Buildings

In the context of global climate change, the low-carbon city pilot policy has become an important strategy to promote green development. Based on the panel data from 257 prefecture-level and above cities in China, this study utilized the Super-Efficiency SBM (Slacks-Based Measure) to measure the land green use efficiency and analyzes the impact of the policy on adjacent non-pilot cities using a difference-in-differences model. The findings indicate that the implementation of low-carbon pilot policies can significantly improve the land green use efficiency in adjacent non-pilot cities, which can be primarily ascribed to the spillover effect and catfish effect. A heterogeneity analysis further revealed the positive effects of the policies in the eastern region and non-resource-based cities. This study provides valuable references for relevant legal provisions on environmental regulation and for continuously monitoring and evaluating the policy effects to achieve sustainable development goals. Full article

Promoting safe behaviors among construction workers and mitigating unsafe behaviors is an effective approach to enhancing safety performance in the construction industry. Although progress has been made, the research themes concerning construction workers’ safety-related behaviors (CWSRB) and the detailed progress of each theme remain unclear due to differences in review perspectives and conceptual scopes. This study utilized CiteSpace software (V6.2R3 version) to conduct an analysis of co-authorship networks, co-word networks, and co-citations on 563 published articles in this field from 2013 to 2023. This study’s outcomes highlight several key insights: (1) journals such as Safety Science play a pivotal role in the domain; (2) institutions such as the City University of Hong Kong and Hong Kong Polytechnic University, along with prolific authors like Li, are major contributors to the field; (3) the focus of research has evolved from early organizational factors towards a more diverse range of topics, with deep learning emerging as a significant current research hotspot; (4) this study has identified high-cited literature and 11 primary clusters within the field. Current research focuses on five areas: safety-related behavior concepts, influencing factors and consequences, formation mechanisms, interventions, and applications of new technologies. Establishing clear classification criteria for unsafe behaviors, comprehensively understanding the formation mechanisms of safety-related behaviors, evaluating the effectiveness of intervention strategies, and exploring the practical applications of new technologies are future research directions. This study provides researchers with a holistic view of the present state of research and potential avenues for future exploration, thereby deepening the knowledge and comprehension of stakeholders within this domain. Full article

Phase change thermal energy storage (PCTES) technology has garnered significant attention in addressing thermal management challenges in building HVAC systems. However, the cooling performance of PCTES systems in humid scenarios remains unexplored, which is crucial in subtropical regions, high-humidity underground areas, and densely populated spaces. Taking the mine refuge chamber (MRC) as an example, this study focuses on a passive temperature and humidity control system by employing cold storage phase change plates (PCPs) for 96 h. First, an improved and simplified full-scale numerical model including PCPs and MRC parts is established. Then, the model is validated through the experimental results and solved using a numerical method. Finally, the influence of various factors within the system is investigated and an optimization method involving batch operation is proposed. The results indicate that (1) within 40 h, the use of cold storage PCPs leads to an indoor temperature reduction of 4.8 °C and a 7% decrease in relative humidity; (2) the PCPs show asynchronous states in sensible and latent heat transfer rates; (3) for every 50 additional PCPs, the average indoor temperature increases by 0.6 °C and the relative humidity decreases by 1.5%; (4) implementing batch operation of PCPs ensures that the indoor Heat Index drops by 10 °C, which is vital for human survival. The findings will play a crucial role in the global expansion and application (including geographical and functional aspects) of phase change thermal storage technology. Full article

The Public–Private Partnership (PPP) model has significantly contributed to global infrastructure and public service provision. The evolution of the PPP model closely aligns with policy directives. China’s PPP policy evolution has included five stages: budding (1986–2000), fluctuating (2001–2008), steady (2009–2012), expanding (2013–2018), and stagnating (2019–present). This study employs bibliometric analysis and co-word analysis to examine 407 policies enacted by the Chinese government from 1986 to 2018. By extracting policy text keywords at various stages and constructing a co-word network matrix, this study delineates the distinctive characteristics of Chinese PPP policies across different epochs. It can be found that critical areas such as “government credit”, “contract spirit”, and “power supervision” are still underappreciated. The challenges confronting China’s PPP model are multifaceted, stemming from policy gaps that have led to substantial project difficulties. Although the government proposed a new mechanism for franchising in 2023, the new mechanism is only for new PPP projects, and the difficulties of existing PPP projects have not been solved. This study advocates for enhancements in project bankability, regulatory clarity, institutional environment improvement, contract spirit defense, and the development of the PPP-REITs model to address these issues. Full article

Maintaining the airtightness of building envelopes is critical to the energy efficiency of buildings, yet leak detection remains a significant challenge, particularly during building refurbishment. This study addresses the effectiveness of the acoustic beamforming measurement method in identifying leaks in building envelopes. For this reason, an in-field study employing the acoustic beamforming measurement method was conducted. The study involved testing over 30 rooms across three different multi-story office buildings of varying ages and heterogeneous envelope structures. Numerous leaks were located in the façades, which were subsequently visually confirmed or even verified with smoke sticks. The data, captured using an acoustic camera (a microphone ring array), revealed distinct spectra that indicate the method’s potential for further research. The basic functionality and the significant potential of this methodology for localizing leakages in large buildings were proven. Full article

Non-structural members, such as roofs and ceilings, become affixed to main beams that are known as structural members. When such main beams experience bending or compressive forces that lead to lateral buckling, non-structural members may act to restrain the resulting lateral buckling deformation. Nevertheless, neither Japanese nor European guidelines advocate for the utilization of non-structural members as lateral buckling stiffeners for beams. Additionally, local buckling ensues near the bolt apertures in the beam–roof folded plate connection due to the torsional deformation induced by the lateral buckling of the H beam, thereby reducing the rotational stiffness of the roof folded plate to a percentage of its ideal stiffness. This paper conducts torsional experiments on roof folded plates, and with various connection methods between these plates and the beams, to comprehend the deformation mechanism of roof folded plates and the relationship between their rotational stiffness and the torsional moment. Then, the relationship between the demand values against restraining the lateral buckling of the main beam and the experimentally determined bearing capacity of the roof folded plate is elucidated. Results indicate the efficacy of utilizing the roof folded plate as a continuous brace. The lateral buckling design capacity of H beams that are continuously stiffened by roof folded plates is elucidated via application of a connection method that ensures joint stiffness between the roof folded plate and the beam while using Japanese and European design codes. Full article

Thermochromic (TC) smart windows are a leading passive building design strategy. Vanadium dioxide (VO₂), hydrogel and TC-Perovskite glazing, which constitute the main categories of TC materials, modulate different wavelength regions. Although numerous studies have reported on these TC glazings’ energy-saving potential individually, there is a lack of data comparing their energy efficiencies. Moreover, their suitability as an alternative to dynamic solar shading mechanisms remains unexplored. Using building energy simulation, this study found that a hydrogel glazing with broadband thermochromism can save more energy (22–24% savings on average) than opaque roller shades (19–20%) in a typical office in both New York and Hong Kong. VO₂ glazing performed comparably to translucent roller shades (14–16% savings), except when used in poorly daylit conditions. TC-Perovskite was a poor replacement for roller shades (~2% savings). The window-to-wall ratio (WWR) that allowed both energy savings and optimal natural light penetration was also identified for each glazing. Hydrogel glazing demonstrated both energy and daylight efficiency in Hong Kong’s cooling-dominated climate when used in 40–50% WWR configurations. In New York’s colder conditions, VO₂ glazing did so for higher WWRs (50–70%). Roller shades could also achieve simultaneous energy savings and visual comfort, but only for highly glazed facades (up to 80%). Full article

This study aimed to discuss the influence of specimen sizes on the compressive strength parameters of wood, specifically focusing on their compression strength, elastic modulus, and Poisson’s ratio. Therefore, three different-sized specimens (20 mm × 20 mm × 30 mm, 40 mm × 40 mm × 60 mm, 60 mm × 90 mm × 90 mm) were manufactured and tested in the longitudinal, radial, and tangential directions, following the standard testing method for acquiring the compressive strength of wood. Subsequently, based on the experimental results, compressive parameters, failure mechanisms, load–displacement curves, and stress–strain relationships were systematically analyzed for the three different-sized specimens. Meanwhile, the influence of specimen size on the compressive strength parameters of wood was also evaluated through finite element numerical simulations, utilizing the obtained mechanical parameters. The results revealed a significant correlation between compressive strength and specimen size, indicating a decrease in compressive strength with an increasing specimen size. Conversely, the elastic modulus and Poisson’s ratio exhibited less sensitivity to specimen size changes. Notably, the compressive strength parameters derived from small-sized specimens (20 mm × 20 mm × 30 mm) exhibited a lack of rationality, while those obtained from medium-sized (40 mm × 40 mm × 60 mm), and large-sized specimens (60 mm × 90 mm × 90 mm) demonstrated greater reliability, providing precise results in finite element numerical simulations. Full article

This paper reports a novel investigation in applying commercial Ultra High-Frequency RFID tags (UHF-RFID tags), which are widely used in logistics as sensing elements in civil engineering structures, particularly for monitoring out-of-plane displacements of brick masonry walls. Both laboratory tests and in situ experimental tests assessed the feasibility of the proposed application. Laboratory tests showed a very satisfactory response while the in situ experiments showed a weaker response. Nevertheless, the potential reliability of the proposed technique can be stated. The authors traced back the causes of the performance decrease to environmental interference, mainly due to the extensive presence of a rigid steel frame surrounding the out-of-plane loaded panels. Measurements of displacements, in fact, are obtained indirectly from the phase of UHF-RFID signals that strongly suffer from multipath generated by metallic surfaces. Despite some limitations, the proposed measurement technique permits a reliable and sustainable approach to the monitoring of structures. The use of commercial UHF-RFID wireless tags, in fact, assures easy and fast installation operations and assures the possibility of placing a large number of sensors over the structure with very low maintenance costs with respect to the more traditional monitoring techniques. Moreover, using very thin and small commercial UHR-RFID tags on cultural heritage structures can represent an opportunity for sustainable long-time monitoring with reduced costs. Overall, the results of this study are sufficiently satisfactory to be considered as the opening of new possible scenarios in wireless structural monitoring in the civil engineering field. The authors propose as future work to use UHF-RFID tags for the real-time monitoring of an existing masonry facade that, not being characterized by the presence of a steel frame, can potentially assure an adequate response and properly transmit the electromagnetic signal. Full article

This study proposes a form of concrete-filled steel tube column with a multiple-chamber round-ended cross-section (M-CFST). Longitudinal and transverse stiffening ribs divide the circular-ended section into different chambers, strengthening the steel tube’s confinement effect on the core concrete and improving the component’s seismic performance. A three-dimensional finite element (FE) solid model of the M-CFST is created by employing the FE software ABAQUS. Quasi-static analysis is conducted to investigate the influence of parameters, such as chamber arrangement, aspect ratio, and axial compression ratio, on flexural hysteresis performance. Moreover, the failure modes, hysteresis curves, skeleton curves, strain development, and energy dissipation of the components are analyzed. The results show the following: (1) The FE model presented in this study can simulate the quasi-static behavior of CFST columns accurately, and the calculated results are in good agreement with the measured values. (2) The seismic performance of the composite column is excellent, with a large number of chambers leading to a robust hysteresis curve for the composite columns, resulting in increased bearing capacity and energy dissipation capacity. However, the energy dissipation performance of the specimen with a two-chamber arrangement is slightly lower than that with a single-chamber arrangement. (3) The results of the finite element analysis suggest that the long and short sides of the CFST columns with a large length–width ratio should be arranged to be relatively close in length. Full article

Industry 5.0 is expected to solve the issue of job insecurity and reluctance to adopt emerging technologies in Industry 4.0 through increased workforce participation. To achieve that, proactive training should be afforded to enable the workforce to co-work with new technologies. Drones are an emerging technology increasingly adopted in construction, which has enormous data collection and safety implications when operational skills are inadequate. Yet, current drone training programs appear to be generic, and their ability to equip operators for flying tasks is questioned. This study aims to answer this question by assessing the adequacy of existing drone training programs and proposing training needs and strategies for drone operators in the construction industry. Data collected using semi-structured interviews from 22 purposively selected respondents in Hong Kong and desk research of websites were subjected to inductive content and thematic analysis using MAXQDA Analytics Pro 2022 software and narrative review. It was deduced that drone training courses in Hong Kong were mostly generic (UAS Pilot Training—Level 1, FPV operation). Interviewees considered existing drone training/training courses as inadequate for four reasons, including “lack of context-fitting considerations”, “incompetence of drone operators”, and “lack of demand/interest”. Regarding the need for specialized drone training courses, two barriers and two training ecosystem themes emerged, with the high cost of specialized courses being a potential barrier to adoption since they could hamper enrolment. The training ecosystem themes were consistent with the “the training is inadequate” theme. This study proposes two drone operation training strategies: “competence-based training” and a “train-the-trainer” model. Drone training courses or programs under each training strategy should include (i) training content such as “safety training” and off-GPS training and (ii) knowledge and skill maintenance measures such as mandatory continuous professional development and retraining techniques. The proposed training strategies will equip operators to work efficiently and safely with drones. The study offers valuable references for training organizations and government authorities. Full article

This study presents an updated view of the effects of the 1940 Vrancea earthquake. Recently compiled studies in the literature from the time of the event, as well as other studies, present the opportunity to gain additional and relevant information regarding this large-magnitude event. The effects of this earthquake on various locations in Romania are compared to those observed after the subsequent large Vrancea earthquake of 1977. An assessment of the economic losses caused by the seismic event is also attempted. The seismic vulnerability of some building typologies commonly used before 1940 is assessed by employing the earthquake damage data and the well-known macroseismic method. The impact of this event on the design and construction practices in Romania is evaluated using the collected information as well. Finally, the policy of repair and strengthening of buildings applied after the event is also discussed, and case studies are presented. Full article

Construction professionals work in silos and use traditional design and construction methods. The growing demand for rapidly built and high-quality construction is making off-site manufacturing mainstream. Studies have shown that collaboration among all stakeholders is a necessary component for success in the construction of such buildings. This multidisciplinary study of an existing concrete hotel aims to explore an alternative structural design in mass timber or volumetric modular construction. To this end, the reinforced concrete floor plan of Club Med de Charlevoix in Quebec, Canada, was used as a benchmark for two different structural systems. The first strategy investigated CLT (cross-laminated timber) and glulam columns to replicate the reinforced concrete system (column–slab), while the second involved maximum prefabrication (volumetric modular construction). Both mass timber and volumetric modular strategies can lead to a smaller carbon footprint. The main conclusion is that the plan should be designed from the outset to be either traditional or prefabricated since major changes are required if the choice is made to switch from one system to the other. Moreover, when structural systems maximize off-site construction, such as volumetric modular construction, the various professions need to be included during early planning. This is necessary to avoid task duplication and prevent the neglect of considerations such as manufacturable dimensions and partition organization. Full article

Road structures undergo a series of chemical and physical processes once they are put into service. This phenomenon results from the action of the load and the influence of the environment, which causes their progressive deterioration. In order to mitigate the risk of progressive deterioration and guarantee their stability and durability, various maintenance tasks are required, including visual inspections. The Intelligent Bridge Management System of Colombia (SIGP) includes visual inspection as one of its modules. The system has been designed based on state-of-the-art criteria and national experience with relevant damages and bridge collapses. This paper presents the visual inspection methodology, which includes several stages such as a classification scale, condition index, evaluation areas, damage catalog, and evaluation criteria. In addition, a digital application has been developed to facilitate real-time data collection during field inspections using mobile devices, which can be uploaded directly to the system database hosted in the cloud. The results from the inspection of bridges of different typologies and years of construction are presented, as well as general inspection results from 150 bridges in Colombia. The relevance, comprehensiveness, and accuracy of the inspection are supported by a damage catalog, which allows the identification of intervention needs and reduces the bias of the collected data. Full article

The intensive use of air conditioning systems, primarily refrigerating, to promote thermal comfort in countries such as Brazil (a hot climate country) is changing the electrical energy consumption patterns and peak demand. Even with the increased number of appliances, we must learn to consume less energy to achieve similar outcomes with higher energy efficiency. Consequently, exergy analysis is used to evaluate the quality of these energy conversion systems. Four computational human thermal models were used to assess thermal comfort conditions: one man wearing lighter clothing, one man wearing traditional office clothing, and two women in the two types of clothing. We chose these four models since the body composition and basal metabolism rates for males and females differ. In addition, the insulation of clothes influences the temperature of the thermal environment, leading to a significantly lower percentage of people being unsatisfied, from 12.8% to values close to 5%. The outputs of these occupants are used as inputs for a computational model of the room to calculate its associated thermal loads and evaluate different temperature setpoints and their effects on thermal comfort and energy consumption. Results indicate that environmental temperatures above 24 ${}^{\circ }$C and below 26 ${}^{\circ }$C may lead to thermal comfort conditions, depending on the occupants’ clothing. Clothing would represent a thermal resistance of 0.7 CLO for men and women (when in the luteal phase of the menstrual cycle) and 0.8 CLO for women in the follicular phase when the environment is at 25 ${}^{\circ }$C. Therefore, there is a significant reduction in the compression power of the central cooling system by about 2.2% compared to 24 ${}^{\circ }$C and around 8% compared to ambient temperatures around 21 ${}^{\circ }$C. Full article

With the development of urbanization, more and more construction and demolition waste (CDW) is generated. To enhance the mechanical properties and durability of concrete through the incorporation of recycled aggregate, the water/cement ratio was controlled to optimize the properties of concrete. In this work, one reference concrete with a water/cement ratio of 0.5 was prepared. The demolition concrete waste from East China was used, and 50% and 100% of the natural aggregates of the reference concrete were substituted. Furthermore, the water/cement ratio of concrete with 50% and 100% CDW was reduced to 0.3, and the superplasticizer was used to justify the workability of fresh concrete. Finally, the workability of fresh concrete was determined. After curing for 28 days, the density, water absorption, and resistance to chloride penetration of concrete were realized. The compressive and flexural strength were examined at 14 and 28 days, and the electrical resistivity test was conducted at 7, 14, and 28 days. The results indicate that with increasing CDW content, the mechanical properties and durability of concrete decreased. However, when the water/cement ratio decreased to 0.3, the concrete properties were optimized, such as the compressive strength and resistance to chloride penetration of concrete with 50% CDW increased by 74.2% and 28%, respectively. Full article

The study presented an approach to accomplish the nearly zero-energy school building through the assessment of energy and economic performance of the design solutions with renewable energy systems. For energy use in the school building, the energy was mainly consumed by artificial lighting through the analysis of two years’ energy consumption. Available passive and active solutions were adopted to improve energy efficiency in the school building and the energy performance of each design solution was analyzed. To achieve the nearly zero-energy school building, the remaining energy was offset by solar PV panels. Comparing the payback time for design solutions with the PV systems, the most appropriate design solution was selected to achieve the nearly zero-energy school building design under mild climates. In sum, the present study has revealed the challenges of achieving nearly zero-energy school building design under the climate conditions in Saudi Arabia. Moreover, the outcome of the study can lead to the development of a nearly/net-zero-energy building design under hot climates. Full article

Poor wind conditions in metropolitan areas can result in inadequate ventilation and degradation of the thermal environment. Several researches have demonstrated that the building ground floor elevation (BGFE) enhances the wind conditions surrounding buildings. Further investigation is required to thoroughly examine the BGFE’s impact on the wind conditions in the courtyard area. We researched how the various overhead placements affect the ventilation of a U-shaped school building’s courtyard space in different wind directions. We performed Computational Fluid Dynamics (CFD) numerical simulation experiments on 93 overhead scenarios based on field measurements and validation. The statistical analysis of the experimental data revealed that the BGFE had significant effects on reducing the mean air age (p < 0.001), standard deviation of air age (p < 0.01), standard deviation of wind speed (p < 0.001), and mean wind speed (p < 0.01) in the courtyard space. The BGFE in the northeastern zone of the U-shaped school building significantly increased the mean air age (p < 0.05), while the BGFE in the middle and southwestern zones significantly decreased the mean air age (p < 0.001), and the BGFE in the southeastern zone significantly decreased the mean wind speed (p < 0.05). The BGFE facilitates the entry of fresh air and offers even ventilation while significantly reducing wind speed. Choose sites C and D to enhance the U-shaped courtyard’s ventilation and avoid locations B and E. This paper’s findings provide theoretical guidance for designing the elevation of courtyard space from a ventilation perspective and for the green rehabilitation of existing buildings. Full article

The aim of this paper is to evaluate the nonlinear static response of steel concentrically braced frames (CBFs) by considering the response of embedded footings in granular soils using the Beam on Nonlinear Winkler Foundation (BNWF) approach. To model the vertical stress-displacement behaviour of footings, it is possible to define a backbone curve capable of reproducing the total response by adding in series the behaviour of the compression zone with that of the tension zone. When uplift of the soil–foundation system is allowed, it has been demonstrated that it is necessary to consider the horizontal stresses of the native soil on site and the degree of compaction of the soil mass above the footing to avoid significant deviations between the analysis results and the real response. The tension zone in the backbone curves was calibrated while considering these parameters, and given the difficulty associated with their calibration, an estimation is reported that could also be used in the case of practical applications. The implementation of the model has been validated through various pushover analyses on an archetype steel CBF originally tested on a fixed base condition, and predictions were made for the flexible base condition, considering different types of soil and different embedment depths. The results suggest that there is a relationship between the nonlinear static response of steel CBF structures and the uplift mechanism of embedded footings that is influenced by the embedment depth of the footings and the shape of the tension-displacement zone of the backbone curves considered in the modelling process. The proposed model can be used to simulate the flexible base condition of CBF structures on embedded footings using nonlinear springs when carrying out performance-based design procedures. Full article