Beständigheten hos klimatskalets lufttäthetsystem är helt avgörande för om näranollenergihus, passivhus och plushus kommer att fungera som det var tänkt över tid. Eftersom produkterna som säkerställer lufttätheten oftast befinner sig inuti konstruktionen kan det därför innebära stora ingrepp i byggnader om de behöver bytas ut i förtid. Att i laboratorium i förväg kunna utvärdera beständigheten hos det lufttätande systemet är viktigt och för detta behövs en provningsmetod.

Det överordnade syftet med hela projektet är att utveckla en metod där hela system för lufttäthet kan undersökas. Detta så att god lufttäthet och låg energianvändning kan erhållas under lång tid hos framtidens lufttäthetssystem. Denna etapp av projektet har innehållit utveckling och provkörning av en ny provningsmetod. Provningsmetodiken har dokumenterats i SP-metod 5264, utgåva 2, bilaga 2 till denna rapport. Provningsmetoden har fungerat ypperligt vid pilotprovningarna. Man ser en förändring av lufttätheten vid mätningar före respektive efter värmebehandlingen. Provningsmetoden är mycket noggrann och känslig på så sätt att förändring i lufttätheten kan registreras.

Provningsmetoden är ett mycket bra verktyg för producenter av lufttäthetssystem vid produktutveckling. Metoden är också lämplig för användning vid utvärdering av lufttäthetssystem för olika godkännandesystem och certifiering. Samtliga provade lufttäthetssystem var mycket lufttäta före värmebehandlingen. Alla systemen visar på resultat under 0,1 l/(s∙m²). Efter värmebehandlingen visar alla undersökta lufttäthetssystem dock en ökande luftgenomsläpplighet, i varierande grad.

I projektet har även montage av lufttäthetssystem gjorts i miljöer som valts för att efterlikna realistiska byggarbetsplatsförhållanden. Alla de undersökta lufttäthetssystemen visar på förändringar i lufttätheten då montaget har skett i kall och fuktig miljö och vid montage i dammig miljö. Variationen mellan de olika systemen har dock varit ganska stor.

Det är vår uppfattning om alla lufttäthetsystem i framtiden undersöks med hjälp av denna provningsmetod så kommer man att få en stark förbättring av lufttätheten och därmed lägre energianvändning.

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Development of methodology for verification of the durability of systems for airtightness, stage 1 This is a project that is intended to treated durability of airtightness systems for buildings with typically related details, such as foil, tape, prefabricated lead-through, etc. This stage of the project has included the development, design and construction of prototype equipment. This is so that dimensioning, heating method, the level of dynamic loading, etc. could be selected and tested. Some shorter pilot tests of dimensions stability have been performed and testing methodology has been documented.

Syftet med denna rapport har varit att redogöra för vad som krävs när man skall bygga eller renovera våtrum på ett fuktsäkert sätt. Eftersom det finns många olika typer av konstruktioner, material, förutsättningar och tätskikt är det svårt men framför allt tidsödande att göra rapporten heltäckande. Vi har dock försökt att med dagens kunskap ta fram ett dokument där helheten är överskådlig men som även ger information om de viktigaste detaljkunskaperna från vår fältverksamhet och tidigare utförda forskningsprojekt.

Functional testing of waterproofing systems for use behind ceramic tiling based on flexible sheets 2019

Functional testing

The result is worse than before.

Six (32%) of the nineteen tested waterproofing systems passed the function test without leakage. Thirteen (68%) tests resulted in leakage.

This result is worse than that obtained in the previous project in 2016, (1) when eight (40%) of twenty tested waterproofing systems passed the functional test without leakage. There has therefore been some deterioration in the as constructed systems.

The result, however, is better than in the project performed in 2014 (2) when only three (15%) of twenty tested waterproofing systems passed without leakage.

In this project, several leakages are localised around the penetrations of large and small drainpipes. This is an increase compared to previous studies. We have seen on several occasions that pipe collars have had poor quality. This has been noticed by that the polymer material used for sealing around the tube has lost its water tightness ability during the test. It is most probable that the material has a residual deformation (from setting) that causes the material to lose its ability to seal around the tube. We have also noted that the pipe collars have delaminated i.e. the layers in the collars have been divided into their individual constituents during the test.

Leakages have also been caused by connections to gullies, inside corners, outside corners and in joints of foils.

Fortunately, none of the investigative systems showed leakage that was so extensive that one could describe it as total damage.

Water vapour resistance and mass per unit area

Thirteen tested waterproofing on flexible sheet systems show a result between 2,5 and 4,5 million s/m, which is a high or very-high water vapour resistance. Six flexible sheet systems have a result below 2,5 million s/m.

In the determination of water vapour resistance and mass per unit area, we can clearly see that some manufacturers have made changes in or replaced their flexible sheet with a new one, compared with the previous investigation (1).

We further note that 10 out of 14 flexible sheets have a lower water vapor resistance than in the previous investigation (1). It is also notable that the PVC sealing layer has a low water vapor resistance.

Indication of long-term properties

In order to obtain an indication of the amount added antioxidants that improves the long-term properties of the materials, the DSC analysis of flexible sheets have been performed. In the same way as in the previous project, 2016, (1) it seems that the flexible sheets to be more stabilized for long-term use compared to the previous study in 2014, (2). However, for all analysed materials, to make a reliable service life prediction of the material, an accelerated ageing at moderate temperature is recommended.

In this paper a precise model is established for deflection prediction of mechanically jointed beams with partial composite action. High accuracy of the proposed method is demonstrated through comparison with a comprehensive finite element (FE) modelling for a timber-concrete partial composite beam. Next, the obtained numerical results are compared with gamma-method, a well-known simplified solution for timber engineers according to the Eurocode 5. Validity and accuracy level of the gamma-method are investigated for various boundary conditions as well as different values of beam length-to-depth ratio, and discussed in details.

Given their intrinsic features, adaptive facades are required to satisfy rigid structural performances, in addition to typical insulation, thermal and energy requirements. These include a minimum of safety and serviceability levels under ordinary design loads, durability, robustness, fire resistance, capacity to sustain severe seismic events or other natural hazards, etc. The overall design process of adaptive facades may include further challenges and uncertainties especially in the case of complex assemblies, where multiple combinations of material-related phenomena, kinematic effects, geometrical and mechanical characteristics could take place. In this context, experimental testing at the component and/or at the full-scale assembly level has a fundamental role, to prove that all the expected performance parameters are properly fulfilled. Several standards and guideline documents are available in the literature, and provide recommendations and procedures in support of conventional testing approaches for the certification and performance assessment of facades. These documents, however, are specifically focused on ordinary, static envelopes, and no provisions are given for the experimental testing of dynamic, adaptive skins. In this regard, it is hence expected that a minimum of conventional experimental procedures may be directly extended from static to dynamic facades. However, the validity of standardized procedures for adaptive skins is still an open issue. Novel and specific experimental approaches are then necessarily required, to assess the structural characteristics of adaptive facades, depending on their properties and on the design detailing. In this paper, existing fundamental standards for testing traditional facades are first recalled and commented. Special care is spent for the validity and reliability of conventional testing methods for innovative, adaptive envelopes, including a discussion on selected experimental methods for facade components and systems. Non-conventional testing procedures which may be useful for adaptive skins are then also discussed in the paper, as resulting from the research efforts of the European COST Action TU1403 ‘Adaptive facades network’ - ‘Structural’ Task Group.

Adaptive facades are increasingly used in modern buildings, where they can take the form of complex systems and manifest their adaptivity in several ways. Adaptive envelopes must meet the requirements defined by structural considerations, which include structural safety, serviceability, durability, robustness and fire safety. For these novel skins, based on innovative design solutions, experimentation at the component and / or assembly level is required to prove that these requirements are fulfilled. The definition of appropriate metrics is hence also recommended. A more complex combination of material-related, kinematic, geometrical and mechanical aspects should in fact be properly taken into account, compared to traditional, static facades. Accordingly, specific experimental methods and regulations are required for these novel skins. As an outcome of the European COST Action TU1403 ‘Adaptive facades network’ - ‘Structural’ Task Group, this paper collects some recent examples and design concepts of adaptive systems, specifically including a new classification proposal and the definition of some possible metrics for their structural performance assessment. The aim is to provide a robust background and detailed state-of-the-art information for these novel structural systems, towards the development of standardised and reliable procedures for their mechanical and thermo-physical characterisation.

In this study, the physical and mechanical properties of plywood panels made from pre-compressed birch (Betula verrucosa Ehrh.) veneer were evaluated. Veneer sheets underwent short-term thermo-mechanical (STTM) compression at temperatures of 150 or 180 °C and at pressures of 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 or 3.5 MPa for a period of 1 min prior to adhesive being applied and pressed into panels using phenol formaldehyde adhesive at 100 g/m2 spread rate; this was one-third less than the adhesive spread used for the control panels (150 g/m2). The pressing pressure was 1.0 MPa, which was almost half of the pressure used for the control panels (1.8 MPa); and pressing time was 3 min, also half of the pressing time used for the control panels (6 min). The results showed that surface roughness of compressed veneer, water absorption and thickness swelling of plywood panels made from compressed veneer were significantly improved. The shear strength values of plywood panels made from compressed birch veneer even with reduced adhesive spread were higher than those of plywood panels made from uncompressed veneer. The findings in this study indicated that compression of birch veneer could be considered as an alternative to produce more eco-friendly (owing to smaller adhesive spread) value-added material with enhanced properties.

Diffusion kinetics and structural properties of chemically strengthened titania-doped soda-lime silicate glasses were studied by depth-resolved X-ray photoelectron spectroscopy, Raman spectroscopy and spectrophotometry.

Chemical strengthening (CS) is frequently used to strengthen thin glasses. CS of glass is based on ion exchange of larger ions from a molten salt into glass. Both the ion and counter ion are conventionally monovalent alkali ions.

Diffusion kinetics and structural properties of chemically strengthened titania-doped (TiO2) soda-lime silicate (SLS) glasses were studied by depth-resolved X-ray photoelectron spectroscopy, Raman spectroscopy and spectrophotometry. The glasses were ion exchanged, whereby Na+ in the glass was replaced by K+ in a molten salt bath, at four different treatment temperatures between 350 and 500 °C.

The following samples were prepared and analyzed by X-ray Photoelectron Spectroscopy (XPS): (1) SLS, (2) 4.7% TiO2, and (3) 9.9% TiO2. The ion exchange procedure was performed for 5 h at four different temperatures below Tg (350, 400, 450 and 500 °C). Before XPS measurements, the samples were wet-etched using hydrofluoric (HF) acid to produce samples with six different etching depths.

The Raman scattered light was detected in the backscattering configuration employing linear polarization and 2400 lines/mm grating, and a 100x objective lens. Depth profile spectra were collected at six different depths of 0, 10, 20, 30, 40, and 50 µm for each glass sample, employing 12 scans with a 10 s exposure time for each scan.

Spectrophotometric measurements were conducted before and after K+/Na+ ion-exchange treatmeatment for 5 h at 500 °C, collected between 300 and 2500 nm.

One challenge of monitoring and inspecting timber bridges is the difficulty of measuring the moisture content anywhere other than close to the surface. Damage or design mistakes leading to water penetration might not be detected in time, leading to costly repairs. By placing electrodes between the glulam beams, the moisture content through the bridge deck can be measured. Due to the logarithmic decrease of the resistance in wood as a function of electrode length, the model must be calibrated for measurement depth. Two models were created: one for electrode lengths of 50 mm and one for electrode lengths up to 1355 mm. The model for short electrodes differed by no more than 1 percentage points compared with the oven dry specimens. The model for long electrodes differed up to 2 percentage points for lengths up to 905 mm, and over that it could differ up to 4 percentage points.

Practicing structural engineers may be familiar with the main principles of structural reliability but may not necessarily be experts in using such methods. This may lead to a lack in understanding the effect of uncertainties on the ensuing structural safety and to sub-optimization of more traditional structural engineering aspects. The aim of the current paper is to highlight the importance of considering risks and uncertainties in design and to improve the awareness of practicing engineers to such considerations. The importance of a consistent treatment of uncertainties in structural engineering is brought to attention with focus on the modelling approaches which often underlie decisions. Different aspects discussed are: decision making in light of uncertainty, principles of consistent crudeness and the influence of engineering performance in practice on the safety of structures. A simplified model, considering strategies for improving engineering models, is considered and examples, based on simplified decision models, are also provided.

An essential aspect in the maintenance of existing bridges is the ability to adequately and accurately assess and evaluate the condition of the structure. Condition assessments, which can be carried out in any number of ways, provide valuable information concerning the actual state of a bridge, including the severity of potential damages, and form the basis for further maintenance decisions. Any decision support concerning the management of existing structures thus requires attention towards the uncertainties associated with the assessment methods when applied in practice as well as the maintenance actions these support. These uncertainties cannot be solely described as model uncertainties but are also a result of the variation in engineering performance observed in practice. In the current paper a rational and systematic framework is presented which provides practical decision support concerning whether condition assessments are necessary, what assessment methods are recommended, if invasive actions are needed, or if some other non-invasive option may be more appropriate. The framework takes into account three main attributes of an enhanced condition assessment, namely, modelling sophistication, considerations of uncertainties and risks, and knowledge/information content. Increasing the level of one or more of these attributes may be advantageous only if the expected benefits or added value of information is considered appropriate in relation to the cost of implementation in practice. A decision making model, based on Bayesian decision theory, is adopted to evaluate this problem. Two case studies, in which the framework is applied, are provided for illustrative purposes; the first is a generic numerical example and the second a decision scenario related to the fatigue assessment of an existing railway bridge.

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.

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.

A shortcoming of the laminated bending process is that the product may become distorted after moulding. This study focused on the influence of fibre orientation deviation for individual veneers on the distortion of a moulded shell. The distortion of 90 cross-laminated shells of the same geometrical shape, consisting of seven peeled birch veneers, were studied under relative humidity variation. All the veneers were straight-grained in the longitudinal-tangential plane, but to simulate a deviation in fibre orientation, some of the individual veneers were oriented at an angle of 7 degrees relative to the main orientation of the other veneers in the laminate. A finite element model (FEM) was applied to study the possibility of predicting the results of a practical experiment. The study confirms the well-known fact that deviation in fibre orientation influences shape stability. The results also show how the placement of the abnormal veneer influences the degree of distortion. From this basic knowledge, some improvements in the industrial production were suggested. However, the FE model significantly underestimated the results, according to the empirical experiment, and it did not show full coherence. The survey shows the complexity of modelling the behaviour of laminated veneer products under changing climate conditions and that there is a great need to improve the material and process data to achieve accurate simulations. Examples of such parameters that may lead to distortion are density, annual ring orientation in the cross section of the veneer, the orientation of the loose and tight sides of the veneer, and parameters related to the design of the moulding tool.

There is a deficit of housing in Sweden and it is built too little to compensate for this according to the National Board of Housing, Building and Planning, which, among other things, indicate resource shortages as a reason.

The furniture and construction industry have much in common. However, the furniture industry has a larger share of industrial production, which means production at a lower cost. By retrieving production ideas in other industries, there is an opportunity to radically renew and transform the (wood) construction industry and thus streamline the construction process. Historically, cross-sectoral spin-off effects have been shown to generate success factors.

The goal of this project is to develop prototypes for building connections inspired by the furniture and interior industry and explore them together with industry actors. This, in turn, serves as an inspiration for a larger project, together with industry actors aiming at developing systems for assembly of building elements, which provide higher precision and are faster to perform than today's system. The pilot developed in this project shows that the idea is ripe for a more full-scale investigation.

Plasterboard is a common building material used in several parts of a building. In the case of retrofitting and demolition a part of the waste consists of components combined with the plasterboards, for example, frame work timber.

In the case of new construction and retrofitting, construction waste is produced from clean plasterboard boards, either as cut off pieces or as unused whole boards. This waste can be used as raw material to produce new plasterboards. Manufacturers want to use gypsum from wasted boards to decrease the use of primary gypsum from mining and the quality requirements are relatively easy to achieve.

In this project it has been found that the major construction companies already handle gypsum from new construction separately. This waste fraction could already be used in the production of new boards. Gypsum from retrofitting is usually assembled with other building materials and require more extensive efforts to achieve necessary purity to be used in the productions of new boards. Today, plasterboard waste is deposited or used to improve soil and/or sludge. In order to increase the recycling of plasterboards new inventory routines of rebuilding and demolition projects need to be elaborated. New tools and methods for dismantling plasterboard need to be development to achieve safe working environment and environmentally and economically sustainable recycling.

Preparation plants producing raw material from plasterboard waste are already in operation. Today the waste mainly is wastage from the production stage. In order to increase the recycling of plasterboards from the construction- and demolition branch new logistic systems need to be developed, for example by creating collection points for gypsum board waste and / or developing new transport vehicles and systems. Prerequisites of changing the system of piece work in the construction industry need to be investigated with the intension to create a more sustainable building industry.

Det europeiska fastighetsbeståndet är i behov av omfattande renoveringar för att uppnå minskade koldioxidutsläpp, men också för att skapa förbättrade livsvillkor för människor samtidigt som fastighetsägare drivs av ökad ekonomisk bärkraft. Men det är inte alltid lätt att veta hur mål av detta slag ska uppnås och balanseras. Därför har RISE tillsammans med partners i fastighetsbranschen tagit fram Renobuild – en beslutsmetod för att utvärdera renoveringar utifrån ett hållbarhetsperspektiv. I projektet har två versioner av metodiken tagits fram, testats och vidareutvecklats via fallstudier.

Med hjälp av Renobuild Bostad utvärderas renoveringar av flerbostadshus och deras omgivningar med hänsyn till klimatpåverkan, livscykelkostnader och sociala faktorer så som trygghet, säkerhet, hälsa och sociala relationer. Med Renobuild Skola utvärderas skolrenoveringar och dess effekter på inte bara ekonomi och miljö, utan också med hänsyn till elevers lärande, trygghet och sociala relationer. Metodiken genererar en sammantagen hållbarhetsvärdering som ska ge fastighetsägare och samarbetspartners fördjupad förståelse för möjliga hållbarhetskonsekvenser av olika renoveringsalternativ samt tillfälle att diskutera och göra avvägningar mellan olika mål.

Renobuild består av en Excelfil och en användarhandbok fritt tillgängliga för vem som helst att använda. Dessa nås via en webbplats, tillsammans med bakgrundsmaterial för den som vill få en djupare förståelse för hur metodiken har utvecklats. Förhoppningen är att metodiken nu ska spridas i fastighetsbranschen och därmed generera en större medvetenhet om hållbarhetsfrågor vid renoveringar.

Fastighetsbeståndet i Sverige och resten av Europa är i behov av omfattande renoveringar för att uppnå minskade koldioxidutsläpp, skapa förbättrade livsvillkor för människor och öka dess ekonomiska bärkraft. Men det är inte alltid lätt att veta hur dessa mål ska uppnås och balanseras. Därför har RISE tillsammans med partners i fastighetsbranschen tagit fram Renobuild – en beslutsmetod för att utvärdera renoveringar utifrån ett hållbarhetsperspektiv. I projektet har två versioner av metodiken tagits fram, testats och vidareutvecklats via fallstudier. I Renobuild Bostad utvärderas renoveringar av flerbostadshus och deras omgivningar. Analysen tar hänsyn till klimatpåverkan, livscykelkostnader och sociala faktorer så som trygghet, säkerhet, hälsa och sociala relationer. Renobuild Skola utvärderar skolrenoveringar och dess effekter på ekonomi, miljö och sociala aspekter så som elevers lärande, trygghet och sociala relationer. Resultatet ger en sammantagen hållbarhetsvärdering som fördjupar fastighetsägares och samarbetspartners förståelse för möjliga konsekvenser av olika renoveringsalternativ. Renobuild består av ett Excelark och en användarhandbok som är fritt tillgängliga för vem som helst att använda. Dessa nås via en webbsida tillsammans med bakgrundsmaterial. En del av det materialet är den här rapporten som ämnar ge en djupare förståelse för hur metodiken har utvecklats. Rapporten beskriver vad användaren kan utvärdera med hjälp av dessa verktyg, hur verktyget behandlar indata, hur resultatet framställs och visualiseras samt hur den nya version 2.0 skiljer sig från en tidigare version. Här beskrivs också hur bakgrundsdata och teori har används för att utveckla innehållet i verktygen. Dessutom diskuteras det vilka avgränsningar som har gjorts i den miljömässiga, ekonomiska och sociala analysen – alltså reflektioner kring systemgränserna för respektive hållbarhetsdimension. Förhoppningen är att metodiken ska spridas i fastighetsbranschen och därmed generera en större medvetenhet om hållbarhetsfrågor vid renoveringar.

Bioeconomy helps to move to a renewable, fossil-free future. The environmental impact is significantly reduced when replacing products made from fossil resources with bio-based alternatives. In a bioeconomy, all products are made from renewable and biogenic resources. In the building sector examples for biogenic sources are traditionally wooden building structures, while green roofs are becoming more popular. The goal of the present project is to assess the amount of biogenic carbon stored in green roofs and wooden buildings overall. The question is if green roofs are improving the biogenic carbon usage of buildings and find out how that can be improved. The methods used are based on construction modelling, life cycle assessment and standardised environmental product declaration (EPD). The results indicate that wooden building structures are not enough for a complete biogenic building to move to a renewable, fossil-free future. Furthermore, the biogenic benefits of green roofs do have a potential, while seen over the whole building the benefits are negligible, since half of the carbon in green roofs material composition is fossil-based. The results are presented as renewable and fossil-based energy as well as biogenic and fossil carbon. These are compared with conventional roofing based on non-renewable standard roofs in Sweden.

Dowel-type connections in timber structures should be typically designed in a way that, if the load bearing capacity is exceeded, desirable ductile failure should likely occur, i.e. yielding of the metal dowel or embedment of the timber. However, the probability of brittle failures cannot be completely avoided in many cases. If the connection is loaded parallel to the grain direction, splitting, row-shear, plug/block shear and tensile failure are examples of such brittle failure modes. To ensure a beneficial structural performance locally and sufficient structural robustness globally, the probability of such brittle failures should be kept at a sufficiently low level. However, in the current version of EN1995, the probability of such failure is not considered explicitly. The final aim of the presented research study is to develop a rational approach for the consideration of brittle failure in timber connections with dowel-type fasteners and steel plates loaded parallel to the grain, consistently with the partial factor method. As a first step, a probabilistic model has been used to study the susceptibility to brittle failure and provide a rational basis for the calibration of a “brittle overstrength factor”. The results of this study are reported in the current contribution.

Background Risk of indoor exposure to volatile organic compounds of purported microbial origin on childhood symptoms of wheezing, rhinitis, and/or eczema, and doctor-diagnosed asthma, rhinitis, and eczema, respectively, remain unclear. Objective To test hypotheses that total sum of 28 microbial volatile organic compounds (Σ26 MVOCs): 1) poses independent risk on doctor-diagnosed asthma, rhinitis, and eczema, respectively, as well as multiple symptom presentation with a minimum of the two of the above conditions (i.e. case); 2) is associated with significant interaction with absolute humidity (AH) on additive scale. Methods In a case-control investigation, 198 cases and 202 controls were examined during November 2001 – March 2002 period through home indoor air sampling, air quality inspection, and health outcome ascertainment. Results Not only the Σ28 MVOCs but also the global MVOC index were significantly higher within the homes of the cases with a high AH, compared to the controls with a low AH (all Ps < 0.001). Only the cases, but not the controls, were associated with a dose-dependent increase in the exposure variables of interest (Σ28 MVOCs) per quartile increase in AH (P < 0.0001 for the cases; P = 0.780 for the controls). Only among the children who live in a high AH homes, a natural log (ln)-unit of Σ 28 MVOCs was associated with 2.5-times greater odds of the case status (95% CI, 1.0–6.2; P = 0.046), compared to 0.7-times the odds (95% CI, 0.4–1.0; P = 0.074) of the same outcome among the low AH homes. Specifically, joint exposure to a high MVOCs and high AH was associated with 2.6-times greater odds of the doctor-diagnosed asthma status (95% CI, 0.7–8.91; P = 0.137). Conclusion Joint occurrence of high Σ28 MVOCs and AH was associated with a significant increase in the case status and asthma risks in an additive scale.

This guide is a review of the most recent European results from reports which shared experience and knowledge on how to introduce circularity in procurement documents. It also contains the authors’ own conclusions and proposes a business model and a list of possible requirements that could be introduced in procurements by municipalities.

It refers to the definition of circular building, to the principles behind it. It shows how to use the valuable experience of sustainability and how to pass from a sustainable procurement (Green public procurement) to circular procurement.

The guide is meant to be a reference, a supporting document for public decisions-makers when choosing criteria for procurement document of new constructions.

In the building sector, net-zero energy performance targets and reduction of CO2 emissions are the main drivers for building integrated photovoltaics. Recent market studies [10,18,19] show the history and perspective of the global market in the BIPV sector and calculate a global compound annual growth rate of ~ 40 % from 2009 up to 2020.

In Europe, the BIPV market is in a transition. The past decades of a slowly emerging BIPV market have been characterized by the original dominant value of BIPV: a building that communicates an image of sustainability and innovation. Payback time or "return on investment" have not been the major parameters in the decision process for applying BIPV. This is changing now. In most European countries, the new regulations on energy performance in buildings (derived from the European Energy Performance of Buildings Directive and the Directive on energy efficiency) have been translated in national regulations/laws, stating that all new (and freshly refurbished) buildings of the EU member states should be nearly zero energy buildings (nZEBs) by 2020. Thus, the time for the regulations to become mandatory is very near. It is expected that the energy performance regulations are now taking over as the main driving factor for the BIPV market and that should have huge consequences in removing the difference between a conventional building component and a BIPV component both in aesthetical and construction terms. This has led to intensified research and development aiming to create BIPV products that come in a variety of colours and sizes, while at the same time being as close as possible to existing building components, to its requirements and how it is considered by the construction industry.

The given market overview of state-of-the-art coloured BIPV products clearly reveals that for all parts of a BIPV module (glass, polymers, PV-active layers), there are technical solutions available for colouring. Pilot projects utilizing coloured BIPV products have been built in numerous (mainly European) cities clearly demonstrating the maturity of these solutions.

The key aspect that has been slowing down the progress of implementation of these aesthetically appealing and technically sophisticated new products into a wider market are the costs. In this respect, a lot of effort has been made to improve and optimize the relationship between colour and efficiency/power generation of BIPV elements. The results of the past and on-going innovative research and intensified fundamental considerations are also summarized in this report.

Besides the colour perception of the coloured BIPV elements under solar irradiation which is essential for the acceptance of the exterior appearance of a building, also transparency and inside visual comfort of BIPV – windows and façade elements are essential for the users and inhabitants.

This study examines renovation strategies among owners of rental housing in Sweden in response to European energy policies that promote deep renovation as a means to reduce carbon emissions from residential buildings. Case studies of eleven housing companies, seven public and three private, were designed with the aim to examine housing owners’ attitudes and renovation strategies, and how policies and objectives for energy efficiency become incorporated into these attitudes and strategies. Results are illustrated in typologies that distinguish between renovation strategies with either a more commercial or a more societal focus and spanning between deep and partial renovation. The typologies can be used to discuss how different aspects influence renovation, and illustrates how strategies change over time. The study identifies a trend in which housing owners are increasingly relying on partial or over-time renovation. Cost is one important driver, but social responsibility toward tenants and in some cases the protection of cultural heritage are also found to be important. A distrust of fixed models for renovation was observed. The paper questions the concept of deep renovation and suggests instead partial and over-time renovation as a way forward toward sustainable renovation. Partial renovation can bring together energy efficiency with environmental, financial, social, and cultural objectives of housing management. If managed properly, over-time renovation can reduce the risk of an investment, and has the advantage of allowing future technological advancements in energy efficiency to be included in current planning.

This work presents a numerical model to analyse the hygro-thermal behaviour of wooden bridge members. A multi-Fickian hygro-thermal model, previously implemented by some of the authors, is extended by including the dependency of wood sorption on temperature above and below zero degrees Celsius to predict moisture, temperature and relative humidity in wood under Northern European climates. The performance of the model in the presence of protective paints is particularly investigated. The finite element analysis based on the proposed model simulates the hygro-thermal behaviour of a glue-laminated beam of Älsvbacka Bridge located in Skellefteå (North of Sweden). The beam, coated by paints and claddings, was monitored by using wireless sensors in a previous research. Comparisons with the available measurements reveal that the numerical model is able to predict the moisture content in locations sheltered from rain and sun with moisture levels below the fibre saturation point. A study of the influence of different protective paints shows that the maximum and minimum moisture content at various depths along horizontal paths of the beam cross section, as well as the moisture gradients in different seasonal periods, are strongly affected by the type of paint. The proposed numerical approach is a promising tool to facilitate sensor-based monitoring techniques and to optimize the choice of protective paints for improved performance of timber bridges and other wooden structures under variable climates.

In this article, we investigate the correlation of selected physical properties with structural changes in quaternary mixed modifier alkali/alkaline earth oxide silicate glass  systems,  focusing  either  on  the  mixed  alkali  effect  [(20−x)Na2O–xK2O– 10CaO–70SiO2 (x = 0, 5, 10, 15, 20)] or on the mixed alkaline earth effect [20Na2O– (10−y)CaO–yBaO–70SiO2 (y = 0, 5, 10)]. A maximum microhardness and packing density, as well as a minimum glass transition temperature were observed for mixed alkali glasses. The mixed alkaline earth glasses do not exhibit any clear extrema in any  of  the  properties  studied.  The  hardness  and  glass  transition  temperature  de-creases, while the density and molar volume increases with increasing BaO content. Raman spectroscopy showed an increase in the Q3 group compared to the Q2 and Q4 groups as the high field strength ions Na+ or Ca2+ are substituted by their low field strength analogs K+  or Ba2+. In the mixed alkali series, the high field strength ion Na+, seems to push the low field strength ion K+ into lower energy sites when present simultaneously, while such an effect is not apparent for the mixed alkaline earth glasses, where the far IR spectra of mixed glasses are equivalent to the weighted averages of the pure glasses.

The local structures of Cu(I) and Cu(II) in (20-x)Na₂O-xK₂O-10CaO-70SiO₂ glasses with a copper content of 0.4 mol% have been investigated by Cu K-edge extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES). Complementary data for Cu(II) was derived using UV–Vis-NIR spectroscopy. Indication for mainly linear two-fold coordination of the Cu⁺ ion was found by both EXAFS and XANES, but other coordination between Cu⁺ and O^2– cannot be excluded. The Cu(I)-O bond lengths were found to be 1.79–1.83 ± 0.02 Å. EXAFS results showed that Cu(II) was mostly present in a Jahn-Teller distorted environment with oxygen, an octahedron with four shorter Cu(II)-O bonds and two longer in axial position. The equatorial bond lengths were found to be 1.89–1.91 ± 0.02 Å and the axial 2.20–2.24 ± 0.02 Å with no effect of the Jahn-Teller distortion of the octahedron when the glass composition was altered.

I vilken omfattning kan ökad återvinning av glas leda till minskad energianvändningoch minskade koldioxidutsläpp vid glasproduktion, minskad miljöpåverkan genomdeponi samt på lång sikt möjligen minskad brytning av icke-förnyelsebar naturråvara?

Solar energy is promising renewable energy where glass is an important material and have a significant impact on the efficiency of the photovoltaic (PV) module. The cover glass of PV-modules constitutes a large part of the total weight of the unit. In a recent Solar-ERA.NET project, LIMES (www.limes.nu), have we been aiming towards developing 1 mm thin glass for PV modules by improving the indentation mechanical properties and by investigating a novel thermo-chemical strengthening method.

Starting from traditional soda-lime-silicate float composition different components was studied in a DoE fashion. The mechanical properties were studied using nano- and microindentation, the chemical durability by P98 analysis and weathering experiments. The findings resulted in a suggested composition for improving the properties of float glass by adding small amounts of zinc and titanium oxide as well as increasing the amount of aluminum and magnesium oxide. The components found to improve the chemical resistance were alumina, zirconia, zinc, lanthanum and titanium oxide. The surface hardness, crack- and scratch resistance were improved when magnesia was replaced with zinc oxide. When magnesia was replaced with titania, the hardness was increased.

Some results from the thermo-chemical strengthening experiments will be presented. Heating and quenching in a reactive gas atmosphere using aluminum precursors have resulted in chemically modified surface in addition to the thermal strengthening.

Conference proceedings from the conference ICTB 2017, the 3rd International Conference on Timber Bridges, 26-29 June 2017 in Skellefteå, Sweden. Content of the conference is presented in the Conference programme included in these proceedings on pages 3-10.  Papers presented at the conference were distributed on USB to participants at the conference.

The conference contained 5 Keynote presentations and 45 Technical papers presented in 10 sessions, and also a technical visit to wooden buildings and bridges in Skellefteå.

A pre-tour included visit to several timber bridges between Skellefteå and Umeå, and the pretour programme is included in these proceedings on pages 11-15.

Protection of existing building façades – preliminary study

General concepts related to explosive loading and associated effects on buildings have been discussed. Requirements pertaining to the explosive and vehicle impact resistance of various building components were also elaborated along with the mention of relevant safety measures. Assessing the explosive resistance of existing buildings, with a focus on facades, was discussed in combination with design requirements and potential strength-ening approaches. Relevant literature covering the developments of this field was re-ferred to throughout the report.

It was suggested that a future quality assurance method be devised with the title of "By-ggaS – Method for quality assurance of safe buildings". ByggaS is a method of working with safety issues related to the entire construction process. This encompasses quality assurance requirements (phased), planning and production. With the help of quality management routines and checklists, this method ensures that quality is met in each process through continuous documenting, communicating, checking and verifying the work. Overall, ByggaS allows for an increased quality and safety of the building to be delivered. It facilitates the work of individual construction projects and provides a more efficient process by offering the project participants a complete working method with associated tools/templates.

The paper presents two illustrative examples about the utilization of structural health information for rational decision making in everyday bridge management. It is suggested that Bayesian decision analysis could be useful even in sample cases to help efficiently use specific and generic information about structural condition. However, there are some challenges concerning practical application.

In order to achieve a consistent level of failure probability, structural design codes are optimized using probabilistic methods. This optimization process traditionally focuses on the ultimate limit states (ULS). However, in the design of timber structures the performance of the structural members is often governed by the serviceability limit state (SLS) associated with different load levels than applied in the ULS. The probability of serviceability failure is strongly dependent on the loading sequence and the time-dependent response of timber; therefore, a time-variant probabilistic model is recommended to estimate them properly. This study aims to investigate the time-dependent reliability for long-term deflections of timber office and residential floor beams according to the specifications of the Eurocodes. A simple creep model is used to calculate the deflections and Monte Carlo simulation is carried out to determine the reliability index. It was found that the creep factor and the suggested deflection limits given in Eurocode 5 might not be appropriate to achieve the expected target reliabilities. To obtain a more consistent reliability, more suitable values for the mentioned parameters were suggested. However, the primary aim was to present a framework to determine appropriate deflection limits for structural codes.

In this contribution a practical and rational decision-making approach is presented to be applied for common bridges typically managed by public authorities. The authors have developed a model with the intention to be applicable for practical cases for common bridges in the daily work of bride operators responsible for a large number of assets, yet still maintain the principles of more generic frameworks based on probabilistic decision-theory. Three main attributes of the verification of sufficiency of structural performance are considered, namely: 1) the level of sophistication of modelling performance, 2) the degree of verification and acceptance criteria in terms of dealing with uncertainties and consequences, 3) the extent of information is obtained and incorporated in the verification. The simplicity of the approach is demonstrated through an illustrative case study inspired by practical condition assessment decision problems. It is argued that in practical cases it may be desirable to utilize less advanced methods owing to constraints in resources or lack of reliable data (e.g. based on structural health monitoring or other on-site measurement techniques). 

As urbanization continues and more people move into cities and urban areas, pressure on availablelandfornewconstructionswillcontinuetoincrease. Thissituationconstitutesanincentiveto reviewtheneedforinteriorspaceandusesofexistingbuildings. Agreatdealcanbegainedfromusing existingbuildingsmoreefficientlyinsteadofconstructingnewones: Reducedresourceusageduring construction(investments,naturalresources,andenergy),operation,andmaintenance;moreactivityper squaremeterofbuildingscreatesagreaterbasisforpublictransportandotherservices;moreintensive useofbuildingscreatesamorevibrantcitywithoutbuildingonvirginland. Theaimofthispaperisto initiateadiscussionregardinghowdigitalizationcanaffectthedemandandsupplyofinteriorspace in existing buildings and elaborate on how policy can support more resource-efficient uses of space. New activity-based resource measurements intended for use in buildings are proposed, and several principles that have the potential to decrease environmental impact through more efficient usage of space are outlined. Based on these ideas for encouraging the flexible use of building spaces that are facilitatedbydigitalizationandthenewmeasurementapproaches,afour-stepprincipleforconstruction isproposed: Thefirststepistoreducethedemandforspace,thesecondistointensifyusageofexisting space, the third is to reconstruct and adapt existing buildings to current needs, and the fourth is to constructnewbuildings. Urgingpolitical,municipal,construction,andreal-estatedecisionmakersto contemplatethisprinciple,particularlyinviewofthenewconditionsthatdigitalizationentails,willlead tomoresustainableconstructionand,inthelongterm,asustainablebuiltenvironment.

The construction, operation and maintenance of transportation infrastructure require energy and materials which impact the environment. Large infrastructure projects thus use resources intensively and leave a significant environmental footprint. To demonstrate and support the sustainability of such large-scale projects, life cycle assessment (LCA) has become a common tool to evaluate environmental impacts in all stages of infrastructure life cycle, from raw material production through end-of-life management. However, the various phases of the assessment are all associated with uncertainties. If decisions are made without consideration of these uncertainties, they might be misleading and suboptimal. In this paper, results are presentedwhere variations associated with different parameters and tools for life cycle assessment have been considered using probabilistic methods. A categorization of common uncertainties in LCA is also included. The most influential parameters can be identified with sensitivity analysis methods, since for LCA with a large number of parameters it may be unreasonable to incorporate all in a probabilistic simulation. For a limited amount of influential variables, Monte Carlo simulation has been used to assess the effects of uncertainties on the results.A bridge has been used as a case study to find important aspects in infrastructure LCA. The results indicate that if the most influential parameters are considered as random variables, it is possible to estimate the uncertainty and increase the validity of the life cycle assessment.