Municipal building refurbishment projects are carried out under conditions of high uncertainty and complexity, which often result in unsatisfying outcomes. In this research, a case study approach is used to provide a holistic presentation of the sources of uncertainties in the early phase of a municipal school refurbishment project in Finland. The study also explores how these sources are treated in the case project. It is considered that the uncertainty in the case study originated from three key sources: from the project due to the characteristics of existing buildings; from the organization due to the separately operating municipal units; from the municipal environment due to the municipal policy, and decision-making process. This study shows that more emphasis should be laid on the sources of uncertainty in the early phases of a municipal building refurbishment project for reaching proper decisions. In addition, the study presents suggestions for improving the municipal process.

The purpose of this study was to investigate how internal convection in loose-fill insulations affects the insulation properties of highly insulated roof structures. This study consists of laboratory measurements of roof structures insulated by two different blown-in insulations. The measurements are repeated with two temperature differences and air velocities for 300 mm and 600 mm thick insulation layers both with and without trusses, making a total of 24 case studies. The measurements were conducted with equipment using the calibrated hot-box method. The results of the tests show that internal convection can reduce insulation capacity significantly, especially with low-density loose-fill insulations, such as blown-in glass wool. A critical evaluation should be performed as to whether international standards and national building regulations take internal convection into account adequately. According to this study, 5 should be used as a critical modified Rayleigh number for horizontal roof structures with an open upper surface when used insulation material is loose-fill glass wool or wood fibre insulation as in this study.

Mobility as a Service (MaaS) is a concept that is based on the idea of providing customers with comprehensive mobility services by seamlessly combining various modes of transport. The scientific research on this theme has increased considerably over the last few years, but very little research has so far been conducted on people's willingness to pay for new MaaS services. This study presents the results of a survey (representative sample size 6,000, number of respondents 1,176, response rate 19.6%) conducted in Finland regarding people's willingness to pay for MaaS offerings. The study also estimates the current mobility costs of the respondents and relates their willingness to pay for MaaS to their mobility costs. Analysis includes also a linear regression model of willingness to pay for MaaS. As a result of the study, it was found that 43% of the respondents would be willing to adopt a mobility package, assuming it could cover all mobility needs of the respondent. For such a mobility package, the respondents were willing to pay approximately €140 on average, while their relative willingness to pay was an average of approximately 64% of their current mobility costs. However, it should be noted that due the limitations of the study, the results are mostly indicative and further research is called for to grasp the multifaceted qualitative elements related to willingness to pay for MaaS. This study shows some significant variation between user groups in the respondents’ willingness to pay relative to their estimated mobility costs, as well as their absolute willingness to pay. The variation maybe due to the fact that MaaS is still largely unknown as a concept and the challenge that the mobility package which fulfils individual needs differs from person to person. According to the results, MaaS should lower the mobility costs for users in order to be financially attractive.

Receiving the qualitative, energy efficient and economic building is the main tendency in the civil engineering. One of the leading places is occupied by technology of frame-panel construction with use of new non-autoclaved, monolithic foamed concrete technology producing on a building site. On the example of the real samples there were determined the heat-shielding properties of foamed concrete in a condition of setting process and after attainment of strength with a practical and theoretical methods. The results were obtained for a non-autoclaved monolithic foamed concrete wall fragment (lightweight steel concrete structure - LSCS) for the areas with and without rigid reinforcement with steel thin-wall profiles (lightweight gauge steel structure - LGSS). Influence of the thermal bypass on cold-resisting properties of enclosure structures with technology "Intech LB" is revealed. On the basis of the received results, modernization of a design for improvement of its thermotechnical characteristics is made.

A mixed-mineralogy talc mine tailing (MT) fraction consisting of 80% ferroan magnesite (MgCO₃) was studied for utilization as the source of magnesium oxide (MgO) in magnesium potassium phosphate cement (MKPC). The effects of calcination temperature of this low-grade magnesite on the composition, BET surface area and phosphate reactivity of the resulting magnesia powder were studied. The 4-point flexural strength of resulting MKPC was measured for all calcined raw material fractions that produced a solid. Based on the strength measurement results, the optimal range for calcination resided between 700 °C and 1150 °C, which is drastically lower than commonly recommended for finer magnesia sources in MKPCs. Accelerated reactivity assessment showed that phosphate reactivity behavior could not be entirely predicted by BET surface area. The presence of impurity silicates and high iron content in all the constituent minerals was posed as the reason for densification and loss of reactivity at higher calcination temperatures.

Green facades are one of the most promising natural-based solutions for buildings. Notwithstanding, in regions with variating weather such as the northern hemisphere, these can be counterproductive for the structures due to humidity retention. For these reasons, this work presents the development of an Artificial Neural Network (ANN) model to estimate the hygrothermal behavior inside a concrete wall protected by a second foliage skin. The database used for model formation was obtained through measurements made in an Accelerated Weathering Laboratory (AWL) to emulate the Nordic climatic conditions for a typical year. The ANN-hygrothermal model was trained in function of the parameters: environment relative humidity, ambient temperature, microclimate's relative humidity, microclimate's temperature, and the separation distance between the vegetation and the wall. The statistical results of the model demonstrated successful adaptability and great generalization capacity for both internal temperature (R² = 99.98% for training and R² = 99.95% for testing) and internal humidity (R² = 99.16% for training and R² = 99.17% for testing). Additionally, a sensitivity analysis was implemented, showing that the most influential variable in the estimation of both hygrothermal parameters is the ambient temperature and that the separation distance has a significant impact on the humidity produced inside the wall. Finally, the presented computational approach can be implemented in non-invasive monitoring systems or as a complementary tool in studies of concrete degradation due to humidity.

This paper deals with the valorization of quartz and felspar rich lithium mine tailings (QFS) in the development of construction materials. Ladle slag was used as green strength increasing agent. Sodium hydroxide and carbonate were used as fluxing agents to allow sintering at 700–900 °C. Of these, sodium hydroxide was found to be the more efficient. The sintered ceramics were characterized by X-ray diffraction, scanning electron microscopy, compressive test, water absorption, apparent density and dilatometry; the results were found to comply with ASTM C62-99 specifications for building brick, and interesting for a sustainable use of resources.

The determination of a design soil property may include multiple sources of uncertainty. One of the sources originates from transformation model used to evaluate soil parameters when they are not measured directly. This study focuses on the transformation uncertainty related to three different transformation models used in evaluation of undrained shear strength from CPTu borings. The used correlation models are common models found in literature and calibrated at Tampere University. The CPTu data used in this study was taken from Knuuti and Länsivaara [2019. Variation of Measured CPTu Data. ISGSR], and it consisted of four different soft clay sites in Finland. The transformation uncertainty was calculated for each transformation model at each site. Moreover, every CPTu boring was analysed separately. The results showed that the transformation uncertainty was lowest for models based on the net cone resistance (COV = 0.033–0.084) and pore pressure (COV = 0.024–0.085). For the third model, the uncertainty was little higher as it included more uncertainty in the initial parameters. This suggests that the transformation models based on net cone resistanse (q_NET) and pore pressure (u₂) could be more suitable for practice.

The resistance of a steel joint is one of the most crucial elements of a structure under fire conditions. The aim of the study was to investigate the temperature distribution within the square hollow section (SHS) joints with different geometric parameters under fire conditions. The commercial finite element (FE) software, Abaqus/Standard CAE, was used to simulate the behaviour of the SHS joints. Extensive numerical research was conducted on different joint types (T-, Y-, and K-joints) to examine the influence of the joint configuration on the temperature distribution within the joint. To provide reliable observations, a model was validated against the experimental results. The FE simulation results were compared to the predictions of Eurocode equations. The FE simulation results showed that the simulated temperatures are different from the temperatures determined using the Eurocode method. The β parameter was found to have hardly any influence on the temperature distribution within the joint area, whereas different joint configurations strongly influence the distribution.

Climate change is expected to increase the frequency and duration of hot weather and its associated adverse health effects. In dense urban areas, these phenomena will be exacerbated by the Urban Heat Island (UHI) effect and indoor overheating. This paper assesses population exposure and vulnerability to high summer temperatures by exploring the geospatial connection between the UHI, housing energy efficiency and overheating risk, and social vulnerability indicators, such as income and the elderly population. Focusing on Madrid and London, two European cities with strong UHIs but contrasting drivers of indoor heat risk, the spatial distribution of selected indicators were analysed by means of Geographical Information Systems, and areas with the highest vulnerability towards summer energy poverty were identified. It was found that while ‘hot and vulnerable’ areas are present in both Madrid and London, there are significant differences in climate, socioeconomic distribution and housing between the two cities. In warmer climates such as Madrid, energy poverty—traditionally defined by wintertime heating—requires its definition to be broadened to include summertime cooling needs; in the context of climate change and urban warming trends, this may soon also be the case in northern cities such as London.

Recently, CIDECT (International Committee for the Development and Study of Tubular Structures) has proposed the component method as a unified approach for the design of many types of connections, including welded tubular joints. Although CIDECT provides clear and simple equations for the resistance of welded tubular joints, the design of initial stiffness remains complicated and includes a number of uncertainties. This paper analyzes the theoretical approach for the initial axial stiffness of rectangular hollow section T joints. The validation against experimental data has shown that the component method considerably overestimates the stiffness of T joints. The paper develops new equations for the stiffness of the components “chord face in bending” and “chord side walls in compression”. The equations are based on simplified mechanical models, employing finite element analyses to calculate the parameters for which analytical solutions are found extremely complicated. In addition, the article numerically investigates the effect of chord axial stresses on the axial stiffness of joints and proposes a corresponding chord stress function.

Traditionally, the emissions embodied in construction materials have not been considered important; however, they are becoming crucial due to the short time-frame in which the emissions should be reduced. Moreover, evaluating the environmental burden of construction materials has proven problematic and the reliability of the reported impact estimates is questionable. More reliable information from the construction sector is thus urgently needed to back and guide decision-making. Currently, the building sector environmental impact assessments predominantly employ commercial software with environmental impact databases and report results without knowledge about the impact of the software/database choice on the results. In this study, estimates for the embodied environmental impacts of residential construction from the two most widely used life cycle assessment (LCA) database-software combinations, ecoinvent with SimaPro software and GaBi, are compared to recognize the uniformities and inconsistencies. The impacts caused by two residential buildings of different types, a concrete-element multi-story residential building and a detached wooden house, both located in Finland, were assessed, including all building systems with a high level of detail. Based on the ReCiPe Midpoint method, fifteen impact categories were estimated and compared. The results confirm that the tool choice significantly affects the outcome. For the whole building, the difference is significant, around 15%, even in the most widely assessed category of Climate Change, and yields results that lean in different directions for the two cases. In the others, the estimates are entirely different, 40% or more in the majority of the categories and up to several thousand percentages of difference. The main conclusion is that extensive work is still urgently needed to improve the reliability of LCA tools in the building sector in order to provide reliable and trustworthy information for policy-making.

Historical dwellings make up a significant fraction of the French building stock and require substantial retrofitting to reduce their energy consumption and improve their thermal comfort. In the city center of Cahors, France, the old medieval dwellings are considered as valuable cultural heritage and internal insulation is often the only insulation technique that can be used when the architectural value of the exterior façade is to be preserved. However, internal insulation may have an impact upon the hygrothermal performance of the wall, leading to lowered drying capacity, with possible interstitial condensation and mold growth. Hygrothermal models may be used to assess the risk of failure, but the accuracy of the results depends on how reliable the input data is, including external boundary conditions, which may vary significantly in dense medieval cities such as Cahors. In this study, a Geographical Information System model of Cahors is used to develop EnergyPlus models of individual dwellings. The boundary conditions output by these models are, in turn, used to model the hygrothermal performance of façades with different internal insulations, using the hygrothermal tool Delphin. The Delphin outputs are then analyzed with the VTT model, a mold growth assessment model. Results highlight a quantitative correlation between some urban morphology characteristics and the hygrothermal performance of refurbished walls, with some configurations raising the risk of damage patterns. We find that bio-based insulation presents a better hygrothermal performance than mineral wool in most of the configurations.

It is a well-known fact that the so-called stressed skin design results in ca. 10-20 % mass and cost savings in a typical steel hall structures. The potential of this design method is however, too often disregarded due to e.g. rather complex and limited existing design rules and instructions. In this paper, a method for determination of generalized elastic parameters is proposed, so that the stressed skin can be modelled in the general finite element software using existing elements and material parameters. With the proposed method, structural designer can take advantage of the stressed skin design in the context of basic design tools as Autodesk Robot or RFEM.

For years, scientists have been looking for different techniques to make glasses perfect: fully amorphous and ideally homogeneous. Meanwhile, recent advances in the development of particle-containing glasses (PCG), defined in this paper as glass-ceramics, glasses doped with metallic nanoparticles, and phase-separated glasses show that these "imperfect" glasses can result in better optical materials if particles of desired chemistry, size, and shape are present in the glass. It has been shown that PCGs can be used for the fabrication of nanostructured fibers-a novel class of media for fiber optics. These unique optical fibers are able to outperform their traditional glass counterparts in terms of available emission spectral range, quantum effciency, non-linear properties, fabricated sensors sensitivity, and other parameters. Being rather special, nanostructured fibers require new, unconventional solutions on the materials used, fabrication, and characterization techniques, limiting the use of these novel materials. This work overviews practical aspects and progress in the fabrication and characterization methods of the particle-containing glasses with particular attention to nanostructured fibers made of these materials. A review of the recent achievements shows that current technologies allow producing high-optical quality PCG-fibers of different types, and the unique optical properties of these nanostructured fibers make them prospective for applications in lasers, optical communications, medicine, lighting, and other areas of science and industry.

The ITER Remote Handling Control System (RHCS) controllers provide measurement and diagnostics data about the remote handling equipment and tools they control. This paper presents the Remote Diagnostics Application (RDA) software for the analysis and archiving of the RHCS diagnostics data. The RDA provides a basic set of diagnostics tools, including trends, spectra, histograms, scatter plots, cross-correlation plots, as well as archiving and retrieval of history data. The ITER RH operators can extend diagnostics capabilities for specific RH equipment needs by incorporating custom diagnostics functions. To facilitate customization, RDA implements an architecture with three nested levels: the RDA Framework, its Diagnostics Workbenches and their Diagnostics Primitives. The RDA Framework has a user interface that can load one or several special diagnostics cases implemented as custom Diagnostics Workbenches with custom or default Diagnostics Primitives, such as rules, analysis functions and filters. As a result, the RDA features a diagnostics framework to execute complex and dedicated diagnostics and prognostics for the RH experts to monitor performance data, to run diagnostics tests and rules on equipment systems and to analyse historical data. The RDA helps the RH operators reduce downtime of the Remote Handling systems by exposing failure conditions and maintenance needs.

Based on recent studies, high strength steels (HSS) can be efficiently used in civil engineering, reducing the consumption of material and CO₂ emissions. The present Eurocode contains the reduction coefficients (0.8 and 0.9 depending on the steel grade) for high strength steel joints. These reduction factors lead to the excessive consumption of material, making the usage of HSS for construction not as economically viable as it might be. The scope of this paper is to present experimental results dealing with the welded in-plane moment-loaded HSS joints. Twenty tests on square hollow section T joints were performed to observe their moment-rotation relationship, studying the following parameters: (1) bending resistance, (2) rotational stiffness, (3) ductility. The results show that the reduction factors are needed only for butt-welded joints, as well as for joints with small fillet welds and made of steel grades higher than S500. The required ductility was achieved by all specimens, even when using welds smaller than full-strength fillet welds. In addition, it was shown experimentally that fillet welds considerably increase the resistance and stiffness of joints.

New energy efficient windows have a higher risk for outdoor air vapour condensing to their exterior surface, when compared to older windows with lower thermal resistance. This external condensation can reduce visibility through the window, decrease owner satisfaction and affect the behaviour of window buyers and sellers. The purpose of this study was to analyse the impact of window U-value and other factors on the occurrence of external condensation. A combined heat and moisture transfer model was created and used for the calculations. According to the results, the duration and amount of external condensation are projected to increase in the future due to lower window U-values and climate change. Exterior surface emissivity, external shadings and building location had a big impact on the amount of yearly condensation hours, while window orientation and solar absorption coefficient had a smaller impact. There was also an interesting power-law-type correlation between yearly condensation hours and the median effective thickness of the condensation layer. The results help window manufacturers and building designers make more accurate decisions in their future work.

In this case study was to investigate how ventilation of the crawl space will influence on concentrations of radon, fungal spores and MVOCs in the crawl space and indoors of detached house. The crawl space pressurisation by exhaust air from indoors was successful to prevent the convective flow of radon from the soil, but it increased microbial growth in the crawl space. After installation of the supply and exhaust ventilation in the crawl-space and in the living space, the concentrations of fungal spores in the crawl space and also entry of radon and MVOCs into a house decreased. A microbiologically safe crawl space was determined with hygrothermal simulation utilizing the Finnish Mould Growth Model and a two year examination period. The optional structures of the crawl space being depressurised with exhaust ventilation included an open base uncovered ground and various air-sealed closed structures. When mould growth of building materials was at medium resistant sensitivity class, mould was not observed during different air change rates in any of the examined structures. Open base uncovered gravel ground is a functional solution of a crawl space, only when there are no organic materials. The air-sealed ground structure is recommended build with concrete + insulation and when air exchange rate (ach) varied from 0.2 to 1 h⁻¹. A concrete ground in the crawl space having ach from 0.2 to 0.6 h⁻¹ is also very effective. XPS insulation and plastic sheet covered ground are not recommendable due to their high mould index.

Alstonia congensis (Ahun) and Ceiba pentandra (Araba) were chosen as representations of tropical wood in this study. The use of untreated wood for energy recovery could lead to a high loss in efficiency. One way of circumventing this in a developing country such as Nigeria is by exposing the fuel materials to a pre-treatment, such as torrefaction, prior to deployment. Attempts were made to improve the combustion properties of these resources and also to investigate their torrefaction kinetics. Derivations of kinetic parameters using Coats-Redfern method were discontinued due to inconsistent results. A non-linear regression method was then employed and the results compared to the average value obtained by the FWO method, which was considered more viable than the Coats-Redfern method. The kinetic parameters (E_a,A and n) derived by the regression method are 134.45 kJ/mol, 1.83E+13 min⁻¹ and 2.15, respectively, for Araba and 143.38 kJ/mol, 1.90E+10 min⁻¹ and 2.28, respectively, for Ahun. The thermal behaviour of the samples showed that a lower mass yield resulted in a lower energy yield, while the heating values increased with the temperature of torrefaction. The results obtained in this study affirm the possibility of obtaining an optimum conversion of these resources for energy recovery.

ICT advances have enabled the incorporation of multiple devices that monitor various aspects of the environment into building management (BM) systems. The data from these devices is used to detect multiple abnormal situations, which require the awareness of system users and/or timely response. However, the number of abnormal situations is usually large, and delivering all of the associated notifications is overwhelming for users, rather than helping them to interpret the ongoing status of the environment. This work proposes a novel approach for combining ongoing notifications in the monitoring systems by their types, priorities, locations, and receivers. The approach is based on formal classification of possible alarms and runtime analysis of ongoing notifications with the aim of reducing repeating information pieces delivered as part of multiple notifications. The paper provides details of combination principles of notifications and applies them to real data from a rehabilitation facility. The results show a reduction in the users' information load of approximately 42% of the peak number of ongoing notifications. It is expected that the proposed approach will improve situation awareness in the managed facilities – enabling better and faster decisions on the ongoing status of the environment.

Experimental determination of elastic constants of anisotropic composite laminates in all orthogonal directions is generally a complex process. In this paper a simple direct technique to determine a broad set of elastic moduli is presented based on compression testing of a prism sample. Digital image correlation is used to measure the full-field deformations that allow the determination of Young's moduli and all six Poisson's ratios for the three orthogonal directions based on a single sample. Finite element model is used in evaluation of the effect of friction on the measured properties. In addition to quantitative characterization of the material properties, local strain mapping is used in qualitative evaluation of the sample structures.

Generally, numerical simulations of structures are carried out in such a way as to most accurately repeat their real behavior. The current rules for finite element modeling of tubular joints oblige scientists and engineers to construct their numerical models considering initial imperfections. However, not all joints are sensitive to initial imperfections. Often consideration of initial imperfections brings no reasonable improvements in the accuracy of results, but severely complicates numerical simulations. In such cases, the effect of geometrical imperfections can be effectively replaced by a simple theoretical equation or neglected entirely. This paper evaluates the effect of initial geometrical imperfections on the structural behavior of cold-formed rectangular hollow section T joints. Imperfections are simulated using the conventional approach for thin-walled structures, applying corresponding buckling modes to the perfect geometry. The paper analyzes several buckling modes and their combinations to identify the most rational technique for simulation of imperfections under in-plane bending and axial loading. Based on the obtained results, parametric studies are conducted to investigate the effect of initial imperfections on joints with various geometry and material properties. The results demonstrate that initial imperfections reduce the resistance and initial stiffness of joints. However, the observed effect has been found sufficiently small to be safely ignored in computational analyses.

In recent days, the interest on torrefaction is increasing owing to its ability to improve biomass properties to a level of competing with coal. However, its techno-economic feasibility still need to be optimized. Integrating torrefaction with other thermochemical and biochemical processes could be a feasible option to improve the performance of the torrefaction process. In that regard, this study evaluates the techno-economic feasibility of integrating the torrefaction with anaerobic digestion (AD). In addition, new process configurations were studied to identify the possible heat energy recovery options. Technical feasibility was tested through mass and energy balance at each process unit. The economic indicators such as net present value (€), minimum selling price and internal rate on return (%) were used to evaluate the economic performance. At 10 t/h of torrefied biomass pellets production capacity, the estimated bio-methane production from AD was 369 m³/h. The economic evaluation shows that the minimum selling price of the torrefied biomass to reach the breakeven could be reduced from 199 €/t for standalone torrefaction to 185 €/t in case of torrefaction integrated with AD. The sensitivity analysis shows that feedstock and total capital investment were the most sensitive input parameters. This study shows that integrating the torrefaction with AD has better technical and economic feasibility than standalone torrefaction.

Purpose – The manufacturers of construction components and materials are the suppliers in construction projects, and represent a significant portion of their value. However, their knowledge is not used sufficiently when it comes to construction innovation. This research paper focuses on the suppliers' innovation potential in construction projects. The purpose of this paper is to identify practices for enhancing the contractor-supplier relationship and using the suppliers' innovation potential in construction projects. Design/methodology/approach – A qualitative exploratory research strategy is used in the context of construction projects. In total, 18 interviews were conducted with contractors to discover the experiences and practices related to the contractor-supplier relationship and construction innovation. Findings – The contractors perceive that the suppliers have innovation potential, and that they are often a source of construction innovation. The findings reveal business- and project-level practices for enhancing the contractor-supplier relationship and for overcoming barriers that hinder the suppliers' innovation potential. Research limitations/implications – The research conducted for this paper is limited to the contractors' perspectives based on construction projects in one country. Further research is encouraged to verify the success of identified practices and cover the perspectives of the suppliers, clients and designers. Originality/value – Limited research and attention is directed toward the role of the suppliers in projects within the construction industry. This paper offers important information about the part that both the suppliers and the contractors play in construction innovation and its facilitation.

In the frame analysis, the local analysis model of the joint must follow the behavior of the joint. When completing the elastic global analysis, the initial rotational stiffness of the joints should be known to obtain the reliable moment distribution between the members of the frame. This paper evaluates the existing calculation approach for the initial rotational stiffness of welded rectangular hollow section T joints. Validation with the experiments shows that the current calculation approach significantly underestimates their initial rotational stiffness. Based on the existing experimental data, the paper proposes the improvement for determining the initial stiffness. The second part of the article investigates the effect of the axial force in the main member on the initial rotational stiffness of the joint. The conducted numerical study on square hollow section T joints shows that the reduction of their initial stiffness can reach 50%, when the main member experiences the normal stresses close to yielding. Using the curve fitting approach, the paper proposes and validates a corresponding chord stress function, similar to the existing ones for the moment resistance.

The effect of steel grade on the weight and cost of Warren-type welded tubular roof trusses was investigated. For an unbiased comparison, best truss designs were obtained through optimisation. The steel strength investigated ranged from S355 to S960. Costs were calculated based on the features of the trusses. The starting point was the exact geometry of the truss, from which a finite-element model was derived. This approach allowed the resistance and other requirements of design standards of both members and joints to be included as constraints in the optimisation problem. The design variables were the truss height, the locations of joints, the gap width at the joints and the member sections, from a catalogue of cold-formed square tubes. Eurocode 3 requirements were applied. The results of the comparison imply a significant saving in weight when using high-strength steel (HSS), by as much as 50% for S960. The cost reduction was smaller, but still about 20%, for a hybrid solution of S700/S355 for the higher of two investigated load values. It is hoped the results will motivate the use and further investigations of HSSs in building products.

This study examines the relationship among civil engineering students' approaches to learning, their perceptions of the teaching-learning environment, and their study success. The aim was to identify civil engineering students' approaches to learning and how their approaches to learning are related to their perceptions of the learning-teaching environment and their study success. The data of the study consist of the students' answers to a questionnaire (n=215) and their study success data (n=204), which were gathered from their university's study register. The study success data consist of the cumulative study credits and weighted averages of their course grades. The students were classified into four clusters according to their approaches to learning. Differences in their perceptions of the teaching-learning environment and study success between the clusters were statistically significant. Students who belonged to clusters that emphasized the deep approach to learning experienced their teaching-learning environment more positively than did other students. Students who belonged to clusters emphasizing organized studying earned more credits and higher marks in their studies than did other students.

In this paper, an optimization method for a redundant serial robotic manipulator's structure is proposed in order to improve their performance. Optimization was considered in terms of kinematics using the proposed objective function and the non-linear Levenberg-Marquardt algorithm for multi-variate optimization. Range limits of the joints, bounds of the design parameters, and a constrained workspace are enforced in the proposed method. A desired manipulator can be optimized to cover the required task points using dimensional synthesis. This approach effectively optimizes the link lengths of the manipulator and minimizes the position and orientation errors of the tool center point. A commercial heavy-duty hydraulic, underground tunneling manipulator was used to demonstrate the capability of the proposed optimization method. The obtained results encourage the use of the proposed optimization method in automated construction applications, such as underground tunneling, where the confined environment and the required task add challenges in the design of task-based robotic manipulators.

This research determined the carbon dioxide permeabilities of different materials and cellulose-insulated wall structures without a vapour barrier as well as the CO₂ balance of bedroom air. Material tests have indicated that the CO₂ permeabilities of building materials correlate closely with their water vapour permeabilities. Thus, the more permeable the external wall structures are, the bigger their impact on the CO₂ content of indoor air. Yet, higher permeability allows more water vapour to pass through the structures, which make them more at-risk for condensation and mould growth. Some calculations on the CO₂ balance of bedroom air were also made which indicated that the need of ventilation is not reduced by the use of gas permeable structures.

In this research, glass fibre reinforced composite laminate samples were manufactured with filament winding technique using four different vinyl ester resin systems to study ageing. The manufactured laminate samples were conditioned in an environmental cabinet (70°C, 95 RH%), water immersion (95°C), and in sulphuric acid solution immersion under pressure (5% H₂SO₄, 95°C, 15bar). After 6 and 12months of conditioning, the samples were tensile tested and the results were compared with the initial values. Regardless of the matrix type, conditioning in the environmental cabinet resulted in the lowest weight gain and least decrease in tensile properties: the decrease in the tensile strength values was 10-25% after 12months' conditioning depending on the vinyl ester used. The water immersion was more detrimental to the samples than the 5% H₂SO₄ immersion causing the highest weight gain and the greatest decrease in tensile strength (up to 65%). However, when comparing the tensile performance, it was noted that the highest weight gain did not inevitably correlate with the strongest ageing effect. In water immersion, the ultimate strength deteriorates faster than the proof stress level leading to a decreasing damage tolerance of the vinyl-ester composite laminates.

The potential for cost-effective energy efficiency improvements is very large. However, major impacts from energy efficiency improvements can take decades to be fully realised. In addition, today the building sector is requested to define strategies and decide which energy retrofit actions to undertake in their existing building stock. Since building users are very often encouraged to save energy based on measured energy consumption, it is essential to know that the indicator used to assess energy efficiency is really guiding the building use towards sustainability. This study examines how energy measures reflect energy efficiency indicators and how they can be combined so that the result is user-driven and reflects the reality of the building operational phase energy efficiency better. This study shows that energy efficiency can be measured by using alternative indicators and confirms that different indicators make a different impact on results showing efficiency. In the studied cases savings in energy consumption can be achieved by investing in technical measures or operating the building automation system based on actual occupancy. Results indicated that the size of the effect of energy measures is roughly similar in a case of alternative indicators of energy efficiency.

This paper presents a study of the output power variation of different photovoltaic (PV) array configurations during irradiance transitions caused by moving clouds. The study was based on velocity and other characteristics of roughly 27,000 irradiance transitions identified in measured irradiance data and conducted using a mathematical model of irradiance transitions and an experimentally verified simulation model of a PV module. The studied electrical PV array configurations were series-parallel, total-cross-tied and multi-string. The different PV array orientations and layouts (physical shapes) of the configurations were also studied. The average rate of change of the power of these studied PV array configurations during the irradiance transitions was around 3%/s and the maximum instantaneous rates of change of the power were around 75%/s. Half of the time during the studied transitions, the rate of change in the power was over 1.2%/s, and most of the time during the transitions, it exceeded typical PV power ramp rate limits set by grid operators. The average rate of change of PV array power decreased with an increasing maximum array dimension and it was observed to be the largest when the shorter dimension of the array was parallel to the dominant movement direction of the shadow edges. The results of this study are relevant especially in terms of PV array design, maximum power point tracking algorithm development and energy storage systems sizing.

Monitoring and modelling studies of the indoor environment indicate that there are often discrepancies between simulation results and measurements. The availability of large monitoring datasets of domestic buildings allows for more rigorous validation of the performance of building simulation models derived from limited building information, backed by statistical significance tests and goodness-of-fit metrics. These datasets also offer the opportunity to test modelling assumptions. This paper investigates the performance of domestic housing models using EnergyPlus software to predict maximum daily indoor temperatures over the summer of 2011. Monitored maximum daily indoor temperatures from the English Housing Survey’s (EHS) Energy Follow-Up Survey (EFUS) for 823 nationally representative dwellings are compared against predictions made by EnergyPlus simulations. Due to lack of information on the characteristics of individual dwellings, the models struggle to predict maximum temperatures in individual dwellings and performance was worse on days when the outdoor maximum temperatures were high. This research indicates that unknown factors such as building characteristics, occupant behaviour and local environment makes the validation of models for individual dwellings a challenging task. The models did, however, provide an improved estimate of temperature exposure when aggregated over dwellings within a particular region.

Outdoor concrete structures such as concrete facade panels and balcony frame panels are subjected to various environmental actions causing reinforcement corrosion problems. Long-term field measurement data on reinforcement corrosion in carbonated concrete on these structures was utilized in the creation of a corrosion rate regression model combining weather parameters such as temperature, relative humidity, wind-driven rain and solar radiation to corrosion rate. A versatile model capable of predicting the effect of varying environmental actions on the corrosion rates of carbonation induced corrosion was produced. Wind-driven rain was found to have the greatest impact on corrosion rate in tandem with the micro climate surrounding the building. Due to changes in air temperature, air relative humidity as well as in the amount of wind-driven rain and solar radiation, the corrosion rate on concrete facades and balconies is constantly changing. Despite the high seasonal and yearly variation, the average level of the modelled corrosion rate was quite steady on a longer 30-year perspective. This information is substantial for the long term service life design of concrete structures.

Purpose - In a construction project, "participants' satisfaction" is one of the main dimensions used for measuring the successfulness of a project. Designers perform a major role in attaining the project goals and managing project complexity during production. The purpose of this paper is to examine the designers' performance as evaluated by the main participants: the client, the project consultant/manager and the main contractor, and to identify the main success factors of designer performance using the participants' evaluation. The study also aims to examine how the economic size of a project affects the project participants' assessment of the designer's performance. It is assumed that as the size of a project increases, so does the complexity of the project, which will affect the scope of work and demands on the designers' operational performance for the specific project level. Design/methodology/approach - The Finnish project evaluation and benchmark database was used in this study as empirical data. The quantitative data consists of surveys on the project level and are based on a multi-dimensional standard evaluation wherein the main participants evaluate each other's performances. The client, project consultant and main contractor evaluated the designer's performance. The data of the study consisted of a total of 892 evaluations. ANOVA analysis was used to examine the differences between the project participants' assessments based upon the different economic sizes of the projects. Findings - Contractors were satisfied with the designers' performance in small projects, whereas the client and the project consultant/manager rated the designers' performance most successful in large projects. This result may be due to small projects are typically simple and less complex, in which case design solutions are generally well-defined. Nonetheless, the participants' level of satisfaction follows the same factors. The main problems in the designers' performance were related to the design content: the flawlessness and comprehensiveness, as well as the compatibility and consistency of designs. These factors were emphasized particularly in the client's low satisfaction of the designer's performance. However, project participants were satisfied with the collaboration with designers; however, room for improvement could be found in internal communication and collaboration within the design teams. The findings illustrated that the assessment of the success rate of a project was party-specific, which was clearly affected by the size of the project, as large projects appeared to be more complex than smaller ones. Practical implications - The findings suggested that there is a need to develop project-specific practices in managing multidisciplinary design teams. Additionally, particularly in large projects, designers should focus more on solving problems and design requirements occurring at the construction site. However, this should be implemented in such a way that this does not interfere with the design activities conducted with the client and project management. While client satisfaction is low in the small projects, designers should focus more on customer-oriented methods to serve client needs better. Originality/value - In construction project management studies, there is a need to measure the importance that various participants assign to different success factors. Since project success factors depend on project type, a more project-specific approach is suggested to identify the main parameters for measuring project success. This study provides a holistic approach of the designers' performance, which contributes to the theory of project success and designers' performance improvement.

The work behind this paper took place in the Eurofusion remote maintenance system project (WPRM) for the EU Demonstration Fusion Power Reactor (DEMO). Following ITER, the aim of DEMO is to demonstrate the capability of generating several hundreds of MW of net electricity by 2050. The main objective of this paper was the study of the most efficient design of the maintenance port for replacing the divertor cassettes in a Remote Handling (RH) point of view. In DEMO overall design, one important consideration is the availability and short down time operations. The inclination of the divertor port has a very important impact on all the RH tasks such as the design of the divertor mover, the divertor locking systems and the end effectors. The current reference scenario of the EU DEMO foresees a 45° inclined port for the remote maintenance (RM) of the divertor in the lower part of the reactor. Nevertheless, in the optic of the systems engineering (SE) approach, in early concept design phase, all possible configurations shall be taken into account. Even the solutions which seem not feasible at all need to be investigated, because they could lead to new and innovative engineering proposals. The different solutions were compared using an approach based on the Analytic Hierarchy Process (AHP). The technique is a multi-criteria decision making approach in which the factors that are important in making a decision are arranged in a hierarchic structure. The results of these studies show how the application of the AHP improved and focused the selection on the concept which is closer to the requirements arose from technical meetings with the experts of the RH field.

The building sector contributes up to 30% of global annual greenhouse gas emissions and consumes up to 40% of all energy. Failure to encourage energy-efficiency and low-carbon in new builds or retrofitting will lock countries into the disadvantages of poor performing buildings for decades. The journey towards low-carbon and energy efficient buildings starts with good design, commissioning and measuring. The share of energy costs can be up to 50% of all maintenance costs [7] in Finland. In the studied buildings the average costs were 39% for daycare centres and 45% for schools. Since the share of energy costs is remarkable in maintenance, it is important to find out the most concrete indicators to measure energy efficiency in practice. This study explores ways in which building usage and occupancy influences the energy cost in Finnish daycare centres and school buildings. This study shows that energy costs vary a lot between different energy efficiency indicators, i.e. there is great variation in energy costs regardless of the building age and when child or student density varies. Results indicated that actual use of space is profiled in the operational phase where the energy costs variation is remarkable.

This study is focused on the energy saving and indoor climate analysis of the renovation of a 1930's brick-walled building in the moderately cold climatic conditions of Malmö in southern Sweden. Three facades of the building were glassed in and the ventilation system was renewed. The purpose of this study was to investigate the effect the added glazing would have on the building's energy demand and indoor climate. Measurements were taken on site and were used as the input for computational studies performed with the help of IDA Indoor Climate and Energy software (IDA-ICE). The study showed that the heating energy demand was reduced after the glazing installation by between 5.6% and 25.3%. In addition, the mean annual temperature difference between the cavity space and the outside air was from 5.2 °C to 11.4 °C higher, depending on the design. A number of different design options were explored for the winter and also summer case-studies, as it was apparent that adding glazing decreased the level of comfort in the building's indoor environment in summer time. This problem could be solved by increasing the cavity air flow or adding new solar shading to the front or back of the glazing.

Heat soak testing of tempered glass is a thermal process required after the tempering process itself to bring glasses of commercial soda-lime-silica-glass to failure that are contaminated with nickel sulphide inclusions, diameter 50 mm to 500 mm typically. Thus, the tests avoid a so-called "spontaneous" breakage of the glass in building elements at ambient temperatures months or years later. According to industry standards, the duration of the tests typically differs between 1 h and 4 h at temperatures of 290 ± 10 °C. Although this temperature is well below the transformation temperature of commercial soda-lime-silica glass, it causes stress relaxation in tempered glass and the fracture pattern of the glass changes accordingly, especially thin glasses are affected. Based on the Tool-Narayanaswamy-Model, this paper comprises the theoretical background of the stress-relaxation-process and the results of a parameter study for its most influential technical parameters. Results are compared to photoelastic measurements of temper stresses and fracture patterns of tempered glass before and after a heat treatment similar to heat soak testing.

Understanding the influence of hydrostatic pressure and loading rate on the strength and fracture behavior of rocks is very important for the development of deep drilling technology. This paper presents a systematic study on the mechanical properties and behavior of Kuru Gray granite at confining pressures up to 225 MPa and at strain rates of 10^-6 s^-1 and 600 s^-1. The low strain rate compression tests were carried out with a servo-controlled hydraulic testing machine with a radial confining chamber, and the dynamic tests with a special split Hopkinson pressure bar device with axial and radial confining pressure chambers. The results show that the rock strength increases significantly with strain rate and confining pressure. At confinements below 20 MPa, the strength of the material increases faster at the higher strain rate, but at confinements higher than this, the effect of confining pressure is stronger at the lower strain rate. The strain rate sensitivity increases when even a small confining pressure is applied. However, the rate sensitivity remains rather constant when the confining pressure is increased above 10 MPa. The parameters of the Hoek-Brown model and an alternative power-law model were calibrated for low and high rate data. Also, the fracture behavior of the rock was found to be strongly dependent on strain rate and confining pressure. At the low strain rate, the samples fail by axial splitting in the unconfined tests, whereas the dynamic unconfined tests result in a complete pulverization of the samples. At high confining pressures the fracture behavior is shear fracture for both studied strain rates.