Editor’s Choice Articles

Urban vegetation provides undeniable benefits to urban climate, health, thermal comfort and environmental quality of cities and represents one of the most considered urban heat mitigation measures. Despite the plethora of available scientific information, very little is known about the holistic and global impact of a potential increase of urban green infrastructure (GI) on urban climate, environmental quality and health, and their synergies and trade-offs. There is a need to evaluate globally the extent to which additional GI provides benefits and quantify the problems arising from the deployment of additional greenery in cities which are usually overlooked or neglected. The present paper has reviewed and analysed 55 fully evaluated scenarios and case studies investigating the impact of additional GI on urban temperature, air pollution and health for 39 cities. Statistically significant correlations between the percentage increase of the urban GI and the peak daily and night ambient temperatures are obtained. The average maximum peak daily and night-time temperature drop may not exceed 1.8 and 2.3 °C respectively, even for a maximum GI fraction. In parallel, a statistically significant correlation between the peak daily temperature decrease caused by higher GI fractions and heat-related mortality is found. When the peak daily temperature drops by 0.1 °C, then the percentage of heat-related mortality decreases on average by 3.0% The impact of additional urban GI on the concentration of urban pollutants is analysed, and the main parameters contributing to decrease or increase of the pollutants’ concentration are presented. Full article

Additive manufacturing, including 3D printing (3DP), is one of the critical pillars of Industry 4.0 and the next construction revolution. Several countries, including China, have utilized 3DP on larger scales or real projects. However, reviews of the lessons learned from previous large-sized practices of 3DP utilization are scarce. This paper presents a few practical applications of implementing 3DP over the past decade and suggests a direction for future research work. Recent publications on 3DP practices are systematically reviewed using an interpretivist philosophical lens, and more specifically, the nozzle characteristics are focused upon. The Scopus and China National Knowledge Infrastructure (CNKI) journal databases are utilized, resulting in the examination of 54 English and 62 Chinese papers. The selected practices from Mainland China, Hong Kong, Taiwan and Macao are considered for this review. A content critical review approach is adopted, and the identified papers are critically reviewed. These papers reported key challenges and advantages from their reported practices, such as limitations in aggregate sizes, nozzle sizes, standards, post-occupancy satisfaction, final product quality, productivity challenges and other associated risks. The paper reports upon prominent limitations and signposts directions for future investigations. Full article

Off-site construction (OSC) is known as an efficient construction method that could save time and cost, reduce waste of resources, and improve the overall productivity of projects. Coupled with digital technologies associated with the Industry 4.0 concept, OSC can offer a higher rate of productivity and safety. While there is a rich literature focusing on both OSC and Industry 4.0, the implementation of associated digital technologies in the OSC context has not been fully evaluated. This paper intends to evaluate the current literature of digital technology applications in OSC. Scientometric analyses and a systematic review were carried out evaluating fifteen typical digital technologies adopted by OSC projects, including building information modelling (BIM), radio frequency identification devices (RFID), global positioning systems (GPS), the Internet of Things (IoT), geographic information systems (GIS), sensors, augmented reality (AR), virtual reality (VR), photogrammetry, laser scanning, artificial intelligence (AI), 3D printing, robotics, big data, and blockchain. This review formulates a clear picture of the current practice of these digital technologies and summarizes the main area of application and limitations of each technology when utilized in OSC. The review also points out their potential and how they can be better adopted to improve OSC practice in the future. Full article

Reinforced concrete (RC) frame buildings with masonry infills represent one of the most common structural typologies worldwide. Although, in the past, masonry infills were frequently considered as non-structural elements and their interaction with the structure was neglected, earthquakes occurring over the last decades have demonstrated the important role of these elements in the seismic response of all RC-infilled building typologies. In this regard, the selection of the most suitable numerical modelling approaches to reproduce the hysteretic response of the masonry infills—and their interaction with the RC frames—is still an open issue. To deal with this issue, in this study, a macro-classification based on different available databases of experimental tests on infilled RC frames, is firstly proposed to understand the variability in the infill properties and the corresponding numerical modelling uncertainties. Five masonry infill types are selected as representative for the typical existing configurations in Italy and other Mediterranean countries. Three of those masonry infill types are then selected to carry out a more detailed analysis, namely their numerical modelling validation using experimental testing results, considering and comparing the main formulations available in the literature for the definition of the hysteretic behaviour of infills. From such a comparison, the model that minimizes the prediction error, according to specific features of the selected masonry infill, is identified for each masonry infill type. Full article

Evaluating and optimising human comfort within the built environment is challenging due to the large number of physiological, psychological and environmental variables that affect occupant comfort preference. Human perception could be helpful to capture these disparate phenomena and interpreting their impact; the challenge is collecting spatially and temporally diverse subjective feedback in a scalable way. This paper presents a methodology to collect intensive longitudinal subjective feedback of comfort-based preference using micro ecological momentary assessments on a smartwatch platform. An experiment with 30 occupants over two weeks produced 4378 field-based surveys for thermal, noise, and acoustic preference. The occupants and the spaces in which they left feedback were then clustered according to these preference tendencies. These groups were used to create different feature sets with combinations of environmental and physiological variables, for use in a multi-class classification task. These classification models were trained on a feature set that was developed from time-series attributes, environmental and near-body sensors, heart rate, and the historical preferences of both the individual and the comfort group assigned. The most accurate model had multi-class classification F1 micro scores of 64%, 80% and 86% for thermal, light, and noise preference, respectively. The discussion outlines how these models can enhance comfort preference prediction when supplementing data from installed sensors. The approach presented prompts reflection on how the building analysis community evaluates, controls, and designs indoor environments through balancing the measurement of variables with occupant preferences in an intensive longitudinal way. Full article

The development of technologies associated with the fourth industrial revolution is rapid. Construction 4.0 represents the architecture, engineering, construction and operations industries exploration of new technologies, equivalent to Industry 4.0 for the manufacturing industry. These concepts address multiple perspectives besides the technological, such as management and processes. The purpose of this study was to investigate to what extent research regarding construction projects addresses information and communication, automatisation or industrialisation technologies. A scoping review was the method used to perform a quantitative analysis of over two thousand journal papers published from 2015 onwards. The results show that new technologies are addressed separately, while synergy studies are uncommon. Longitudinal analyses show that there was no significant increase in journal papers concerning new technologies from 2015 to 2019. Information and communication was the search criterion with the least number of papers found. The environmental perspective of new technologies was present but the least common from 2019 to 2020. Hence, this review shows that there is an extensive research gap regarding Construction 4.0 technologies in the context of construction projects. Studies regarding synergy and environmental effects of new technologies should increase to start the progress towards a successful entry into the fourth industrial revolution. Full article

The study presents a didactic experience for the deep refurbishment and the revitalization of the San Siro neighborhood in Milan (Italy). The public housing is a significative example of the 20th-century architecture (also named “Italian Modernism of Architecture”), designed by the Italian architects—Franco Albini, Renato Camus, Giancarlo Palanti, and Laslo Kovacs (1938–1941). Nowadays, it is a multicultural area, characterized by the presence of a fragile population, with strong socio-spatial inequalities, intercultural and intergenerational conflicts. Here, an architectural design project is realized, experimenting with innovative and up-to-date design solutions. This experience develops a sensitive awareness of the multidimensional complexity of the environmentally responsible design, which requires a critical balance among different disciplines and skills. The reusing of existing buildings has sustainable importance for preventing new land-uses and for saving the potential energy consumption related to the construction process. Only a widespread knowledge of the local socio-economic conditions through participatory actions permits the selection of appropriate retrofit solutions, considering also the high cultural, social, and economic values. Functional and social mix, space flexibility, green design, renewable energies, circular economy criteria, and continuative maintenance are the correct strategies for boosting the social revitalization and for improving fairness, safety, architectural quality, human comfort, energy efficiency, and sustainability in this public housing neighborhood. Full article

Carbon emissions are categorised as Embodied Carbon (EC) occurring in the production phase and Operational Carbon (OC) occurring in the operational phase of buildings. The current focus on producing zero-carbon buildings, emphasises reducing OC and ignores the importance of reducing EC emissions. This study focuses on EC. Methods available in EC estimating currently produce estimates that often do not complement each other. This makes it important to develop a robust and accurate methodology for estimating EC. Blockchain is an emerging technology that has significant potential for transaction processing in supply chains. The construction industry being the second least digitalised industry, the adoption of innovative technologies is predominantly important. This paper explores the potential application of blockchain for accurate estimation of EC in construction supply chains. A detailed literature review and expert interviews revealed that, compared to traditional information systems, blockchain systems could eliminate issues in EC estimating highlighting its potential credible application for EC estimating. Scalability was identified as a feature that was lacking in a blockchain system, however, for EC estimating, its impact was identified as minimal. It will be difficult to generalise the findings of the study due to interview based qualitative methodology adopted in this study along with the fact that blockchain is an emerging and fairly new technology. However, a similar process could be followed by other studies to compare blockchain with traditional information systems, to evaluate the suitability of blockchain technology to develop prototype systems. Full article

Air ventilation rate plays a relevant role in maintaining adequate indoor air quality (IAQ) conditions in public buildings. In general, high ventilation rates ensure good indoor air quality but entail relevant energy consumption. Considering the necessity of balancing IAQ and energy consumption, a correlation between the number of occupants obtained from analysis of CO₂ concentration variation is presented as a general element for controlling the operation of heating ventilation and air cooling (HVAC) systems. The specific CO₂ exhalation rate is estimated using experimental data in some real conditions in university classrooms. A method for the definition of optimal values of air exchange rate is defined, highlighting that the obtained values are much lower than those defined in current technical standards with possibilities of relevant reduction of the total energy consumption. Full article

In this paper, we present a simulation-based approach for effectively estimating delay risks in project schedules and predicting the possibilities of in-time project completion for various deadlines. The main contribution of this study is the development of a novel approach for duration risk quantification, which uses a newly introduced equation for total risk estimation regarding activities’ durations, and quantifying the manager’s experience as expressed through a questionnaire. In addition, the proposed approach integrates these preferences into a simulation-based framework used for estimating the activities’ durations variation and predicting the actual project duration with more accuracy. Furthermore, using different distributions according to each activity characteristic supports decision making from a wide range of experts, from risk-averse to risk-seeking managers. The proposed method was applied to estimate the total project completion time of a complicated hotel renovation project and the possibility for the project to be delivered within an imposed deadline. The promising results in comparison to the classic PERT method proved that this process can better express the uncertainty and provide project risk managers with better predictions when estimating budget and time-critical overruns under lack of knowledge and historical data. Full article

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

Sustainable building practices are rooted in the need for reliable information on the long-term performance of building materials; specifically, the expected service-life of building materials, components, and assemblies. This need is ever more evident given the anticipated effects of climate change on the built environment and the many governmental initiatives world-wide focused on ensuring that structures are not only resilient at their inception but also, can maintain their resilience over the long-term. The Government of Canada has funded an initiative now being completed at the National Research Council of Canada’s (NRC) Construction Research Centre on “Climate Resilience of Buildings and Core Public infrastructure”. The outcomes from this work will help permit integrating climate resilience of buildings into guides and codes for practitioners of building and infrastructure design. In this paper, the impacts of climate change on buildings are discussed and a review of studies on the durability of building envelope materials and elements is provided in consideration of the expected effects of climate change on the longevity and resilience of such products over time. Projected changes in key climate variables affecting the durability of building materials is presented such that specifications for the selection of products given climate change effects can be offered. Implications in regard to the maintainability of buildings when considering the potential effects of climate change on the durability of buildings and its components is also discussed. Full article

Rubble stone masonry walls are widely diffused in most of the cultural and architectural heritage of historical cities. The mechanical response of such material is rather complicated to predict due to its composite nature. Vertical compression tests, diagonal compression tests, and shear-compression tests are usually adopted to investigate experimentally the mechanical properties of stone masonries. However, further tests are needed for the safety assessment of these ancient structures. Since the relation between normal and shear stresses plays a major role in the shear behavior of masonry joints, governing the failure mode, a triplet test configuration is herein investigated. First, the experimental tests carried out at the laboratory of the University of L’Aquila on stone masonry specimens are presented. Then, the triplet test is simulated by using the total strain crack model, which reflects all the ultimate states of quasi-brittle material such as cracking, crushing, and shear failure. The goal of the numerical investigation is to evaluate the shear mechanical parameters of the masonry sample, including strength, dilatancy, normal, and shear deformations. Furthermore, the effect of (i) confinement pressure and (ii) bond behavior at the sample-plate interfaces are investigated, showing that they can strongly influence the mechanical response of the walls. Full article

External thermal insulation systems (ETICS) are relevant facade applications of functional components allowing to reduce energy consumption in buildings to fulfill the provisions of nearly Zero-Energy Buildings (nZEBs). ETICS systems generally are made of adhesives, thermal insulation material, renders with mesh reinforcement, primers, and finish coats. Their main parameters are thermal characteristics and durability, both determined by the specific composition of the systems. Growing concerns on the environment and depletion of natural resources drive the need for the determination of the environmental characteristic of ETICS due to its growing market demand. This analysis focuses on a life cycle assessment (LCA) of a commonly used EPS based ETICS system with four different renderings, produced in several locations. The scope of this study concerns raw materials extraction, transport, production, and energy provision up to the finished, packed, and ready-for-sale product at the factory gate. The authors compared the environmental impact allocated to the 1 m² of the produced system by taking into account the thickness of EPS and within different environmental impact categories. The results of the current impacts were compared to those obtained five years earlier, considering the technological and environmental progress of the production process. Full article

The implementation of sustainable solutions in the design of buildings is one of the main elements in achieving the transition to sustainability. The variety of structural elements and availability of sustainable materials, and the different preferences of clients, architects, and structural designers make the decision-making process difficult. This research aims to develop a decision model for applying to the early design stage. This work evaluates the sustainability of the load-bearing structures of a commercial building. Three types of load-bearing structures have been selected and compared concerning different physical parameters, cost of construction, cost of materials, technological dimensions (duration expressed in person-hours and machine-hours), and environmental impact. The methodology combines the building information modeling, sustainability criteria, and multi-criteria decision-aiding methods. The presented case study illustrates the proposed approach. The study revealed that multi-criteria decision aiding methods give the possibility to improve the selection process and to assess the sustainability of alternative structural solutions at an early stage of building design. The proposed decision model is versatile and therefore can be applied for different cases. Full article

Assessment regarding the impact of Energy Performance Certificates (EPC) on the residential market is largely inconclusive; while the majority of hedonic analyses have found EPC ratings to be correlated with prices, opinion-based research has found a negligible impact on prices and other marketing variables. Using the opinion of qualified real estate agents, this paper explores whether, in Spain, EPC labels play any role in housing marketing, as well as the policy changes required to foster efficient dwellings. The results reveal a large misunderstanding of the EPC labels, since they are seen as a global home-quality indicator, while their impact on residential marketing is quite poor. Apparently, both supply and demand place a small interest in energy performance, although it is slightly larger for sellers/buyers in relation to lenders/tenants. In any case, EPC labels are far from blurring the energy information asymmetry, since most of the buyers/tenants are informed of the EPC rating after having selected their home. Overall, the EPC scheme has a poor reputation exacerbated by inaccuracies, unintelligible units to express the financial and environmental implications of energy efficiency, and an apparent weak supervision. These findings stress the need to improve the scheme; in doing so, realtors suggest the need for some companion policies. Full article

The article compared the test results of a number of features determining the durability of rammed earth durability in a humid continental climate. The results of wet to dry compressive strength ratio, frost resistance, linear shrinkage, resistance to erosion under the influence of a stream of pressurized water, and resistance to erosion under the influence of cyclic wetting and drying were presented. All of the tests were done on the same soil-cement mixture. On this basis, it was determined which of the methods of durability assessment is more and which is less restrictive. A new method for assessing the durability of CSRE in a humid continental climate has been proposed, which is the frost resistance test. This test is determined by the method that is described in the national annex of the European concrete standard of one of the temperate climate countries. The article also shows that a minimum of 9% of the cement additive and a soil mixture containing a gravel fraction are required, in order to ensure adequate rammed earth durability in a humid continental climate (i.e., frost resistance). Full article

This article presents the use of TLS (LiDAR) measurement for the evaluation of the technical conditions of a historic building. A FARO M70 laser scanner was used in the study. The measurements was taken as an RCP point cloud. The measurement allowed to partially determine the cause of the building damage. The performed measurement allows to propose a precise solution that could be pre-fabricated. The study shows the usefulness of TLS in building diagnostics. Improper measurement could lead to a wrong solution and a certain degree of uncertainty. Full article

This article discusses the visual perception of selected buildings located in the historic centre of Cologne, Germany, that have been designed by outstanding architects. It presents eye-tracking research, both from a theoretical perspective and that of its application potential in, among other fields, psychology, management, architecture and urban planning. It also presents an experiment which was performed to evaluate the suitability of eye tracking in the assessment of the visual perception of architecture and its surroundings, utilising the case study method and members of Generation Z as the subject population. Analysis of the experiment’s results enabled the authors to formulate commentary on findings concerning typically observed attractors and distractors in the perception of architecture and its surroundings depending on context-specific conditions. The study provided evidence of the suitability of eye tracking in the assessment of the visual perception of works of architecture and indicated the possibility of continuing research concerning the assessment and shaping of the state of awareness and knowledge of architecture and urban planning, which can significantly affect public participation in urban governance. Full article

The present paper presents a SWOT analysis, the aim of which is to evaluate the strategic implementation of BIM technology in the construction industry in Poland. The authors created a SWOT matrix presenting strengths, weaknesses, opportunities, and risks associated with the use of BIM. Using literature analyses, own experience, and market reports, all elements of the SWOT matrix are described in detail. Basic indicators characterizing the strategic position of BIM on the Polish construction market are calculated. Finally, the matrix of strategic tasks and actions that should be applied in order to promote and develop BIM in Poland are defined. Full article

Non-destructive testing (NDT) and semi-destructive testing (SDT) have recently been more frequently used for the evaluation and condition assessment of concrete floors in various types of buildings. The subject of the article is to briefly introduce the reader to the problem of adhesion between overlays and substrates in concrete floors and to illustrate the current state of knowledge on the subject. The aim of this paper was to briefly describe the recently used non-destructive and semi-destructive testing methods and the parameters useful for characterizing the adhesion between overlays and substrates in concrete floors, as well as the methods useful to characterize the functional properties of the overlays. A recent literature survey, related to the adhesion between the overlays and substrates in concrete floors, is thus shown. Special emphasis was placed on the critical review of the current research results. Based on the analysis of the literature review, research gaps have been presented in order to highlight future research directions. Full article

The growing pressure to ensure sustainable construction is also associated with stricter demands on the cost-effectiveness of construction and operation of buildings and reduction of their environmental impact. This paper presents a methodology for building life cycle cost estimation that enables investors to identify the optimum material solution for their buildings on the level of functional parts. The functionality of a comprehensive model that takes into account investor requirements and links them to a construction cost estimation database and a facility management database is verified through a case study of a “façade composition” functional part, with sublevel “external thermal insulation composite system (ETICS) with thin plaster”. The results show that there is no generally applicable optimum ETICS material solution, which is caused by differing investor requirements, as well as the unique circumstances of each building and its user. The solution presented in this paper aims to aid investor decision-making regarding the choice of the building materials while taking the Life Cycle Cost (LCC) into account. Full article

Used properly, daylight can provide visual comfort, reduce energy consumption and improve health and safety at work. This paper investigates the influence that different roof types, (i.e., sawtooth roof, skylight and monitor), have on daylight levels, along with the construction cost in an industrial environment in Athens, Greece. Construction costs and daylight adequacy/uniformity are antagonistic phenomena, since as the distance between the roof openings increases, the construction cost is minimised, while the daylight levels and the uniformity are reduced. Therefore, an optimisation method is proposed in order to find the optimum distance between the roof openings. The selected building is a representative unit of Greek industrial facilities, while the optimisation method is based upon a multiparametric approach. This consists of three (3) different roof opening arrangement types with different geometric characteristics. The daylight metrics used are the Daylight Area, the Daylight Factor, the Mean Daylight Autonomy, the Uniform Daylight Index and the Annual Sunlight Exposure. Overall, sawtooth roofs represent the best choice for daylight provision in industrial buildings at the examined geographic location. Using the aforementioned optimisation method, the optimum solution of distances between the roof openings ranges from 10 m to 13 m. Full article

Blockchain Technology (BCT) is a growing digital technology that in recent years has gained widespread traction in various industries in the public and private sectors. BCT is a decentralized ledger that records every transaction made in the network, known as a ‘block’, the body of which is comprised of encrypted data of the entire transaction history. BCT was introduced as the working mechanism that forms the operational basis of Bitcoin, the first digital cryptocurrency to gain mainstream appeal. The introduction of decentralized data exchange technology in any industry would require strengthened security, enforce accountability, and could potentially accelerate a shift in workflow dynamics from current centralized architectures to a decentralized, cooperative chain of command and affect a cultural and societal change by encouraging trust and transparency. BCT aims at creating a system that would offer a robust self-regulating, self-monitoring, and cyber-resilient data transaction operation, assuring the facilitation and protection of a truly efficient data exchange system. In the state of Florida, climate change and unpredicted weather disasters have put pressure on state and local decision-makers to adapt quick and efficient post-disaster recovery systems. Part of the recovery efforts is the reconstruction of buildings and infrastructure. The introduction of new technologies in the Architecture, Engineering, and Construction (AEC) industry can contribute to addressing recovery and rebuilding after the event of a natural disaster. With parallel technological advancement in geospatial data and Geographic Information System (GIS), as well as worsening climatic conditions, concerns can be suitably addressed by employing an integrated system of both Building Information Modeling (BIM) and BCT. While several potential applications of BIM must provide solutions to disaster-related issues, few have seen practical applications in recent years that indicate the potential benefits of such implementations. The feasibility of BIM-based applications still rests on the reliability of connectivity and cyber-security, indicating a strong use case for using BCT in conjunction with BIM for post-disaster recovery. This research depicts a survey of BCT and its applications in the Architecture, Engineering, and Construction (AEC) industries and examines the potential incorporation within the BIM process to address post-disaster rebuilding problems. Moreover, the study investigates the potential application of BCT in improving the framework for automating the building permitting process using Smart Contract (SC) technologies and Hyperledger Fabric (HLF), as well as discussing future research areas. The study proposes a new conceptualized framework resulting from the integration of BCT and BIM processes to improve the efficiency of building permit processes in post-disaster events. Full article

The effectiveness of slightly reinforced thin U-shaped cementitious mortar jacketing for the repair of damaged shear-critical reinforced concrete beams is experimentally investigated. The test project includes two parts. In the first one, five concrete beams over-reinforced against flexure and under-reinforced against shear with different ratio of closed stirrups were initially subjected to monotonic loading until failure. The initially tested beams have been designed to fail in shear after wide diagonal cracking and to exhibit various strength and deformation capacities along with different levels of damages. In the second experimental part, the heavily damaged beams were jacketed with mild steel small diameter U-shaped transverse stirrups and longitudinal reinforcing bars. The retrofitted specimens using the proposed jacketing technique were tested again following the same four-point-bending load scheme. Based on the overall performance of the beams, it is deduced that the shear strength and deformation capability of the jacketed beams were substantially increased compared to the corresponding capacities of the initial beams. Further, although all beams failed in a shear abrupt manner, the retrofitted ones exhibited reduced brittleness and higher deflections at failure up to six times with respect to the initially tested specimens. The level of the initial damage influences the efficiency of the jacketing. Additional test data derived from relative shear-damaged beam specimens and retrofitted with similar thin jackets is also presented herein in order to establish the effectiveness of this repair system and to clarify the parameters affecting its structural reliability. Comparisons indicated that jacketed beams can alter the failure mode from brittle shear to ductile flexural under certain circumstances. Full article

There are currently no standards regulating water management for mass timber elements during construction, little knowledge of impacts of moisture exposure (wetting and drying performance, dimensional stability, checking), and few precedents serving as guidelines for monitoring moisture response of mass timber. To address these gaps, a hygrothermal monitoring study was devised to track moisture performance of U.S. made cross laminated timber (CLT) and glulam at a three-story mass timber building. This paper discusses moisture measurements that were collected during the first six months of construction at a CLT rocking shear wall and a timber floor connection. Despite the limited number of structural systems monitored during construction, the distribution and number of sensors in these elements allow to draw some important conclusions. The data confirmed that moisture distribution and wetting/drying rates varied based on local conditions and details (aspect, coatings, connections, etc.), with measurements at an uncoated, north-facing area showing the highest moisture levels (reaching fiber saturation at multiple ply depths and locations). Most locations rarely exceeded 16% moisture content for more than a few months. Certain moisture-trapping details consistently showed higher moisture levels (i.e., above 16%) and poorer drying. Some interior plies continued to show slow increases in MC even after months of drying conditions. These observations suggest preventative approaches implementable in the design (e.g., avoiding moisture trapping details), during fabrication (e.g., localized coating), and construction (e.g., sequencing installation to minimize exposure and allow drying). Full article

A wide diffusion of green envelopes in cities can be an opportunity to improve urban environment conditions and reduce negative effects of climate change. The green roof system is a widespread solution adopted all over the world due to the relative simplicity of installation and the large private and social benefits provided. Despite this, some factors hinder the diffusion of the green roof system, not only economic factors (due to the higher installation costs compare to a traditional roof solution), but also technical factors connected to lack of knowledge. The present paper investigates the factors influencing designers in the choice of a building roof systems, comparing a traditional solution and a greening system. The involvement of architects, engineers, and researchers allows the selection of the most important factors. Results of the study identifies their priority, and through a sustainability-based multicriteria analysis, the role played by each one in the decision process. This approach provides interesting hints to identify effective strategies to support a wider diffusion of greening systems for urban resilience. Full article

The estimation of direct and indirect losses due to earthquakes is a key issue in the Performance Based Earthquake Engineering framework. In commonly adopted loss computation tools, no specific data related to masonry infill panels, widespread in moment-resisting-frame residential buildings, are available to perform a probabilistic assessment of losses. To fill this gap, specific fragility and loss functions have been recently proposed in the last years. To assess their validity and estimate the relevance of the repair costs due to infills after earthquakes with respect to the total reconstruction process, the present work analyses the Reinforced Concrete residential buildings with masonry infills struck by the 2009 L’Aquila (Italy) earthquake, focusing on the dataset of “lightly” damaged buildings, where only damage to masonry infills occurred. Based on available data related to these buildings, the observed damage scenario after L’Aquila earthquake is first obtained. The repair costs for infills are estimated given this damage scenario. The resulting estimated repair costs are then compared with the actual repair costs presented in the available literature. The percentage influence of infills on the total repair costs due to earthquakes for residential buildings is lastly computed, resulting on average equal to the fifty percent. Full article

The information and communication technologies (ICTs) utilization ratio in the construction industry is relatively low. This industry is characterized by low productivity, time and cost overruns in projectsdue to inefficient management processes, poor communication and low process automation. To improve construction performance, a BIM-based (BIM - (Building Information Modelling) and augmented reality (AR) application (referred to as the AR4C: Augmented Reality for Construction) is proposed, which integrates a location-based management system (LBMS). The application provides context-specific information on construction projects and tasks, as well as key performance indicators on the progress and performance of construction tasks. The construction projects are superimposed onto the real world, while a site manager is walking through the construction site. This paper describes the most important methods and technologies, which are needed to develop the AR4C application. In particular, the data exchange between BIM software and the Unity environment is discussed, as well as the integration of LBMS into BIM software and the AR4C application. Finally, the implemented and planned functionalities are argued. The AR4C application prototype was tested in a laboratory environment and produced positive feedback. Since the application addresses construction sites, a validation in semi-real scenarios with end users is recommended. Full article

Most of the school buildings in Italy are high energy-demanding buildings with no ad-hoc ventilation systems (i.e., naturally-ventilated buildings). Therefore, reducing the heat losses of schools represent the main aspect to be dealt with. Nonetheless, the indoor air quality of the building should be simultaneously considered. Indeed, to date, energy consumptions and air quality are considered as incompatible aspects especially in naturally-ventilated buildings. The aim of the present paper is to evaluate the effect of different ventilation and airing strategies on both indoor air quality and energy consumptions in high energy-demanding naturally-ventilated classrooms. To this purpose, an Italian test-classroom, characterized in terms of air permeability and thermophysical parameters of the envelope, was investigated by means of experimental analyses and simulations through CO₂ mass balance equation during the heating season. The air quality was assessed in terms of indoor CO₂ concentrations whereas the energy consumptions were evaluated through the asset rating approach. Results clearly report that not adequate indoor CO₂ concentrations are measured in the classroom for free-running ventilation scenarios even in low densely populated conditions (2.2 m² person⁻¹), whereas scheduled airing procedures can reduce the indoor CO₂ levels at the cost of higher energy need for ventilation. In particular, when airing periods leading to the air exchange rate required by standards are adopted, the CO₂ concentration can decrease to values lower than 1000 ppm, but the ventilation losses increase up to 36% of the overall energy need for space heating of the classroom. On the contrary, when the same air exchange rate is applied through mechanical ventilation systems equipped with heat recovery units, the ventilation energy loss contribution decreases to 5% and the overall energy saving results higher than 30%. Such energy-saving was found even higher for occupancy scenarios characterized by more densely populated conditions of the classroom typically occurring in Italian classrooms. Full article

Construction customers want more complex facilities delivered faster and at a lower cost. Transaction costs account for a significant proportion of each new or refurbished facility (a 2017 report from the Infrastructure Client Group in the UK suggests as high as 50%), yet they contribute no value to the customer. Blockchain is being suggested as a way to reduce transaction costs by eliminating the need for intermediaries to build trust as a prerequisite for successfully executed agreements. This study first describes the thinking that underpins blockchain technology, outlining how it works, and the potential limitations of the technology. Second, using a case study, reviews the potential cost savings from the use of blockchain for a real estate company. The results reveal a potential cost savings from blockchain deployment at 8.3% of the total cost of residential construction, with a standard deviation of 1.26%. Third, we explore the implications, risks and applications of blockchain technology for improving flow in the end-to-end design and construction process and we identify opportunities for future research on blockchain applications in construction. Full article

Occupational safety in the construction industry still represents a relevant problem at a global level. In fact, the complexity of working activities in this sector requires a comprehensive approach that goes beyond normative compliance to guarantee safer working conditions. In particular, empirical research on the factors influencing the unsafe behavior of workers needs to be augmented. Thus, the relationship between human factors and safety management issues following a bottom-up approach was investigated. In particular, an easy-to-use procedure that can be used to better address workers’ safety needs augmenting the company’s safety climate and supporting safety management issues was developed. Such an approach, based on the assessment of human reliability factors, was verified in a real case study concerning the users of concrete mixer trucks. The results showed that the majority of human failures were action and retrieval errors, underlining the importance of theoretical and practical training programs as a means to improve safety behavior. In such a context, information and communication activities also resulted beneficially to augment the company’s safety climate. The proposed approach, despite its qualitative nature, allows a clearer understanding of workers’ perceptions of hazards and their risk-taking behavior, providing practical cues to monitor and improve the behavioral aspects of safety climate. Hence, these first results can contribute to augmenting safety knowledge in the construction industry, providing a basis for further investigations on the causalities related to human performances, which are considered a key element in the prevention of accidents. Full article

Timber folded surface structures assembled using semi-rigid multiple tab and slot joints (MTSJ) have been shown to form feasible structural systems with high load bearing potential. However, for their further development and use on large building scales, a pertinent model for prediction of their structural behaviour has yet to be developed. This paper focuses on simplified numerical methods for accurately modelling the semi-rigid structural behaviour of bidirectional timber folded surface structures with multiple tab and slot connections. Within this scope, the structure behaviour is considered to be in the elastic stage. Three practical methods of analysis for such structural systems are presented. The first two approaches use the Finite Element Method (FEM), where the theory of plates and shells are applied. In the first method, the MTSJs are modeled using strip element models, while, in the second strategy, spring models are used. The third modeling strategy elaborates on the new macroscopic mechanical models, referred to as macro models. Sets of one-dimensional (1D) elements are used to represent the mechanical behaviour of the entire system. Both linear and geometric nonlinear analysis are performed for all three modeling strategies. The numerical results are then validated against the large scale experiments. Comparison of the strip and spring element model results have shown that the strips represent more accurately the experimentally obtained values. Concerning the macro modelling approach, very good agreement with both detailed FE modelling approaches, as well as experimental results, were obtained. The results indicate that both linear and nonlinear analysis can be used for modelling the displacements within the elastic range. However, it is essential to include geometric nonlinearities in the analysis for accurate modelling of occurring strains as well as for displacements when considering higher load levels. Finally, it is demonstrated that including semi-rigidity in the numerical models is of high importance for analysing the behaviour of timber folded surface structures with MTSJ. Full article

Discrete element models are a powerful tool for the analysis of masonry, given their ability to represent the discontinuous nature of these structures, and to simulate the most common deformation and failure modes. In particular, discrete elements allow the assessment of the seismic behavior of masonry construction, using either pushover analysis or time domain dynamic analysis. The fundamental concepts of discrete elements are concisely presented, stressing the issues related to masonry modeling. Methods for generation of block models are discussed, with some examples for the case of irregular stone masonry walls. A discrete element analysis of a shaking table test performed on a traditional stone masonry house is discussed, as a demonstration of the capabilities of these models. Practical application issues are examined, namely the computational requirements for dynamic analysis. Full article

The structure of Tvrđa and its buildings date back to the Middle Ages. Tvrđa represents the Old Town of the city of Osijek and the best-preserved and largest ensemble of Baroque buildings in Croatia. After the withdrawal of the Ottomans in 1687, during the 18th century, the Austro-Hungarian administration systematically formed a new fortification system, regulated streets and squares and built a large number of military objects. Tvrđa took its present form in the 19th century and has kept it since then. Investigating the historical development of individual buildings, in addition to archival sources and existing architectural documentation, the obvious source of information are the buildings themselves. The aim of this paper is to explore the possibilities of using infrared thermography to find structural elements and hidden openings in historic buildings in Osijek’s Tvrđa. This paper describes the exploration of the 18th century openings on the facades of the former Kostić houses. The facades were bricked into the walls in the 19th century because houses were reused and their purposes changed from commercial to residential. Infrared thermography is often a starting, nondestructive testing method (NDT) for building analyses. This paper presents thermographic analyses of two buildings. The analyses were carried out in December 2017 and January 2018. Using a steady-state thermographic analysis of a building envelope as the first step, the audit was continued with step heating (SH) of an interest point where changes in a thermal pattern were expected due to additional bricking. Heat flux was generated by the usage of a heat gun for paint removal. Full article

Buildings with spatially complex interiors poise unique challenges during operations and maintenance. A complex interior makes wayfinding difficult, which can inhibit daily occupants from finding their desired location. Additionally, it can hamper emergency responders and evacuations during extreme emergency events. An experiment was conducted to analyze the effects of different information formats and spatial cognition on individual wayfinding in unknown environments. Participants were asked to memorize either a set of two-dimensional (2D) drawings or a three-dimensional (3D) model before navigating through a series of checkpoints in an unfamiliar environment. Individual wayfinding is dependent on an individual’s use of route knowledge or survey knowledge. Route knowledge was assessed from the start of the route to Checkpoint A (i.e., the first checkpoint). Meanwhile, survey knowledge was assessed from Checkpoint A to Checkpoint B. Spatial cognition of participants was measured by administering the card rotation and cube comparison tests. The research found that 3D models have a beneficial impact on the success of individual wayfinding. Furthermore, the success rate of the participants with a low spatial cognition improved significantly when using a 3D model rather than a set of 2D drawings. However, the success rates of participants with a high spatial cognition were not affected by the format of information. While the above results are significant, more experimentation is needed to confirm whether 3D information does effectively lower cognitive demand. Full article

The proposed study aims at analysing a sub-urban sector in the historic centre of Qualiano, located in the province of Naples (Italy), in order to assess the seismic vulnerability of the main typology classes (masonry and reinforced concrete) in the study area and the consequent expected damage scenarios. The typological and structural characterisation of the investigated area is done through the CARTIS form developed by the PLINIVS research centre together with the Italian Civil Protection Department. Subsequently, the vulnerability simulation analysis is carried out by means of a quick methodology integrated into a GIS tool in order to identify the structural units (S.U.) most susceptible at damage under seismic events. Furthermore, in order to take into account the possible damage scenarios, a parametric analysis is performed using a seismic attenuation law in order to obtain the maximization of the expected urban losses. Finally, the site and topographical local conditions, which negatively influence the severity of the seismic damage on the structures, have been taken into account in order to more correctly foresee the expected damage of the inspected sub-urban sector to be used for appropriate seismic risk mitigation plans. Full article

Millions of tonnes of leftover biosolids are increasingly stockpiled every year around the globe. Biosolids are a product of the wastewater sludge treatment process. Stockpiles necessitate the use of large areas of increasingly valuable land. Biosolids have many beneficial uses and are currently utilised in agricultural and land rehabilitation applications. However, it is estimated that 30% of biosolids are unused and stockpiled. A second and seemingly unrelated environmental issue is the massive excavation of virgin soil for brick production. The annual production of 1500 billion bricks globally requires over 3.13 billion cubic metres of clay soil—equivalent to over 1000 soccer fields dug 440 m deep or to a depth greater than three times the height of the Sydney Harbour Bridge. This paper investigates and proposes a practical solution for the utilisation of the world’s excess biosolids in fired–clay bricks. The physical, chemical and mechanical properties of fired–clay bricks incorporating 25%, 20%, 15% and 10% biosolids have been tested. Bricks were produced from three different biosolids samples collected at Melbourne’s Eastern Treatment Plant (ETP 22) and the Western Treatment Plant (WTP 10 & WTP 17–29). Compressive strength testing indicated results ranging between 35.5 MPa and 12.04 MPa for the biosolids-amended bricks. Leachate analysis was conducted on the bricks before and after firing, and the results demonstrate that between 43 and 99% of the heavy metals tested were immobilised inside the fired bricks compared to the heavy metals tested in the raw mixture. All leachate concentrations were found to be insignificant for the biosolids-incorporated bricks tested in this study. Biosolids can have significantly different chemical characteristics depending on the origin of the wastewater and the treatment procedure. Suitable leachate analysis should be undertaken on biosolids and test bricks before large-scale production is approved. Scanning Electron Microscopy (SEM) images illustrate that biosolids-amended bricks have a higher porosity than the control bricks, which corresponds to the lower thermal conductivity values recorded for biosolids-amended bricks. In addition, brick firing energy demands are estimated to decrease by up to 48.6% for bricks incorporating 25% WTP 17–29 biosolids due to the higher organic content of the mixture containing biosolids. The emissions study and comparative Life Cycle Assessment results show that the incorporation of biosolids into bricks is a positive and sustainable alternative approach with respect to all environmental impacts arising from the stockpiling of biosolids and brick manufacturing. Based on the results found in this comprehensive study, this paper proposes the inclusion of a minimum of 15% biosolids content into 15% of brick production in order to completely recycle all the approximately 5 million tonnes of annual leftover biosolids production in Australia, New Zealand, the EU, the USA and Canada. This is a practical and sustainable proposal for recycling all the leftover biosolids worldwide. Utilisation of only 15% of biosolids in brick production would reduce the carbon footprint of brick manufacturing whilst satisfying all the environmental and engineering requirements for bricks. Full article

Given a series of intrinsic features of structural glass systems (i.e., material properties, type of restraints, operational conditions, etc.), special care should be spent at the design stage, to ensure appropriate fail-safe requirements, but also in the service life of these innovative building components and assemblies. In this paper, the dynamic characterization of simple monolithic glass elements is presented, based on non-destructive laboratory experiments and Operational Modal Analysis (OMA) techniques, including Finite Element (FE) numerical simulations, classical analytical models, and video-tracking approaches. It is shown, in particular, how the actual restraint condition (i.e., flexibility of supports, with respect to ideal boundaries) can affect the vibration parameters of a given glass member (frequency and damping capacity). This turns out in possible variations of its overall structural performance, including stress-strain-related effects, hence suggesting the need for even further dedicated studies and methods for the reliable analysis and design of structural glass assemblies and complex systems under dynamic loads. Full article

The environmental performance assessment of the building and construction sector has been in discussion due to the increasing demand of facilities and its impact on the environment. The life cycle studies carried out over the last decade have mostly used an approximate life span of a building without considering the building component replacement requirements and their service life. This limitation results in unreliable outcomes and a huge volume of materials going to landfill. This study was performed to develop a relationship between the service life of a building and building components, and their impact on environmental performance. Twelve building combinations were modelled by considering two types of roof frames, two types of wall and three types of footings. A reference building of a 50-year service life was used in comparisons. Firstly, the service life of the building and building components and the replacement intervals of building components during active service life were estimated. The environmental life cycle assessment (ELCA) was carried out for all the buildings and results are presented on a yearly basis in order to study the impact of service life. The region-specific impact categories of cumulative energy demand, greenhouse gas emissions, water consumption and land use are used to assess the environmental performance of buildings. The analysis shows that the environmental performance of buildings is affected by the service life of a building and the replacement intervals of building components. Full article