Buildings, Volume 13, Issue 2 (February 2023) – 308 articles

Rapid and accurate identification of moving load is crucial for bridge operation management and early warning of overload events. However, it is hard to obtain them rapidly via traditional machine learning methods, due to their massive model parameters and complex network structure. To this end, this paper proposes a novel method to perform moving loads identification using MobileNetV2 and transfer learning. Specifically, the dynamic responses of a vehicle–bridge interaction system are firstly transformed into a two-dimensional time-frequency image by continuous wavelet transform to construct the database. Secondly, a pre-trained MobileNetV2 model based on ImageNet is transferred to the moving load identification task by transfer learning strategy for describing the mapping relationship between structural response and these specified moving loads. Then, load identification can be performed through inputting bridge responses into the established relationship. Finally, the effectiveness of the method is verified by numerical simulation. The results show that it can accurately identify the vehicle weight, vehicle speed information, and presents excellent strong robustness. In addition, MobileNetV2 has faster identification speed and requires less computational resources than several traditional deep convolutional neural network models in moving load identification, which can provide a novel idea for the rapid identification of moving loads. Full article

Off-site construction (OSC) is an innovative construction method that transfers most of the site-based work to a more controlled environment. Construction waste minimization, speedy schedules, higher sustainability, and better quality are some of the perceived benefits of OSC. Therefore, significant research attention has been given to OSC. However, minimal research attention has been given to procurement management in OSC, which could impact its pace of adoption. Existing studies on the procurement methods of OSC projects have overlooked several criteria related to OSC that impact the selection of the appropriate procurement methods (i.e., design-build, construction management, etc.). In addition, the literature lacks decision-making tools to assist OSC practitioners in selecting the appropriate procurement method. In this regard, this study contributes to the body of knowledge by (1) identifying the criteria that impact the selection of OSC procurement methods; (2) developing a multi-criteria decision-making (MCDM) model to select the appropriate OSC procurement methods. The developed MCDM model uses a hybrid approach of analytic network process (ANP) and evidential reasoning (ER). The ANP, which considers the interdependencies among the collected OSC procurement criteria, is used to calculate the relative importance weights through questionnaire surveys. The ER method evaluates various OSC procurement methods in accordance with the criteria importance weights. The results indicate that project quality, cost control, and funding arrangement are the prominent selection factors. On the other hand, the model reveals that the integrated project delivery (IPD) and construction management (CM) methods have the highest utility scores. The MCDM model has been validated by comparing the results with similar studies. The present study could assist OSC practitioners in selecting the appropriate procurement method for OSC projects. Full article

The rapid development of the traditional ceramic industry contributes considerably to economic advancements; however, the ecological hazards caused by the large amount of sintered ceramic wastes generated during ceramic production and discarded at landfill sites are becoming increasingly severe. To realize the large-scale resource utilization of ceramic waste, sintered ceramic waste was used in this study to partially replace natural quartz sand, and new environmentally friendly artificial stones were fabricated by using vacuum vibration molding and inorganic/organic composite curing technology. The effects of ceramic waste addition and particle size on the mechanical strength, surface hardness, wear resistance, stain resistance, and microstructure of artificial stone materials were investigated. The results showed that the replacement of quartz sand with 40–55% ceramic waste significantly improved the mechanical strength of artificial stone and maintained sufficient surface hardness and wear resistance. When 45% of ceramic waste powder (particle size ≥ 120 mesh) was added, the bending strength of the artificial stone was 64.4 MPa, whereas when 55% of ceramic waste particles with different particle sizes were added, the maximum compressive strength was 158.7 MPa. Good wear resistance and sufficient Moh’s hardness of 5.5–6.5 was obtained for all the samples. The prepared ceramic waste artificial stone also had a dense microstructure and low water absorption and porosity, which are helpful for improving stain resistance. Full article

The current study depicts the effects of different insulation materials and fuel types on the cooling and heating performance of buildings situated in hot and dry, warm and humid, composite, and cold climatic conditions in India. Ten different locations chosen from diverse climatic regions were selected, and various potential parameters for expanded polystyrene and extruded polystyrene insulation materials were evaluated. Potential parameters, such as optimal insulation thickness, annual savings, and payback period, were computed for cooling and heating requirements and were found in the ranges of 0.0428–0.891 m, 10.83–19.19 $/m², and 1.49–2.36 years for cooling, as well as 0.0063–0.1522 m, 0.29–55.92 $/m², and 0.95–6.52 years for heating, respectively. An emission analysis was also carried out for the estimation of greenhouse gas (GHG) emissions by the engagement of optimal insulation thickness for heating. The GHG emissions from natural gas, coal, and diesel by the employment of various insulating materials were found in the ranges of 5.39–11.28, 9.47–32.68, and 2.26–4.51 kg/m²-year, respectively. A correlation formulation (power) for optimal insulation thickness was also carried out. For checking the preciseness of the developed mathematical models, statistical tools were utilized, and their obtained values in the satisfactory range signified the accurateness of the developed models. Full article

This study investigates the effect of the partial replacement of ordinary Portland cement (OPC) with cement kiln dust (CKD) on the engineering properties of pozzolanic concrete for use in block manufacturing. Ultimately, this could potentially reduce cement consumption and CO₂ emissions. The study was carried out on cylindrical concrete samples prepared from five mixtures comprising 71.13% pozzolan and 14.16% water, with 0, 5, 10, 15, or 20% of the OPC fraction (14.71 wt.%) replaced by CKD. The samples were tested for density and compressive strength (UCS) at curing ages of 7, 14, 28, 56, and 91 days; and for voids and water absorption after 28 curing days. Results show that increasing CKD content lowered the voids and increased the water absorption. The 15% CKD sample had the highest UCS, regardless of the curing age. X-ray diffraction analysis confirmed that the phase responsible for hydration, calcium silicate hydrate, was higher in the 15% CKD sample than the control. Full article

Occupancy, which refers to the occupant count in this paper, is one of the main factors affecting the energy consumption of commercial buildings. It is important for both building managers and energy simulation engineers to understand how an entire building’s energy consumption varies with different occupancy levels in the process of building automation systems or in assessments of building performance with benchmarking lines. Because commercial buildings usually have large scales, complex layouts and a large number of people, it is a challenge to simulate the relationships between an entire building’s energy consumption and occupancy. This study proposes a fast method for calculating the influence of occupancy on the energy consumption of commercial buildings with different building layouts and existing occupancies. Other occupant behaviors, such as the opening of windows and adjustment of shading devices, are comprehensively reflected in two basic building parameters: the balance point temperature and the total heat transmission coefficient of the building. This new method can be easily used to analyze how building energy varies with occupancy without a physical building’s energy model. An office building in Shanghai is taken as a case study to validate the proposed method. The results show that the coefficient of determination R² between the calculated value and actual value is 0.86, 0.8 and 0.71 for lighting, cooling and heating energy, respectively, which is suitable in engineering applications. Full article

The steel frame-reinforced concrete core tube structural system is widely used in mid-rise and high-rise buildings due to its good seismic behaviour and high construction efficiency. Since the steel frame and the reinforced concrete core tube are supposed to deform synergistically under earthquake action, the steel beam-concrete wall joint (SBCW joint for short) will be subjected to a significant pull-out force. Therefore, the pulling resistant capacity of the SBCW joint is quite important for the seismic performance of the overall structure. In response to the shortages of the existing SBCW joint types, a new SBCW joint with a T-stub connector was proposed and studied. The experimental and analytical research has indicated that there are different failure modes and force mechanisms of the SBCW joint under pull-out load, and further studies are required for the pulling resistant capacity. On the basis of recent research findings, a numerical investigation on the pulling resistant capacity of the joint is conducted in this study. An elaborate 3D finite element model of the SBCW joint is proposed, and the load performance, strain and stress development, deformation characteristics and failure modes are analysed in detail. Then, a series of parametric analyses are carried out based on the finite element model, indicating that the length and the web height of the T-stub connector, the number of shear studs on the connector and the reinforcement ratio of stirrups have an obvious effect on the pulling resistant capacity. Finally, the critical value of the embedded depth of the connector, which is found to be one of the most important parameters for the failure mode and pulling resistant capacity of the joint, is determined, and design recommendations are proposed for the SBCW joints with T-stub connectors. Full article

The reliability of concrete structures is closely related to the durability of the concrete materials stable under external environmental conditions. The present study is aimed at analysing the effect of a prospective hardening additive containing calcium alumoferrites and calcium sulfate (AFCS) as a substitute (5–15%) for Portland cement. The hardened cement pastes were characterized by water absorption, shrinkage, strength and corrosion resistance. It was shown that replacing a part of Portland cement with the AFCS additive results in an increase in the strength of fine-grained concrete and in the water resistance grade of concrete. The use of the AFCS additive in the mixed cements reduces the shrinkage of cement stone, resulting in shrinkage-free fine-grained concretes. The increased corrosion resistance of the hardened cement paste is caused by a chemical (saturation) equilibrium between corrosive medium and a cement stone. Penetration of sulphate ions from corrosive solution into the hardened cement paste is much lower, unlike Portland cement. Following saturation of the hardened cement paste with sulphate ions, their further penetration into the cement stone does not occur. Based on the results of the study, recommendations were developed for the use of the hardening alumoferrite-gypsum additive to Portland cement, which allows to improve the mechanical and corrosion characteristics of concrete. Full article

Most regional seismic damage assessment (RSDA) methods are based on the rigid-base assumption to ensure evaluating efficiency, while these practices introduce factual errors due to neglecting the soil–structure interaction (SSI). Predicting the influence of the SSI on seismic responses of regionwide structure portfolios remains a challenging undertaking, as it requires developing numerous high-fidelity, integrated models to capture the dynamic interplay and uncertainties in structures, foundations, and supporting soils. This study develops a one-dimensional convolutional neural network (1D-CNN) model to efficiently predict to what degree considering the SSI would change the inter-story drifts and base shear forces of RC frame buildings. An experimentally validated finite element model is developed to simulate the nonlinear seismic behavior of the building-foundation–soil system. Subsequently, a database comprising input data (i.e., structural and soil parameters, ground motions) and output predictors (i.e., changes in story drift and base shear) is constructed by simulating 1380 pairs of fixed-base versus soil-supported structures under earthquake loading. This large-scale dataset is used to train, test, and identify the optimal hyperparameters for the 1D-CNN model to quantify the demand differences in inter-story drifts and base shears due to the SSI. Results indicate the 1D-CNN model has a superior performance, and the absolute prediction errors of the SSI influence coefficients for the maximum base shear and inter-story drift are within 9.3% and 11.7% for 80% of cases in the testing set. The deep learning model can be conveniently applied to enhance the accuracy of the RSDA of RC buildings by updating their seismic responses where no SSI is considered. Full article

Based on a plain concrete pile composite foundation project in the coastal area of Zhuhai, considering the complex hydraulic load environment induced by tidal water-level changes, finite element simulations and parameter calibrations were carried out to determine the physical and mechanical properties of plain concrete pile composite foundation. The hardening soil small (HSS) model, which can be used to simulate the complex mechanical behavior of soft soil under small strain, was selected for modeling analysis. Model parameters were calibrated through resonance column tests, triaxial consolidation drainage loading and unloading shear tests. The complex hydraulic loads were analyzed, including the effects of cyclic tidal action and the sudden rise and fall of the water level induced by strong storm surges on the force, deformation of plain concrete piles, and the mechanical seepage properties of soft soil around piles. The results indicate that: (1) Compared with coastal soft soil in Shanghai, Zhoushan, Tianjin, and other areas, the soft soil in the Zhuhai area has a smaller dynamic shear modulus, cohesion and internal friction angle, and worse engineering properties. (2) The sudden rise of water level leads to a sudden change in the pore pressure of the groundwater, which induces a large deformation of the pile-soil composite foundation. If the foundation on the offshore (dike) side exhibits the most prominent deformation and foundation damage, such as uneven settlement is prone to occur. (3) The offshore side pile is most affected by the hydraulic loads. The deformation of the pile body along the pile body is uneven and the deformation of the upper pile body is relatively large, which may cause fracture damage. Full article

The structural and seismic fragility assessment of minor historical centers of the Inner Peripheries of Italy is a key phase of the preservation process of the historical and cultural features of a portion of the Italian building stock, whose reuse is crucial for the reversal of shrinking trends and the stimulation of population growth. In this framework, the opportunities offered by digital crowd-sourcing technologies with respect to performing probabilistic structural safety assessment at a large scale are investigated herein. The objective of this research was to exploit data and information available on the web such that the key building features of an area of interest are collected through virtual inspections, historical databases, maps, urban plans, etc. Thus, homogeneous clusters of buildings identified in the area of interest are catalogued and associated with specific building classes (chosen among those available in the literature), and the buildings’ levels of seismic fragility are determined through the development of fragility curves. The research outcomes show that the proposed approach provides a satisfactory initial screening of the seismic fragility level of an area, thus allowing for the identification of priority zones that require further investigations or structural interventions to mitigate seismic risk. Full article

Soil-nailing is a simple and economical method of stabilizing cut slopes and retaining excavation. Most of the soil-nailing related studies, in particular the experimental work, were conducted in idealized or homogeneous ground, but such a result might not necessarily be representative. Thus, for a more representative study, instead of treating the ground as homogeneous it should be treated as a system of horizontal layers. This study assessed the performance of a full-scale nailed retaining structure for a foundation pit of a 20-storey building through a series of numerical analyses. The influence of full-face facing thickness, nail head geometrical configuration (size and thickness) and surcharge loading on the response of the structural components of the soil-nailing system adopted is the main concern. The results were evaluated in terms of axial force, shear force and bending moment of the structural facing element and the horizontal displacement of the soil retained behind the facing element. In both cases, the distribution of nail axial (tensile) force in each nail reinforcement was also compared and evaluated. It was found that the thickness of full-face facing affected the facing shear force and bending moment, while the surcharge loading influenced the facing axial force and the horizontal displacement of the retained soil and that the magnitude of the axial force registered at the fixed end was governed by the size of the discrete nail head. Full article

Sensing performance is crucial for real-world applications of the embedded piezoelectric lead zirconate titanate (PZT) sensors in concrete structures. Based on the electromechanical impedances (EMIs) obtained numerically and experimentally from the embedded PZT sensors, effects of installation orientation and interfacial roughness were investigated on their sensitivity and reliability for quantitative concrete stress monitoring. The numerical results suggest a better sensitivity in the embedded 90° PZT sensors, with planar normal perpendicular to the loading direction, where the conductance amplitude variation is 6.5 times of that of the 0° PZT sensors, with normal parallel to load direction. Further, the improved reliability of the PZT sensors with rough interfaces is observed experimentally, which makes them robust for concrete stress monitoring over a wider sensing range from 0 to 20 MPa. Based on the static analyses, it is noted that the sensing performance of the embedded sensor is significantly affected by the interfacial stiffness degradation induced by the enhanced strain surrounding the sensor. These findings suggest that delaying the interfacial stiffness degradation, i.e., with proper installation orientation and interfacial treatment, could improve the sensing performance of the embedded sensors for quantitative concrete stress monitoring. Full article

It is hard to grasp the deformation law of the surrounding rock and the force characteristics of the support structure during the construction of ultra-small clearance tunnels in upper soil and lower rock composite strata. Based on the ultra-small clearance tunnel in Li Shuping, Tongxin Expressway, Guizhou, this paper adopted a combination of numerical simulation and field monitoring to analyze the influence of different burial depths and soil-rock interface positions on the deformation of the surrounding rock and the internal forces of the support structure of the ultra-small clearance tunnel. The conclusions are: (1) the monitoring data show that the stress in the steel frame of the leading tunnel increases first by the influence of proximity construction, and then decreases and reaches a stable value after the secondary lining is applied, and the stress at the arch waist of the soft soil layer furtherest from the side of the middle rock column is greater than that in the rock layer on the side of the middle rock column; (2) the position of the soil-rock interface has a significant influence on the initial support force of the first tunnel, and the bending moment of the structure increases with the downward movement of the soil-rock interface and the increase in the burial depth; (3) the influence of the soil-rock interface position on the initial support moment of the first tunnel is greater than the influence of proximity construction, a point to which attention should be paid during construction; and (4) when the soil-rock interface is located below the foot of the arch, the deformation of the surrounding rock of the following tunnel will be larger than that of the first tunnel. The results can provide a reference for the design and construction of ultra-small clearance tunnels in upper soil and lower rock composite soft strata and soil strata. Full article

Teaching production systems and Lean tools is a challenge for educators in the construction area, which is highlighted by the difficulty of emulating in the classroom the scenarios that industry professionals will face. Hence, implementing pedagogical games has a high potential to improve construction education processes. However, gaps are observed in the proposal of pedagogical games applicable to teaching construction systems based on Lean tools. Considering this gap, this paper proposes a game of paper planes to support the teaching of production systems in construction based on the Lean tools Continuous Improvement Cells and 5S. The research method consisted of applying the Design Science Research (DSR) method to develop, evaluate, and improve the game proposal. Thus, the game was assumed as an artifact subject to a development and improvement process to solve an identified problem. The proposed game consists of three main rounds: (1) production system design, (2) Continuous Improvement Cells implementation, and (3) 5S implementation. The main theoretical and practical contribution is the proposal of a pedagogical game to support the teaching of construction production systems based on Lean tools, evaluating students’ knowledge by applying surveys before and after the game and assessing performance indicators. The application of the game to a group of undergraduate and graduate students showed a broad positive impact on the assimilation of the principles of construction production systems based on Lean tools. Full article

Project Management Maturity Models (PMMM) are considered practical tools to deal with poor Project Management (PM) performance, an issue that concerns academics and practitioners. However, the models that exist are something close to “one size fits all”. This means that those models might not be suitable for activity sectors with specific requirements, such as construction, in particular, the renovation and remodelling construction firms. The present research proposes a PMMM to assess the PM capabilities of Portuguese renovation and remodelling Project-Based Firms (PBF). To achieve this goal, the authors developed documental research, followed by exploratory research through qualitative analysis. The researchers conducted semi-structured interviews and performed a content analysis of the fully transcribed interviews. Compared with the literature review’s findings, qualitative analysis results made it possible to find closure on previous research that indicated two models to have the best fit for an assessment project on construction PBFs: the OPM3 from the PMI and the MMGP-Prado. Based on those findings, the latter has the best fit for an assessment project on construction PBF. However, the model needs adjustments to fit the Portuguese context of renovation and remodelling organisations. This article presents a new PMMM for Portuguese renovation and remodelling construction firms based on obtained results. Furthermore, regarding construction PM, this article is among the few that studied PMMM on renovation and remodelling construction companies. Unlike large construction companies, these are small organisations that academics do not target for research. Full article

The challenges of adopting and implementing lean construction (LC) have led to substantial but isolated research studies concerning the relevant barriers, enablers, and implications, which lack a comprehensive approach and analytical as well as conceptual perspectives. Hence, this study aims to fill the mentioned knowledge gap by identifying the barriers, enablers, and implications of implementing lean construction and exploring their relatedness. A systematic literature review was carried out through which 230 located studies were analyzed using thematic and content analysis methods to realize the objectives of this study. The findings suggest that the lack of awareness and understanding of LC, resistance to change, and a lack of support and commitment from top management are the top three barriers toward LC adoption and implementation, which can be overcome using the identified enablers, among which the top three ones were developing lean culture, application of lean principles tools and techniques, and top management support and commitment. Moreover, the results present a model which portrays the relatedness between the discovered barriers, enablers, and implications of applying lean construction. The findings can be insightful for the research community and project practitioners in their efforts for facilitating the adoption and implementation of lean construction. Full article

There are many options and factors in the production phase of housing. In the marketing phase, houses are presented to the customer’s taste. Therefore, it is clear that a customer-oriented approach is necessary to establish a supply–demand balance in housing production on the basis of quality. This study aimed to determine customers’ housing demands in the construction sector. Within the scope of the study, 303 surveys were conducted in 30 different provinces of Turkey. The data obtained were analyzed by WEKA software with association rule extraction as the data mining method. The distribution of other attributes was determined according to two different class labels, namely the ownership status of the houses (tenant or homeowner) and customers’ expectations of the houses. As a result of the study, it is clear that people living in Turkey prefer a south-facing facade when purchasing a house. In addition, it is seen that the property owners demand 4 + 1 independent units. It is remarkable that individuals who are tenants want the living room to be spacious. The results of the study also revealed that female individuals have higher expectations of housing than male individuals. At the same time, it is understood that people’s expectations of housing differ according to the variables of age, education level, and the number of family members. The majority of the results in this study had a confidence value of 90% and above. This study was intended to serve as a guide for housing developers in Turkey to better understand and meet the demands of buildings’ residents. Full article

Concentrically braced frame (CBF) systems are susceptible to buckling (which causes a decrease in energy absorption), although this system has considerable lateral stiffness and strength. To over this shortcoming, researchers have suggested the use of I-shaped steel dampers as a practical idea that prevents buckling and increases the energy absorption but reduces the stiffness of the system. To increase the stiffness of the damper, the thickness of the web or the thickness of the flange can be increased, but by increasing their thickness the shear capacity of the damper also increases. Nevertheless, with the increase in the capacity of the damper, the forces created in the elements outside the damper will also increase, which is usually not a suitable solution. Therefore, in this paper, the use of the low yield point for the web plate of an I-shaped damper is proposed to compensate for it. Accordingly, its behavior is investigated parametrically and numerically and also requires equations to design the system proposed. Results indicated that utilizing an LYP damper improves the behavior of the system in the case of energy absorption, stiffness, and strength. Comparing the LYP damper and the conventional I-shaped damper (made of A36 steel) reveals that both dampers pertain to stable hysteresis loops without any degradation, which confirms the capability of the I-shaped damper to dissipate seismic energy. Although the flange plate properties contribute to the load-bearing of the damper, the A36 damper is more affected by the flange plate than the LYP damper that is concluded for LYP dampers the flange plate contribution in the shear strength of the damper is ignorable at the beginning of imposed loading. Full article

Spherical reticulated shell structure is an important structural form of large-span space buildings. It is of great significance to monitor three-dimensional (3D) dynamic responses of spherical reticulated shell structure to better understand its seismic performances, which will be helpful in the future to ensure the healthy condition of large-span space buildings during their lifespan. In this study, with the advantages of non-contact and high accuracy, a high-speed videogrammetric measurement method is proposed for monitoring the 3D dynamic responses of the seismically isolated, spherical, reticulated shell structural model. Two issues—the high-speed videogrammetric acquisition system and network configuration, as well as image sequence target tracking and positioning—are emphasized to achieve a cache of high-speed images and to improve the accuracy of tracking and positioning target points. The experimental results on the shaking table from the proposed method have been compared with those from traditional Optotrak Certus and accelerometers. The results prove that the proposed method is capable and useful for analyzing the seismic performance of spherical reticulated shell structures, as the dynamic responses monitoring accuracy of the method can reach the submillimeter level, with root mean square error values of 0.32 mm, 0.7 mm and 0.06 mm in the X, Y and Z directions, respectively. Full article

Building Information Modeling (BIM) has gained a lot of traction in Nepal lately due to many AEC firms’ desire to improve their productivity. This research explores the current state and potential of Building Information Modeling in the Nepalese context. The main objective of this research was to gain a holistic view of the digital design and construction approach in the AEC sectors and identify the current state of practice, future trends and opportunities, and challenges for the wider adoption of BIM in the AEC sector. A systematic survey was conducted among various AEC stakeholders; based on their responses, the status of BIM maturity is presented in this paper. We found that the lack of standards and guidelines slows stakeholders’ efforts to unify BIM implementation in projects. However, the survey results show that AEC stakeholders are eager to learn, explore, and implement BIM in their workflows of design and construction practices. The wider implementation of BIM can improve the productivity of design and construction in developing countries such as Nepal. The contributions of this research are methodological and practical. It is demonstrated in this study that qualitative and quantitative data can be integrated in different ways to allow for different avenues of analysis. The logistic regression model deployed in this study identifies the determinants of BIM use and the intensity of their effects on the future use of BIM in the Nepalese AEC industry. The findings of this study can help to formulate BIM standards and training materials that are specific to the Nepalese AEC industry. Full article

Insulating glass unit (IGU) degradation has been studied extensively. However, there is limited understanding of how present durability evaluation standards relate to product lifetime. Furthermore, there is debate on how to quantify performance of installed windows over time to better understand degradation processes. More knowledge on these topics is required to link durability evaluation to product lifetime projections based on energy performance. Energy models provide helpful estimations of total annual building energy consumption. However, most models are based on “as installed” performance of envelope components and fail to account for performance degradation. This can lead to an underestimation of building lifetime energy consumption. A better understanding of the relationship between durability and energy performance can inform integration of degradation dynamics into energy modeling software. This will improve lifetime building energy consumption estimations as well as inform appropriate retrofit strategies and timing. This paper reviews current durability literature, various standards for window performance ratings and weathering methods, existing in situ IGU energy performance measurement techniques, and whole-building energy effects. The challenges and disparities among various studies are analyzed and discussed. The authors hope that further work in this area will lead to the development of improved in situ test methods to assess IGU degradation in the field and link this knowledge to improved energy performance modeling approaches. Full article

The paper describes a method of structural repair to damaged elements of protected timber houses. Emphasis is laid on minimum intervention in the valuable material that needs to be preserved to the maximum possible extent, especially without larger interventions in the visible parts. The designs will find application in situations where it is not possible or appropriate to use common building methods, and it is necessary to carefully fill out or substitute bio-damaged parts of structural elements. The material for the production of fillings of structural elements corresponds to the originally used wood species; in the case of contact with the ground, oak is the choice due to its durability. Small caverns are filled with earth-based mortar with lime, casein, and chopped wheat straw. Such mortar mixtures were subjected to laboratory tests, which have shown that earth-based mortar (E) and earth mortar with lime putty modification (EL) have very similar physical, mechanical, and hygric properties. The properties significantly changed when curd cheese/casein was added to fresh mortar (ELC): the mechanical strength of hardened mortar increased substantially, and the diffusion of water vapours dropped, which is very beneficial for careful repairs of timber elements. The combination of timber and mortar filling provides a suitable means of repairing locally decayed timber members. Full article

Due to the rapid renovations of historical districts in the context of consumer society, contributing to the loss of city culture and identity, this paper describes the methodological study of the local schema concept on the renovations of architectural design, utilizing speculative design as opposed to inertial design. This case analysis focuses on Huaxing Street in Chengdu, China. By performing field surveys, photographing structures, and sending questionnaires to local inhabitants, an evaluation of Huaxing Street’s current status and obstacles is conducted. The conclusion of the study summarizes the audience’s satisfaction with the usage status of different renovated structures. On the basis of the idea of local schema, a spatial translation approach for architectural prototypes is given. This research explores the design methods of historical architecture in the area, history, and memory in an effort to provide guidelines for the renovation of structures in comparable historical districts. To accomplish this, prototypes for architectural installations are selected, design elements are divided, and a three-dimensional model is utilized to form a schematic replication of the building. Full article

In the case of old existing structures where the cultural value is very high, structural health analyses and investigations would be better performed without damages or service interruptions. Thus, modal analysis aimed at identifying eigenfrequencies and eigenmodes represents a very effective strategy to identify structural characteristics. In this paper, an innovative strategy to identify structural parameters exploiting the modal information obtained from operational modal analysis is proposed. The importance of the structural modeling in the problem formulation is highlighted. In the case of a simply supported beam, it was possible to assess the beam steel elastic modulus, while in the case of a cantilever beam, some constraint characteristics have been evaluated as well. In the steel frame case, the focus was on the constraint conditions of the structure determining the flexural stiffness of the springs representing the column base constraints. The method performances are promising for applications in larger structures such as bridges and buildings. Full article

This study proposes a stress analysis method of reinforced concrete (RC) box girder based on damage to reveal the dynamic mechanical response and damage mechanisms of a bridge under moving vehicle load. The effect of different vehicle mass, speed, concrete strength, and longitudinal reinforcement ratio on the stress of a single box girder is investigated using solid finite element vehicle–bridge interaction dynamic elastic–plastic analysis (a total of 13 kinds of loading schemes) that is based on the Newmark algorithms of a numerical analysis model of a five-axle vehicle and road roughness. The results reveal that the damage status of the RC box girder strongly depends on the vehicle mass and speed. The damage region of the box girder gradually increases, and changes from flexural damage to flexural-shear damage, which fails rapidly as the vehicle mass increases from 10 t to 60 t. With an increase in vehicle speed, the maximum vertical vibration displacement and the maximum longitudinal stress of the steel bar increase nonlinearly and the damage of the box girder first increases and then decreases. The most severe damage occurs at the vehicle speed of 25 m/s for all vehicle masses. As a result, limiting speed below 25 m/s under the vehicle mass (10 t to 60 t) and increasing concrete strength and reinforcement ratio in a certain range could reduce the damage status of a bridge effectively. Full article

Despite the wealth of cultural heritage objects in Indonesia, some of which are considered UNESCO World Heritage sites, more documentation still needs to be done. One of the reasons behind this problem is that the documentation of complex cultural heritage objects is more complicated than most modern objects, which are often more simplistic. This preliminary study aimed to document vernacular heritage buildings in 3D to be used as a conservation and building management tool. The built digital model can then be used as a building assessment tool. The data acquisition method used in this study was a combination of photogrammetry and laser scanner technology. The building model was stored as BIM (IFC model) and then georeferenced before being converted to IndoorGML. The building elements’ information contained in the building model was retrieved as input to analyze the building. This research included analyses for building assessment, natural room temperature, natural lighting, and indoor space and relation. All results from the analysis were used as input to calculate the reliability value of the building using the AHP method. The case study for the heritage building was the house of Prince Arya Denda at Kasepuhan Palace, Cirebon, Indonesia. Full article

The group studs arrangement is applied to prefabricated composite beams to significantly improve construction speed. However, contact vibration exists in the unconstrained interface area of the high-speed railway composite beam during the operation period, which degrades the connecting performance of the composite beam and adversely affects the overall structure. In this study, finite element simulations of the vibration of concrete slabs and steel beams in the unconstrained interface area were carried out to obtain finite element models with damage. The effects of vibration damage on the degradation of the studs were investigated by push-out and pull-out tests using finite element simulation of the local specimen model. The macroscopic ontological models of the undamaged and previously damaged group studs were obtained. Compared with the specimen without damage, the ultimate bearing capacity of the pushed-out specimen with damage decreased by 24.8%; the ultimate slip decreased by 15%; and the stiffness decreased by 12.8%. The behavior of the pulled-out specimen with damage was almost the same as that of the specimen without damage. On this basis, a finite element model of the train–track–composite beam coupling system was established. The influence of the degradation of the connection on the coupling system with 300 km/h, 330 km/h, and 360 km/h train speeds was analyzed under the conditions of single-train driving and a two-train rendezvous. In the case of single-train travel, compared with the undamaged composite beam, the mid-span vertical displacements of the composite beams with damage increased by 13%, 8.38%, and 6.2% for train speeds of 360 km/h, 330 km/h, and 300 km/h, respectively; the transverse displacements increased by 24.2%, 15%, and 9.2%, respectively. In the case of a two-train rendezvous, the mid-span vertical displacements increased by 8.8%, 13.7%, and 12.8%, respectively; the transverse displacements increased by 26.4%, 53%, and 24.8%, respectively. Full article

In order to study the bearing safety and influencing factors of the support structures of hydraulic tunnels in cold regions under the action of low-temperature frost heave, a mechanical model of the support structure and surrounding rock was established. Taking a hydraulic tunnel of a hydropower station in Xinjiang as the research object, a combination of field measurement and a numerical simulation method was adopted to study the bearing safety of the support structure during a period of freezing weather. Based on this model, the effects of different thermal expansion coefficients, temperature differences, and surrounding rock porosity on the bearing safety of the support structure in the low-temperature region were studied. From the calculation results, it was concluded that the simulation results of the numerical model established by using the mechanical model in this paper were in good agreement with the actual measurement results of the project. The circumferential freezing and compressive stresses at the arch waist of the supporting structure of the project were the largest, and significant plastic strain was generated near the arch waist. The displacement at the arch of the supporting structure was the largest, while the weak points were at the arch waist and arch top of the supporting structure. The coefficient of thermal expansion, greater temperature difference, and increased porosity of the surrounding rock all led to an increase in the rock freezing and swelling force to varying degrees, thus reducing the load-bearing safety of the supporting structure. The research results could provide a theoretical basis and a reliable mechanical and numerical simulation model for establishing the bearing safety of tunnels in the cold region. Full article

Promoting carbon reduction in the construction sector is crucial to achieving China’s ‘double carbon’ target. However, due to the interaction of multiple factors, the carbon emission efficiency of Chinese construction industry (CEECI) varies from province to province, and the path to efficient CEECI is not uniform. This study aims to analyze the combined effects of multiple factors on CEECI and to explore the underlying logic behind the formation of efficient CEECI in the province, which measures the CEECI for 2018 and 2019 for 30 provinces, autonomous regions, and municipalities directly under the Central Government of China using the super-slack-based measure (Super-SBM), which includes non-desired outputs. From a group perspective, the qualitative comparative analysis method is applied to analyze the common mechanism of the regional economic development level, energy consumption structure, business management level, market openness, science, and technology innovation level on CEECI. The results show that the regional construction industry has three equivalent low-carbon development paths: “low energy management”, “scale management”, and “scale market opening”. Finally, according to the differences in regional resource endowments, differentiated paths suitable for the low-carbon development of the construction industry in different regions are proposed. Full article