Buildings

22 pages, 3973 KiB

Open AccessArticle

High-Performance Self-Compacting Concrete with Recycled Aggregates from the Precast Industry: Durability Assessment

by Tiago Barroqueiro, Pedro R. da Silva and Jorge de Brito

Buildings 2020, 10(6), 113; https://doi.org/10.3390/buildings10060113 - 26 Jun 2020

Cited by 19 | Viewed by 3765

The main objective of this paper is to provide the industry with a simple and practical way of disposing and recovering recycled waste from precast reinforced concrete elements rejected during the quality control process, while minimizing the consumption of natural resources in the [...] Read more.

The main objective of this paper is to provide the industry with a simple and practical way of disposing and recovering recycled waste from precast reinforced concrete elements rejected during the quality control process, while minimizing the consumption of natural resources in the production of concrete and, consequently, significantly reducing the environmental impact of both (construction and demolition waste and extracting natural aggregates). In other words, with this work, the intention is to evaluate the feasibility of producing high-performance self-compacting concrete with a less environmental impact, by replacing natural aggregates (NA) with fine and coarse recycled aggregates resulting from the precast industry, which allows the future use of this type of aggregates in the industrial process without reservations concerning the expected durability performance. To achieve these objectives, six types of self-compacting concrete (SCC) were produced incorporating different amounts of recycled aggregates. Six replacement ratios for fine recycled aggregates (FRA) and coarse recycled aggregates (CRA) were considered: (FRA/CRA) 0/0; 25/25; 50/50; 100/100; 0/100 and 100/0%. Six different tests were carried out to characterize both the main concrete transport mechanisms and the main concrete degradation mechanisms, namely: the immersion water absorption test, capillary water absorption test, oxygen permeability test, chloride migration test, electrical resistivity test and carbonation test. The obtained results clearly demonstrate that, despite the negative influence of the inclusion of recycled aggregates, it is still possible to produce high-performance self-compacting concrete with perfectly acceptable durability properties. Full article

(This article belongs to the Collection Utilization of Waste Materials in Building Engineering)

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5 pages, 171 KiB

Open AccessEditorial

Life Cycle Prediction and Maintenance of Buildings

by Jorge de Brito and Ana Silva

Buildings 2020, 10(6), 112; https://doi.org/10.3390/buildings10060112 - 23 Jun 2020

Cited by 12 | Viewed by 4205

Abstract

The sustainability of the built environment can only be achieved through the maintenance planning of built facilities during their life cycle, considering social, economic, functional, technical, and ecological aspects [...] Full article

(This article belongs to the Special Issue Life Cycle Prediction and Maintenance of Buildings)

8 pages, 4781 KiB

Open AccessArticle

The Effect of Vibro-Activation Time on the Properties of Highly Active Calcium Hydroxide

by Yaroslav Yakymechko, Iryna Lutsyuk, Roman Jaskulski, Judyta Dulnik and Tetyana Kropyvnytska

Buildings 2020, 10(6), 111; https://doi.org/10.3390/buildings10060111 - 16 Jun 2020

Cited by 6 | Viewed by 3168

Abstract

The results of studying the effect of the vibration processing time on the size of calcium hydroxide particles are given. The physicochemical processes affecting the size and morphology of calcium hydroxide particles have been studied. A stage-by-stage mechanism of the process of the [...] Read more.

The results of studying the effect of the vibration processing time on the size of calcium hydroxide particles are given. The physicochemical processes affecting the size and morphology of calcium hydroxide particles have been studied. A stage-by-stage mechanism of the process of the carbonation of lime, depending on its specific surface, is established. The results show that the optimal period for the vibration treatment of lime to obtain the most active material is 20 min. A longer period of vibration results in the merging of particles into larger agglomerates. Full article

(This article belongs to the Collection Advanced Concrete Materials in Construction)

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17 pages, 4040 KiB

Open AccessArticle

Optimum Design of RC Footings with Genetic Algorithms According to ACI 318-19

by German Solorzano and Vagelis Plevris

Buildings 2020, 10(6), 110; https://doi.org/10.3390/buildings10060110 - 11 Jun 2020

Cited by 18 | Viewed by 6802

Abstract

Engineers usually use trial-and-error approaches for dealing with design problems where they need to find the most economical design of a structural element in terms of its material cost while satisfying all the safety requirements imposed by the design codes. In this study, [...] Read more.

Engineers usually use trial-and-error approaches for dealing with design problems where they need to find the most economical design of a structural element in terms of its material cost while satisfying all the safety requirements imposed by the design codes. In this study, we employ a genetic algorithm (GA) with a dominance-based tournament selection technique for dealing with this design challenge. The methodology is applied in the design of reinforced concrete rectangular-shaped isolated footings in accordance with the American Concrete Institute ACI 318-19. First, the footing is encoded into a set of decision variables and an objective function is defined to compute the total cost based on the different construction materials. Then, the compliance of the design with the ACI 318-19 code is enforced by a constraint function that takes into consideration all the demand–capacity ratios for the different resistance requirements such as the allowable bearing pressure of the supporting soil, and the shear and flexural capacities of the footing, among others. Two numerical examples are presented where the results show a significant advantage in terms of material-cost and design-time reduction in comparison with the commonly used trial and error approach, proving the applicability of optimization algorithms (OAs) into the everyday design routine of the structural engineer. Full article

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16 pages, 1356 KiB

Open AccessArticle

Six-Steps Process of Structural Assessment of Heritage Timber Structures: Definition Based on the State of the Art

by Elena Perria and Mike Sieder

Buildings 2020, 10(6), 109; https://doi.org/10.3390/buildings10060109 - 08 Jun 2020

Cited by 9 | Viewed by 8165

Abstract

Each construction material deals with specific mechanical properties, their distribution, damage mechanisms, and degradation processes. Therefore, each material requires a particular assessment approach in order to derive a reliable description of the residual performance of the structure, correctly remove the cause of damage, [...] Read more.

Each construction material deals with specific mechanical properties, their distribution, damage mechanisms, and degradation processes. Therefore, each material requires a particular assessment approach in order to derive a reliable description of the residual performance of the structure, correctly remove the cause of damage, and proceed with the correct design of interventions. The aims of this paper are, first, the definition of a process of assessment and retrofitting of existing timber structures, both for engineered and heritage/traditional timber structures, and second, a comparison between the defined assessment process and its contents, and the content of existing guidelines, codes, and standards. In order to gain a definition of the process of assessment and retrofitting of existing timber structures, the content of scientific papers and articles was analyzed, and on this basis, an assessment process with six main steps and three milestones was developed. The content of the guidelines, codes and standards was afterwards analyzed basing on this six-steps assessment process. From a comparison among the current literature, guidelines, codes, and standards, interesting results emerged that gave us a picture of the European knowledge and interests on the assessment of existing timber structures. Not only agreement, but also discrepancies, variances, and incongruities were identified as possible topics for future research. Full article

(This article belongs to the Special Issue Structural Assessment of Timber Structures)

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26 pages, 2030 KiB

Open AccessReview

Decision Support Systems in Construction: A Bibliometric Analysis

by Muhammad Rashid Minhas and Vidyasagar Potdar

Buildings 2020, 10(6), 108; https://doi.org/10.3390/buildings10060108 - 08 Jun 2020

Cited by 14 | Viewed by 6395

Abstract

In recent years, the use of decision support systems for selecting sustainable construction materials in the building and commercial construction projects has received a great deal of attention. This paper reports an in-depth and systematic bibliometric analysis of the literature using Decision Support [...] Read more.

In recent years, the use of decision support systems for selecting sustainable construction materials in the building and commercial construction projects has received a great deal of attention. This paper reports an in-depth and systematic bibliometric analysis of the literature using Decision Support Systems (DSSs) for its construction, based on the papers published during the period from 2000 to 2016. The data were collected from two major databases, Web of Science (WoS) and Scopus, which included 2185 and 3233 peer reviewed articles, respectively. The analysis includes a general bibliometric analysis (publications output, country-wise research output, authorship, and collaboration patterns of these published articles). It also includes a citation analysis (keywords, most cited keywords, organizations, most cited articles, and average citations per article) and a network analysis (authors and countries). Overall, this study provides bibliometric insights and future research directions for researchers and practitioners who use DSSs. Full article

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21 pages, 1102 KiB

Open AccessArticle

Climate Adaptation in Maintenance Operation and Management of Buildings

by Steinar Grynning, Klodian Gradeci, Jørn Emil Gaarder, Berit Time, Jardar Lohne and Tore Kvande

Buildings 2020, 10(6), 107; https://doi.org/10.3390/buildings10060107 - 04 Jun 2020

Cited by 9 | Viewed by 4162

Abstract

The aim of this paper is to analyze the basic criteria, trends, applications, and developments related to climate adaptation in building maintenance and operation management (MOM) practices in Norway. Investigations conducted as part of the study include an analysis of current literature addressing [...] Read more.

The aim of this paper is to analyze the basic criteria, trends, applications, and developments related to climate adaptation in building maintenance and operation management (MOM) practices in Norway. Investigations conducted as part of the study include an analysis of current literature addressing climate adaptation in relation to MOM practices, supplemented by a review of existing research projects and initiatives in this field. Three case studies involving different Norwegian building owner organizations were examined in order to investigate the current status of the application and extent of climate adaptation practices in relation to MOM. The study has revealed a significant gap between theory and practice when it comes to integrating MOM in relation to climate adaptation. The concept of climate adaptation is only addressed as a high-level strategic issue. The case studies thus emphasize the need for a structured process that can enable the incorporation of climate adaptation in current MOM practices. This proposes a generic and structured climate-adaptive MOM framework that will enable the incorporation of climate adaptation in into corporate MOM practices at different scales and organizational levels. Implementation of this flexible and transferable framework is expected to provide a basis for accruing further knowledge on climate adaptation. Further work with the framework should include the introduction of more tangible and tailored tools and processes, including checklists or scoring systems accompanied by relevant climate adaptation factors and plans. Full article

(This article belongs to the Special Issue Life Cycle Prediction and Maintenance of Buildings)

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29 pages, 23170 KiB

Open AccessArticle

Structural Performance of Arched Space Trusses Using Date Palm Midribs for Light and Cost-Effective Construction in Egypt

by Eman A. Darwish, Yasser Mansour, Hamed Elmously, Amr Abdelrahman and Ayman Moustafa

Buildings 2020, 10(6), 106; https://doi.org/10.3390/buildings10060106 - 03 Jun 2020

Cited by 1 | Viewed by 5302

Abstract

Date palm midribs enjoy a long heritage among rural builders and craftsmen in Egypt for their abundance and low-cost. This familiarity encouraged previous studies to tackle the question of using date palm midribs in wide-span construction to provide simple, quick, cost efficient shaded [...] Read more.

Date palm midribs enjoy a long heritage among rural builders and craftsmen in Egypt for their abundance and low-cost. This familiarity encouraged previous studies to tackle the question of using date palm midribs in wide-span construction to provide simple, quick, cost efficient shaded structures. The design of tri-arched space truss was aimed to utilize date palm midribs in cost-efficient wide-span construction with minimal processing and maximum structural efficiency. However, the validated mechanical properties, the workability, the short-term and the long-term structural behaviors of the system are yet to be investigated. This paper investigates the structural behavior of a proposed tri-arched system using 1:3 scale specimens. The long-term environmental effects are also studied in one of the specimens. The specimens experienced high flexibility and gradual failure. A finite element model was created to predict the behavior of the specimens. The validated model was used to determine the structural behavior of the system with 12 m span. The system was found to be safe under the loads of wind and roofing. This paper is a part of a continuous process of validation that aims to utilize date palm midribs in contemporary wide-span construction to match the spirit of the youth in rural communities. Full article

(This article belongs to the Section Building Structures)

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14 pages, 3942 KiB

Open AccessArticle

Inhibition Effect of Tartrate Ions on the Localized Corrosion of Steel in Pore Solution at Different Chloride Concentrations

by Marina Cabrini, Sergio Lorenzi, Denny Coffetti, Luigi Coppola and Tommaso Pastore

Buildings 2020, 10(6), 105; https://doi.org/10.3390/buildings10060105 - 01 Jun 2020

Cited by 10 | Viewed by 3654

Abstract

The aim of this work is the evaluation of the inhibition effect of tartrate ions with respect to the localized corrosion of steel reinforcements in alkaline solution as a function of the concentration of chlorides ions. Weight loss tests and electrochemical tests were [...] Read more.

The aim of this work is the evaluation of the inhibition effect of tartrate ions with respect to the localized corrosion of steel reinforcements in alkaline solution as a function of the concentration of chlorides ions. Weight loss tests and electrochemical tests were carried out in saturated Ca(OH)₂ solution with NaOH at pH 12.7 and 13.2. The results only evidence a slight inhibition effect at pH 12.7, whereas at pH 13.2 the pitting onset is inhibited also for chloride concentration up to 3 M. Tartaric acid is a dicarboxylic acid with nucleophile substituents, which can act as a chelating agent both adsorbing on the surface of the passive film and forming a soluble complex with ferrous and ferric ions. Tartrate causes an increase in the passive current density but it prevents the depassivation of carbon steel due to the action of chlorides, thus preventing pitting initiation due to the competitive adsorption on metal surface. Full article

(This article belongs to the Special Issue Advances in Civil Engineering Materials: Design, Characterization, Corrosion and Durability)

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16 pages, 2230 KiB

Open AccessArticle

Non-commercial Air Purifier—The Effectiveness and Safety

by Anna Mainka, Walter Mucha, Józef S. Pastuszka, Ewa Brągoszewska and Agnieszka Janoszek

Buildings 2020, 10(6), 104; https://doi.org/10.3390/buildings10060104 - 31 May 2020

Cited by 5 | Viewed by 5976

Abstract

(1) Background: On the Internet, we can find the guidelines for homemade air purifiers. One of the solutions includes the use of a low-cost ozone generator to decrease the level of odors and biological contaminants. However, the authors do not notify about hazardous [...] Read more.

(1) Background: On the Internet, we can find the guidelines for homemade air purifiers. One of the solutions includes the use of a low-cost ozone generator to decrease the level of odors and biological contaminants. However, the authors do not notify about hazardous effects of ozone generation on human health; (2) Methods: We elaborated our test results on the bacterial and fungal aerosol reduction by the use of two technical solutions of homemade air purifiers. First, including a mesh filter and ozone generator, second including an ozone generator, mesh filter, and carbon filter. (3) Conclusions: After 20 min of ozone generation, the concentration of bacteria decreased by 78% and 48% without and with a carbon filter, while fungi concentration was reduced in the lower range 63% and 40%, respectively. Based on our test results, we proposed a precise periodical operation of homemade air purifier to maintain the permissible level of ozone for the occupants. Full article

(This article belongs to the Special Issue Novel Technologies to Enhance Energy Performance and Indoor Environmental Quality of Buildings)

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22 pages, 13166 KiB

Open AccessArticle

Experimental and Numerical Study of Behaviour of Reinforced Masonry Walls with NSM CFRP Strips Subjected to Combined Loads

by Houria Hernoune, Benchaa Benabed, Antonios Kanellopoulos, Alaa Hussein Al-Zuhairi and Abdelhamid Guettala

Buildings 2020, 10(6), 103; https://doi.org/10.3390/buildings10060103 - 31 May 2020

Cited by 9 | Viewed by 5472

Abstract

Near surface mounted (NSM) carbon fibers reinforced polymer (CFRP) reinforcement is one of the techniques for reinforcing masonry structures and is considered to provide significant advantages. This paper is composed of two parts. The first part presents the experimental study of brick masonry [...] Read more.

Near surface mounted (NSM) carbon fibers reinforced polymer (CFRP) reinforcement is one of the techniques for reinforcing masonry structures and is considered to provide significant advantages. This paper is composed of two parts. The first part presents the experimental study of brick masonry walls reinforced with NSM CFRP strips under combined shear-compression loads. Masonry walls have been tested under vertical compression, with different bed joint orientations 90° and 45° relative to the loading direction. Different reinforcement orientations were used including vertical, horizontal, and a combination of both sides of the wall. The second part of this paper comprises a numerical analysis of unreinforced brick masonry (URM) walls using the detailed micro-modelling approach (DMM) by means of ABAQUS software. In this analysis, the non-linearity behavior of brick and mortar was simulated using the concrete damaged plasticity (CDP) constitutive laws. The results proved that the application of the NSM-CFRP strips on the masonry wall influences significantly strength, ductility, and post-peak behavior, as well as changing the failure modes. The adopted DMM model provides a good interface to predict the post peak behavior and failure mode of unreinforced brick masonry walls. Full article

(This article belongs to the Special Issue Sustainable and Green Construction Materials: Opportunities for New and Existing Structures)

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22 pages, 2766 KiB

Open AccessArticle

Methodology for Evaluation and Development of Refurbishment Scenarios for Multi-Story Apartment Buildings, Applied to Two Buildings in Denmark and Switzerland

by Yovko Ivanov Antonov, Per Heiselberg, Flourentzos Flourentzou and Michal Zbigniew Pomianowski

Buildings 2020, 10(6), 102; https://doi.org/10.3390/buildings10060102 - 31 May 2020

Cited by 8 | Viewed by 4444

Abstract

Renovation of existing buildings is an indispensable part of achieving European efficiency and environmental targets. This paper applies different assessment methodologies to find optimal renovation, given different evaluation criteria. The performed literature study identifies the cost-optimal methodology employing Life Cycle Cost (LCC) calculation [...] Read more.

Renovation of existing buildings is an indispensable part of achieving European efficiency and environmental targets. This paper applies different assessment methodologies to find optimal renovation, given different evaluation criteria. The performed literature study identifies the cost-optimal methodology employing Life Cycle Cost (LCC) calculation as one of the most common assessment methods. This paper proposes a new renovation assessment method targeted to the early design phases of specific building projects. The method has a simple structure, and can be used as a roadmap of necessary activities for obtaining solid building knowledge and required energy and cost calculations. The methodology is based on linking economic and energy efficiency parameters into defined cost-effective value, calculated for all investigated renovation actions. The cost-effectiveness value is used for ranking and selecting the most appropriate single renovation actions to form renovation packages, which can be further examined in detail (for example, with LCC). To demonstrate the method, evaluate the strengths, and identify the weaknesses, it is applied to case study buildings in Denmark and Switzerland. The results show that, in the initial stage, the proposed cost-effectiveness representation can be used successfully to compare and evaluate different envelope elements and systems. Cost-effectiveness also provides rational results on a package level. Further work is still required in the area of evaluation of energy supply and renewable energy production systems. Full article

(This article belongs to the Section Building Energy, Physics, Environment, and Systems)

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20 pages, 3878 KiB

Open AccessArticle

Comparative Study Involving Effect of Curing Regime on Elastic Modulus of Geopolymer Concrete

by Peiman Azarsa and Rishi Gupta

Buildings 2020, 10(6), 101; https://doi.org/10.3390/buildings10060101 - 30 May 2020

Cited by 15 | Viewed by 5003

Abstract

Geopolymer Concrete (GPC) as a cement-less construction material has attracted worldwide attention due to its lower carbon footprint. There are numerous studies reported on GPC made using different by-products including fly-ash. However, since the use of bottom-ash is comparatively limited, making potassium-based GPC [...] Read more.

Geopolymer Concrete (GPC) as a cement-less construction material has attracted worldwide attention due to its lower carbon footprint. There are numerous studies reported on GPC made using different by-products including fly-ash. However, since the use of bottom-ash is comparatively limited, making potassium-based GPC using this waste can be an alternative to Portland Cement Concrete (PCC). In this study, two methods of accelerated curing were used to determine the influence of elevated temperature on the compressive strength of GPC, composed of 50% bottom-ash and 50% fly-ash. GPC specimens were cured using various temperatures including ambient, 30 °C, 45 °C, 60 °C, and 80 °C for 24 h, all followed by 28 days of ambient curing. The highest compressive strength was obtained with steam curing at a temperature of 80 °C for a duration of 24 h. It is of great significance to evaluate elastic modulus of the concrete mixture so that the short-term rigidity of structures subjected to elongation, bending, or compression can be predicted. In this study, a longitudinal Resonant Frequency Test (RFT) as a non-destructive test (NDT) was used to calculate the elastic modulus of both GPC and a comparative PCC mix. Based on the results, PCC had higher resonant frequency (by about 1000 Hz) compared to GPC. A review of empirical models for predicting GPC’s elastic modulus showed that all of the predicted elastic modulus values were lower than experimental values. Full article

(This article belongs to the Section Building Materials, and Repair & Renovation)

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19 pages, 8263 KiB

Open AccessArticle

Influence of Reinforcing Steel Corrosion on Life Cycle Reliability Assessment of Existing R.C. Buildings

by Pietro Croce, Paolo Formichi and Filippo Landi

Buildings 2020, 10(6), 99; https://doi.org/10.3390/buildings10060099 - 28 May 2020

Cited by 17 | Viewed by 4019

Abstract

Time-dependent reliability assessment is a crucial aspect of the decision process for rehabilitation of existing reinforced concrete structures. Since the assessment strongly depends on degradation of materials with time, the paper focuses on the influence of corrosion in reinforcing steel on time-reliability curves [...] Read more.

Time-dependent reliability assessment is a crucial aspect of the decision process for rehabilitation of existing reinforced concrete structures. Since the assessment strongly depends on degradation of materials with time, the paper focuses on the influence of corrosion in reinforcing steel on time-reliability curves of relevant reinforced concrete (r.c.) structures, built in Italy in the 1960s, belonging to different building categories. To realistically represent the probability distribution functions (pdfs) of the relevant properties of reinforcing steel and concrete commonly adopted in the 1960s, stochastic models for steel yielding and concrete compressive strength have been derived, by means of a suitable cluster analysis, from secondary databases of test results gathered at that time in Italy on concrete and steel rebar specimens. This cluster analysis, based on Gaussian mixture models, provides a powerful tool to “objectively” extract material classes and associated probability density functions from databases of experimental test results. In the study, different degradation conditions and several reinforcing steel and concrete classes are considered, also aiming to scrutinize their influence on the time-dependent reliability curves. Finally, to stress the significance of the study, the time-dependent reliability curves so obtained are critically examined and discussed also in comparison with the target reliability levels currently adopted in the Eurocodes. Full article

(This article belongs to the Special Issue Life Cycle Prediction and Maintenance of Buildings)

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23 pages, 1185 KiB

Open AccessEditor’s ChoiceReview

Building Information Modelling (BIM) to Enhance Occupational Safety in Construction Activities: Research Trends Emerging from One Decade of Studies

by Mario Fargnoli and Mara Lombardi

Buildings 2020, 10(6), 98; https://doi.org/10.3390/buildings10060098 - 28 May 2020

Cited by 57 | Viewed by 15859

Abstract

In recent years, the use of new technologies is rapidly transforming the way working activities are managed and carried out. In the construction industry, in particular, the use of Building Information Modelling (BIM) is ever increasing as a means to improve the performances [...] Read more.

In recent years, the use of new technologies is rapidly transforming the way working activities are managed and carried out. In the construction industry, in particular, the use of Building Information Modelling (BIM) is ever increasing as a means to improve the performances of numerous activities. In such a context, several studies have proposed BIM as a key process to augment occupational safety effectively, considering that the construction industry still remains one of the most hazardous working sectors. The purpose of the present study is to investigate the recent research addressing the use of BIM to improve construction safety. A systematic review was performed considering journal papers that appeared in literature in the last decade. The results showed that the most viable and promising research directions concern knowledge-based solutions, design for safety improvement through BIM solutions, transversal applications of BIM, and dynamic visualization and feedback. The findings of this study also indicated that more practical BIM applications are needed, especially focusing on safety training and education, the use of BIM to augment safety climate and resilience, and the development of quantitative risk analysis to better support safety management. Overall, the study provided a comprehensive research synthesis augmenting knowledge on the role of BIM-based tools in construction safety, which can be considered a reference framework to enhance workers’ safety by means of these new technologies. Full article

(This article belongs to the Special Issue Application of Computer Technology in Buildings)

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17 pages, 2120 KiB

Open AccessArticle

Profitability of Various Energy Supply Systems in Light of Their Different Energy Prices and Climate Conditions

by Elaheh Jalilzadehazhari, Georgios Pardalis and Amir Vadiee

Buildings 2020, 10(6), 100; https://doi.org/10.3390/buildings10060100 - 28 May 2020

Cited by 4 | Viewed by 3441

Abstract

The majority of the single-family houses in Sweden are affected by deteriorations in building envelopes as well as heating, ventilation and air conditioning systems. These dwellings are, therefore, in need of extensive renovation, which provides an excellent opportunity to install renewable energy supply [...] Read more.

The majority of the single-family houses in Sweden are affected by deteriorations in building envelopes as well as heating, ventilation and air conditioning systems. These dwellings are, therefore, in need of extensive renovation, which provides an excellent opportunity to install renewable energy supply systems to reduce the total energy consumption. The high investment costs of the renewable energy supply systems were previously distinguished as the main barrier in the installation of these systems in Sweden. House-owners should, therefore, compare the profitability of the energy supply systems and select the one, which will allow them to reduce their operational costs. This study analyses the profitability of a ground source heat pump, photovoltaic solar panels and an integrated ground source heat pump with a photovoltaic system, as three energy supply systems for a single-family house in Sweden. The profitability of the supply systems was analysed by calculating the payback period (PBP) and internal rate of return (IRR) for these systems. Three different energy prices, three different interest rates, and two different lifespans were considered when calculating the IRR and PBP. In addition, the profitability of the supply systems was analysed for four Swedish climate zones. The analyses of results show that the ground source heat pump system was the most profitable energy supply system since it provided a short PBP and high IRR in all climate zones when compared with the other energy supply systems. Additionally, results show that increasing the energy price improved the profitability of the supply systems in all climate zones. Full article

(This article belongs to the Special Issue Life Cycle Prediction and Maintenance of Buildings)

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16 pages, 10825 KiB

Open AccessArticle

Technical and Economic Analysis of the Implementation of Selected Variants of Road Investment

by Marcin Szczepański and Beata Grzyl

Buildings 2020, 10(6), 97; https://doi.org/10.3390/buildings10060097 - 26 May 2020

Cited by 1 | Viewed by 2886

Abstract

The aim of the article is to analyze three variants of modernization and reconstruction of a road intersection, which in practice is the cause of numerous collisions and accidents. Detailed design solutions are presented for them. The aim of the analyses is to [...] Read more.

The aim of the article is to analyze three variants of modernization and reconstruction of a road intersection, which in practice is the cause of numerous collisions and accidents. Detailed design solutions are presented for them. The aim of the analyses is to indicate an effective solution that, taking into account technical modifications of the road system elements, will ensure the functionality of the road system to the highest degree and significantly reduce the number of road incidents. To indicate the optimal solution, quantitative data (cost and duration of activities for three options) and qualitative data (determined based on the own experience and knowledge of road industry experts) is analyzed. The authors refer to many criteria of various natures (e.g., economic, technical, functional, environmental, social), which allow for comprehensive consideration of the current requirements of road users and changing circumstances, among others a steady increase in the number of vehicles and growing social expectations in terms of road parameters. Considering the presented analyses and arguments, the authors recommend option 1 as optimal. This is the most expensive solution among those analyzed and with the longest implementation time, however, taking into account the long-term prognosis of the direction and scope of changes to the existing standards and requirements for road infrastructure, it can be stated that option 1 meets them to the highest degree, and also has the greatest potential. The envisaged solution ensures high standards of the quality of road infrastructure use in terms of functionality, capacity, technical parameters, as well as the safety of traffic participants related to the smoothness of the journey, reduction of the number of collisions and accidents. Full article

(This article belongs to the Collection Construction Management – Future Innovations, Methods, Techniques and Technologies)

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