept design among design candidates. According to the results, the TCC floor with the span length of 7.3 m belonging to comfort class A has got the highest ranking. However, sensitivity analysis indicates that the TCC floor with a 9.0 m span length belonging to comfort class A shall be selected as the optimal concept design. The study contributes by developing a complete concept design tool for TCC floor systems using AHP combined COPRAS methods to handle both beneficial and non-beneficial criteria.

Building Information Modelling (BIM) is claimed to transform the Architecture, Engineering and Construction (AEC) industry, whereas current research has argued that diffusion of BIM use proceeds at a slower rate than the optimistic predictions. Despite that potential of BIM is higher in industrialized housebuilding, the trade express similar characteristics as traditional construction both in terms of BIM sue but also organization of assets. The aim of this paper is to present a conceptual framework for digital development in industrialized timber housing. Data were gathered from eight industrialized housebuilding companies in a mixed approach with interviews, focus groups and a survey. The analysis presents the current use of BIM and digital tools and prioritized development areas within this domain. By adding a theoretical overview of current research for industrialized housebuilding with focus on platform strategies and digital development a framework is drawn. Problems with transfer in the interfaces between software were emphasized. Current research on developing a system for Product Lifecycle Management (PLM) in industrialized housebuilding indicate a path forward. A PLM system facilitates the development of digital developments such as digital twins and smart products, which possess the potentials to generate crucial feedback, which is crucial for the competitiveness and efficiency of industrialized housebuilding. Thus, for a trade with high levels of complexity, a move towards a fully functional PLM system might not only be desirable but decisive.

Samhällbyggnadssektorn står inför stora utmaningar inom den närmaste framtiden,bland annat med avseende på hur sektorns miljöpåverkan kan reduceras, samt hurkostnaderna för att producera bostäder kan minskas.Syftet med projektet har varit att utveckla, justera och förfina for tillfredställandeutformning av byggnadsstommar och konstruktionselement med fokus på klimat,materialkostnad och produktionstid. Ett första delmål i projektet har varit att utvecklametoder och verktyg för tillförlitlig och robust LCA- och LCCA beräkning. Andra delmålmed projektet har varit att ta fram en metodik för produktutveckling avbyggnadsstommar och konstruktionselement med fokus på livscykelperspektiv.Ett teoretiskt ramverk baserad på värdedriven metodik har utvecklats fördimensionering och analys av konstruktionselement och byggsystem. Teoretiskaramverket har använts för både analys av stommar med olika stabilitetssystem ochutformning av samverkansbjälklag av betong och trä i flervåningshus med optimalspännvidd. Fokus i utformningen har varit klimatpåverkan, byggkostnader,deformationer och vibrationer.

Long-span timber-concrete composite (TCC) floor systems have the potential to address the design challenges for conventional wooden floors in residential multi-storey timber frame buildings. The aim of this paper is to develop a design approach for long-span timber-concrete composite floor system of 6-9 m. A framework based on value-driven design approach has been developed for integration of results from graphical multi-objective optimisation, spreadsheet-based analysis, structural static and dynamic finite element analysis, and multi-criteria decision making. To verify the developed framework, a residential five-storey timber frame building as a case study has been studied. Optimal design includes optimised thickness of the concrete and optimised smeared stiffness of connectors for three different comfort classes A to C in descending order. TCC floor with span length 7.3 [m] belonging to comfort class A and TCC floor with span length 9.0 [m] belonging to comfort class C has been chosen as optimal solutions. The results indicate that proposed and innovative design approach is a promising tool for developers, architects and structural engineers when designing optimal long-span timber-concrete composite floor system.

In timber concrete composite (TCC) floor systems the concrete contributes to increase of the stiffness and research is ongoing to develop large span TCC floor systems with less supporting walls to create both modular flexibility and wide-open spaces. Nevertheless, removing supporting walls can degrade structural performance against horizontal forces (Ferdous, et al., 2019). Meanwhile both the height of the structure and the type of floor diaphragm (rigid or flexible) has influence on the magnitude of the lateral loads transferred to the supporting shear walls. This is a challenge, not least when prefabricated elements are used; the individual elements have to be connected to form a continuous floor diaphragm. The main aim of this paper is to study lateral load transferred to the shear walls through the TCC floor with both rigid and/or flexible diaphragms in low and medium-rise timber buildings. The focal point of the study is the analysis and design of floor elements and connection systems connecting the TCC floor elements to each other as well as to the adjoining structure. The case studies for low and medium-rise timber structures have been analyzed both using finite element modelling and analytical methods based on both deep beam theory and beam or diaphragm actions depending on the height of the structure. The results in this study indicate that the magnitude of load transferred to the shear walls depends on both the height of the structure and the type of floor diaphragms. The structural performance in terms of stability can be enhanced by effective use of connection systems of TCC floor elements.

Serviceability in terms of springiness, vibration and deflection [1], as well as sustainability in terms of climate impact and costs [2] have been identified as the most important aspects for appropriate functioning in residential multi-storey timber-buildings. Thus, the aim of this study is focused on product development of a timber-concrete composite (TCC) floor system by 1) enhancing serviceability performances of the floor for larger spans (above 6 m) in terms of stiffness and dynamic response, and 2) reducing both climate impact (CO2-emissions) and costs, by optimizing material usage. As the case study a timber structure of a residential multi-storey building, including concrete ground floor and shaft, with the overall dimensions ܮൈܹൈܪൌ30ൈ11ൈ14 ሾ݉ଷሿ has been studied. The geometry of the load bearing structural elements has been modelled using finite element programs. As serviceability criteria for the floors, the deflection due to a point load was chosen. The deflections were related to comfort classes given in [3] and transverse load distribution was taken into account according to [4]. The deflection and effective bending stiffness (EIef in EC5 Annex B) were chosen as objective functions, while thickness of concrete slab and shear stiffness of the connection between glulam beam and concrete slab were chosen as design variables in a multi-objective optimization. The relationship between connection stiffness and height of the concrete slab for comfort class B can be seen in Figure 1. In the figure the cross-section of the TCC floor structure, with a span of 7.5 m, is also depicted. Figure 1: Connection stiffness-concrete thickness relationship and cross-section for the TCC floor. After optimization, a multi-criteria analysis was applied to select a design solution from the Pareto optimal front, satisfying some subjective preferences of the stakeholders for value-driven design. The results in this study integrates serviceability, environmental and economic performances for value-driven design and supports decision making in the early phases of a project, where various alternatives can be analyzed and evaluated.

To improve organizational decision-making process in construction industry, a framework of a multi-objective andmulti-criteria based approach has been developed to integrate results from Life-Cycle Analysis (LCA), Life-Cycle CostAnalysis (LCC) and dynamic analysis for multi-storey industrialized timber structure. Two Building InformationModelling (BIM)-based 3D structural models based on different horizontal stabilization and floor systems will beanalyzed to reduce both climate impact, material and production costs and enhance structural dynamic response of thefloor system. Moreover, sensitivity of the optimal design will also be analyzed to validate the design. The multi-objectiveand multi-criteria based LCA-LCC framework analyzing the environmental, economic, and dynamic performances willsupport decision making for different design in the early phases of a project, where various alternatives can be created andevaluated. The proposed integrated model may become a promising tool for the building designers and decision makers inindustrialized timber construction.

Building Information Modelling (BIM) is claimed to transform the Architecture, Engineering and Construction (AEC) industry, whereas current research has argued that diffusion of BIM use proceeds at a slower rate than the optimistic predictions. Much of the research on BIM has focused on the traditional part of the industry and larger companies, whereas less attention has been paid to the industrialized house-builders. The underlying idea of industrialized house-building is to increase efficiency, both internally (do things right) and externally (do the right things), with repetitiveness in production facilities. Previous research indicates that there is a lack of demand for BIM, both internally and externally, and that BIM use is rather determined by an individual’s subjective positive or negative evaluation of BIM, which may be hazardous for industrialized house-builders. However, using BIM in repetitive processes is claimed to have potential to improve the output of industrialized housing building.

Hence, based on this background the aim of the paper is twofold: Firstly, to explore the current state of practice, and perceived constraints and driving forces of BIM-use with respect to industrialized house-building. Secondly; based on the results identify key areas for the continuous development of BIM within this sector of the construction trade. A mixed method approach was employed. To begin with, participant observations were carried out in connection to a regional development project, where managers from a selection of industrialized house-building companies assembled in order to identify key areas for development. Thereafter, interviews with managers in industrialized house-building companies were conducted to describe a state of practice within the industrialized house-building sector. Finally, a survey (n=52) was administered to employees at industrialized house-building companies on the Swedish market.

Deducted from the observations at the meetings, the vast number of different software that are used in a large variety of different processes and the need for integration between BIM and other systems was highlighted. Discussions mostly concerned technical issues that can be explained by the fact that meetings participants were technical and development managers. The interviews gave at hand that better connection between BIM and the Enterprise Resource Planning (ERP) is a topic that should be prioritized. The results from the survey showed that 63 per cent of the respondents have experience from working with BIM. The immediate results show similarities with previous studies of BIM use among mid-sized firms in the traditional building and construction industry regarding use frequency, perceived benefits and constraints, as well as perceived challenges. However, it is concluded that the industrialized house building sector need to adapt BIM aligned to their unique conditions in order to reap benefits, without looking too much at what is going on in the traditional construction industry.

Purpose - The objective is to study the optimal damper placement of a given number of passive viscoelastic dampers, when the structure (nuclear plant) is subjected to motions from earthquake, in order to reduce the acceleration responses at a particular location, for example, a vibration-sensitive room (nuclear reactor).

Design/methodology/approach - The IDESIGN software including genetic algorithms for the optimisation task has been interfaced with a finite element program, ABAQUS, to create a structural optimisation tool. The tool has been tested on a 3D building structure.

Findings - Optimisation results for different constraints on number of dampers shows that eight optimally located dampers results in an overall maximum reduction of 59 per cent of the cost function for the uncontrolled structure. It is also found that six optimally placed dampers are more effective than the fully damped case with 12 dampers.

Research limitations/implications - More powerful computers are needed in order to reduce the computational time for many engineering models. Especially parallel processing would make more efficient use of the genetic algorithm. It is also necessary to perform stochastic finite element analysis to investigate the impact on the cost function due to different earthquakes. Practical implications - The study of vibration reduction by an optimal number and location of viscoelastic dampers indicate that structures subjected to dynamic forces can be designed both safely and economically.

Originality/value - The tool developed is quite general and is believed to be applicable to many types of structural optimisation analyses.

In order to solve vibration problem in large-scale structures a global optimization program based on genetic algorithms has been integrated into an existing local optimization tool consisting of a commercial finite element program and a local optimization program based on gradient methods. The developed optimization tool has been tested on a 3D structure for vibration reduction purposes using seismic load as excitation forces.

During the construction of the New Svinesund Bridge, a monitoring project is conducted on behalf of the Swedish road administration (Vägverket). The Royal Institute of Technology (KTH) is leading this project and is responsible for instrumentation, analysis and documentation in the project. As a part of the monitoring project, a finite element model was accomplished at Chalmers University of Technology, department of structural Engineering and Mechanics. Parallel to the monitoring project, a project concerning bridge assessment and maintenance based on FE analysis and field measurements was initiated at Chalmers University of Technology (Chalmers) on behalf of the Swedish road administration (Vägverket) and the Swedish railway administration (Banverket). The FE model was further developed within this project. The model is intended to be used both by the Royal Institute and Chalmers in their further work with the bridge. A finite element (FE) model of the New Svinesund Bridge was developed, and a simplified analysis of the construction of the bridge was made. The FE model was based on the structural model made by the bridge contractor, Bilfinger Berger (2004). The FE model was verified through comparisons with results obtained from the contractor, using the design model of the bridge. Eigenfrequencies and eigenmodes for different stages during the arch launching were calculated. These were found to correspond reasonably well to what was calculated by Bilfinger Berger, even though the FE analysis gave a little lower eigenfrequencies. The completed bridge was analysed for distributed external loads on the carriageways. The sectional moments and forces in the arch, obtained in the FE analysis showed a good agreement with the results from Bilfinger Berger. The deformations of the arch showed a reasonably good agreement between the models.