Buildings, Volume 13, Issue 9 (September 2023) – 279 articles

In order to improve the seismic and energy dissipation capacity of the whole structure, a friction-oval section mild steel rod composite damper (FOSRCD) was proposed, and its working principle was clarified. The finite element analysis of FOSRCD was carried out, and the effects of friction, frequency and displacement on the damper performance were studied. Considering the structural characteristics of FOSRCD and the mechanical models of friction dampers and mild steel rod dampers, the restoring force model of the composite dampers was proposed and compared with the numerical simulation results. The results showed that the FOSRCDs had good performance and could provide stable energy dissipation capacities in both directions, with the energy dissipation coefficient exceeding 2.3 and the equivalent damping ratio exceeding 0.37. The theoretical analysis results were in good agreement with the numerical simulation results, which verified the theoretical restoring force model; the FOSRCDs make full use of the friction energy dissipation and the shear and bending energy dissipations of the mild steel rod. It enables the two dampers to work together to achieve the purpose of multi-stage energy dissipation. FOSRCD’s structure allows it to dissipate energy in both the X- and Y-directions. The composite dampers have a variety of restoring force models and can be utilized in a wide range of practical applications. Full article

The dynamic characteristics of a multi-span double-curved brick arch thin-shell factory of Changleyuan in Baoji City and the dynamic response to train vibration load were studied using field dynamic tests and finite-element numerical simulations, and a vibration evaluation of the thin-shell factory was carried out. The results showed that the first-order frequency of the thin-shell factory was 6.24 Hz in the horizontal direction (east–west) and 9.31 Hz in the vertical direction. Moreover, it was established that the horizontal vibration is the overall vibration of the factory, while the vertical vibration is the individual vibration of the double-curved brick arch. In addition, the self-oscillation frequency obtained from the numerical simulation results was greater compared with the field measurements, with a maximum error rate of 7.14%. Both in acceleration and velocity, the vertical vibration for each measurement point was larger than the horizontal vibration, and the farther away from the railroad, the smaller the vibration. The vibration of the velocity at the bottom of the arch was almost the same as that at the top of the arch, while the acceleration vibration at the bottom of the arch was significantly larger than that at the top of the arch, with an average amplitude of 40.64%. For every 20 km/h increase in train running speed, the average increase in vertical acceleration amplitude, vertical velocity amplitude, horizontal acceleration amplitude, and horizontal velocity amplitude for each measurement point of the thin-shell factory was 35.4%, 29.8%, 23.7%, and 12.5%, respectively. When v = 150 km/h, the maximum velocity amplitude for each measurement point of the thin-shell factory was 1.163 mm/s, which is less than the security specification limit of 2.5 mm/s, such that the security of the thin-shell factory meets the requirement, and the maximum horizontal velocity amplitude was 0.272 mm/s, which is close to the integrity specification limit of 0.27 mm/s, such that the integrity of the thin-shell factory just exceeds the requirement; so it is suggested that train running speeds should not exceed 150 km/h and that the thin-shell factory needs to strengthen the monitoring and protection of its integrity. Full article

This study focuses on the development of novel evaluation methods for the analysis of thin carbon reinforced concrete (CRC) structures. CRC allows for the exploration of slender components and innovative construction techniques due to its high tensile strength. In this contribution, the authors have extended the analysis of CRC shells from existing research. The internal structure of CRC specimens was explored using microtomography. The rovings within the samples were segmented from the three-dimensional tomographic reconstructions using a 3D convolutional neural network with enhanced 3D data augmentation strategies and further analyzed using image-based techniques. The main contribution is the evaluation of the manufacturing precision and the simulation of the structural behavior by measuring the carbon grid positions inside the concrete. From the segmentations, surface point clouds were generated and then integrated into a multiscale framework using a parameterized representative volume element that captures the characteristic properties of the textile reinforcement. The procedure is presented using an example covering all necessary design steps from computed tomography to multiscale analysis. The framework is able to effectively evaluate novel construction methods and analyze the linear-elastic behavior of CRC shells. Full article

In contrast to the marine environment, coastal regions encompass substantial saline soils characterized by complex corrosive chemical compositions. This poses notable challenges to the durability of concrete structures erected in coastal dredger fill silty soil environments. This research undertook concrete chloride corrosion assessments in both a dredger fill silty soil environment and a simulated solution environment. The findings demonstrated a progressive escalation in the free chloride concentration within concrete specimens, as the exposure duration was extended from 60 to 120 d, and discernible convection zones were observed with depths ranging from 6 to 8 mm. The investigation revealed a diminishing trend in the apparent chloride diffusion coefficient, corresponding to the elongation of exposure time and the augmentation of burial depth. Paradoxically, the burial depth and exposure duration exhibited converse effects on the apparent surface chloride concentration. Empirical formulations were derived to express the apparent surface chloride concentrations and apparent chloride diffusion coefficients as dependent on the exposure time and burial depth variables. These models exhibited an excellent goodness of fit, reaching up to 0.96. Notably, concrete specimens interred at a depth of 0.0 m displayed a favorable likeness to the simulated solution environment throughout the 60 d exposure period. Full article

This study aims to enable cost-effective Internet of Things (IoT) system design by removing redundant IoT sensors through the correlation analysis of sensing data collected in a smart home environment. This study also presents a data analysis and prediction technology that enables meaningful inference through correlation analysis of data from different heterogeneous IoT sensors installed inside a smart home for energy efficiency. An intelligent service model that can be implemented based on a machine learning algorithm in a smart home environment is proposed. Herein, seven types of sensor data are collected and classified into sets of input data (six environmental data) and target data (power data of HVAC). By using the six new input data, the power data can be predicted by the artificial intelligence model. The model performance was measured using RMSE, and the gradient-boosting regressor (gb) model performed the best, with an RMSE of 22.29. Also, the importance of sensor data is extracted through correlation analysis, and sensors with low importance are removed according to the importance of sensor values. This process can reduce costs by 13%, thereby providing a design guide for a cost-effective IoT system. Full article

A reasonable material hysteretic constitutive model has a significant influence on the seismic simulation results of structures. To better describe the hysteresis seismic performance of fiber-reinforced polymer (FRP)-constrained concrete, a new modified hysteresis constitutive model is proposed based on the existing model and with sufficient consideration of the drop section of the skeleton curve. The validity of the proposed model is verified by comparing with quasi-static experimental data of FRP-confined reinforced concrete (FRP-C RC) columns in the literature. Subsequently, the compressive strength of concrete is selected as a major variable, and a quasi-Monte Carlo method is utilized to generate random samples, which are substituted into the proposed modified model and some comparison models. Finally, the hysteretic behavior of FRP-C RC columns is analyzed from the perspective of the material strength variability. The results demonstrate that (1) The proposed hysteretic constitutive model is able to provide rational predictions of the hysteretic behavior of FRP-C RC columns, and the mean relative error of each specimen is less than 6%. It can be applied to carbon FRPs (CFRPs) and glass FRPs (GFRPs), as well as different cross-sectional forms such as cylindrical and square columns. (2) A large number of hysteretic behavior cases of FRP-C RC columns can be successfully analyzed from the perspective of concrete material variability combined with finite element software. The average and variation coefficient of the maximum horizontal force of FRP-C reinforced C30 concrete columns are 76.77 kN and 0.0488, respectively, while the average and variation coefficient of the maximum horizontal force of FRP-C reinforced C50 concrete columns are 91.14 kN and 0.0454, respectively. (3) The average value and variation coefficient of the maximum horizontal force and equivalent damping ratio of FRP-C RC columns are affected by the compressive strength, axial compression ratio and reinforcement ratio, which show a certain regularity. Full article

Strain measurements have a significant role in evaluating the condition of various structural types and have become an essential component in the area of structural health monitoring. However, there are some limitations in the current means of strain measurement, and this study aims to improve these methods. We have designed a novel strain measurement method based on template matching algorithms and microscopic vision techniques, developed a new sliding strain sensor, and paired it with a new microscope to realize strain measurement. The method has the function of remote wireless acquisition with a cell phone, which is more widely applicable. In the laboratory performance testing, the zero drift of the sensor is mainly concentrated in the fluctuation range of ±2 με, and the effective range reaches nearly 40,000 με. In the comparison experiments with the linear variable differential transformer, the maximum error of the static loading is only 5 με, and the maximum error rate of the dynamic loading is less than 1%, which proves that it has a relatively high accuracy. Finally, the short-term real-time monitoring of the local structure of the footbridge was accomplished, and the strain changes on the surface of the structure were captured instantly, stably, and efficiently in the actual measurements. The proposed strain measurement system has the advantages of high accuracy, a low cost, convenient measurement, and wide applicability, and it provides a novel alternative means for strain measurement in the field of structural health monitoring. Full article

Each year, billions of tons of agricultural waste are generated globally. Egypt, being an agriculturally centered nation, faces significant challenges in disposing of this waste and coping with self-germinating plants that negatively impact agriculture. The common practice among farmers is to burn the waste, which exacerbates environmental concerns. With the global shift towards eco-friendly concrete, this study explores the utilization of agricultural waste ashes, particularly those abundant in Egypt and numerous other countries worldwide. Among the researched waste ashes are Phragmites ash (PGA), sugarcane bagasse ash (SBA), rice husk ash (RHA), and rice straw ash (RSA). This investigation examines the impact of partially substituting cement with varying ash percentages from these wastes on the characteristics and properties of fresh and hardened high-strength self-compacting self-curing concrete (HSSCSCC). The findings indicate the potential applicability of these ashes in producing HSSCSCC, specifically highlighting the promising outcome of PG ash, which exhibited favorable results as a new type of natural ash suitable for the concrete industry. Full article

Urban living space (ULS) is known to be a significant contributor to carbon emissions. However, there is a lack of studies that have considered the impact of spatial organization indexes (SOIs) of various scales on urban living space carbon emissions (ULSCE), and so far, no definitive conclusions have been reached. To address this gap, taking Tianjin as an example, the measurement methods of ULSCE and SOI at different scales were proposed, and a random forest model was constructed to explore the effects of SOI on ULSCE. The results indicated that on the district scale, Beichen had the highest carbon emissions and absorption in 2021, with carbon emissions reaching 1.43 × 10⁸ t and carbon absorption at 7.29 × 10⁵ kg. In terms of area scale, the comprehensive service area had the highest carbon emissions at 3.57 × 10⁸ t, accounting for 47.70%, while the green leisure area had the highest carbon absorption at 5.76 × 10⁵ kg, accounting for 32.33%. At the block scale, the industrial block had the highest carbon emissions at 1.82 × 10⁸ t, accounting for 54.02%, while the forest block had the highest carbon absorption at 1.25 × 10⁶ kg, accounting for 91.33%. Each SOI had varying impacts, with the industrial land ratio (ILR) having the highest order of importance at the area scale, followed by road network density (RND), residential land ratio (RLR), bus station density (BSD), public service facilities land ratio (PLR), land mixing degree (LMD), open space ratio (OSR), and commercial land ratio (CLR). ILR, RND, and RLR were particularly important, each exceeding 10%, with importance values of 50.66%, 17.79%, and 13.17%, respectively. At the block scale, building area (BA) had the highest importance, followed by building density (BD), building height (BH), land area (LA), and floor area ratio (FAR). BA and BD were particularly important, with values of 27.31% and 21.73%, respectively. This study could serve as both theoretical and practical guidance for urban planning to aid the government in developing differentiated carbon emissions reduction strategies that can mitigate the heat island effect and promote low-carbon healthy urban planning. Full article

Bacterial concrete is a possible approach toward sustainability in concrete construction through crack-healing. Including a bacterial culture as an admixture in concrete can enhance the service life of a structure through the self-healing of cracks. Incorporating bacterial cells as an admixture in concrete is a major challenge as bacteria are living organisms with a limited shelf-life. It is essential to evaluate the shelf-life of bacterial cultures to encourage the inclusion of bacteria in concrete applications. Hence, the main focus of this study was to record the cell viability of these microorganisms before addition to cementitious systems. In the first stage, three different bacterial cultures of Bacillus subtilis, Bacillus cereus, and Bacillus licheniformis were stored in Luria Bertani broth under two different conditions of room temperature and refrigeration. These stored bacterial solutions were checked for viability based on cell count after 1 day, 3 days, 7 days, 15 days, and 20 days of storage. In the second stage, the fresh bacterial cultures and the 15-day stock were added to prepare bacterial concrete and cement paste samples to assess their compressive strengths and microstructural changes, respectively. It was observed that the cell viability in terms of cell count of the selected bacterial strains attained up to 15 days when stored at room temperature. It was also observed that the compressive strength of the bacterial concrete prepared with stored bacterial cultures increased by 6% and 11% at 7 and 28 days compared with the control Portland cement concrete mix, respectively. However, the compressive strength decreased by 6% to 12% compared with the bacterial concrete prepared with fresh cultures at the same ages. Additionally, the compressive strength results were validated using microstructural analyses. Full article

The atrium space represents one of the most energy-intensive areas within buildings. This is especially evident in college teaching buildings, where the inclusion of atriums often leads to increased energy consumption, primarily due to enhancements in lighting and thermal comfort. To address this issue, this study investigates atriums in cold regions within college teaching buildings and establishes four distinct atrium models for such buildings through typological abstraction and evolution. This study utilizes the Grasshopper (Ladybug Tools; developed by Robert McNeel & Assoc, Inc. in the United States.) parametric performance simulation platform to simulate daylight comfort and energy consumption within the atriums. Range analysis is subsequently applied to assess the impact of variables on energy consumption, and variables with the least influence are eliminated. Subsequently, the Octopus plug-in is employed to conduct multi-objective optimization for the four atrium types, resulting in the attainment of a Pareto-optimized solution set. Following optimization, the energy efficiency rates for the four atrium types are determined as 10.3%, 17.6%, 37.2%, and 30.5%, respectively, while the daylight comfort rates experience enhancements of 4.4%, 10.4%, 44.7%, and 34%, respectively. This study provides designers with a reference for optimizing design parameters during the early stages. Full article

BIM has become an intrinsic tool in managing building projects due to its ability to comprehensively represent information in digital form. However, using BIM as an information exchange tool is still in its infancy, particularly with regard to construction progress monitoring beyond time schedule information. The current study focuses on the development of an automated progress monitoring framework based on an IFC-based BIM and provides an extensive methodology based on a structured task-based approach in accordance with the latest IFC4.x schema in four stages. The first stage creates the appropriate IFC entities, which are then enriched with their values in the second stage. The third stage integrates the actual progress information, which requires regular updating from the construction site. Finally, the fourth stage enables the retrieval of progress information, which is then reported in a user-friendly format along with the estimation of additional progress indicators. The proposed method successfully integrated the progress information into their IFC-based BIM models, demonstrating its practical use for monitoring construction progress. In the end, a web-based application was also developed that made use of progress information stored within the standardized hierarchy of the updated IFC-based BIM to facilitate efficient reporting. Full article

To overcome the limitations of using time interval division to calculate the bridge impact coefficient (IM), a sieving method has been proposed. This method employs multiple sieves on bridge time–history curve samples to ultimately obtain the bridge impact coefficients. Firstly, CA cellular automata are used to establish different levels of traffic flow fleet models. The random traffic flow–bridge coupling dynamic model is established through wheel–bridge displacement coordination and mechanical coupling relationships based on the theory of modal synthesis. Then, the variation of bridge dynamic time–history curves for different classes of random traffic flow, speed and pavement unevenness parameters are analyzed. The sieving method is applied to screen the extreme points of the dynamic time–history curve of the bridge, enabling the distribution law of the bridge IM to be obtained using the Kolmogorov–Smirnov test (K–S test) and statistical analysis. Finally, the calculated value is then compared with the IM specifications of multiple countries. The results show that the proposed method has high identification accuracy and produces a good inspection effect. The value obtained using the sieving method is slightly larger than the value specified in the US code, 0.33, which is considerably larger than the values specified in other national codes. As pavement conditions deteriorate, the IM of the bridge increases rapidly, especially under Class C and Class D pavement unevenness, which exceed the values specified in various national bridge specifications. Full article

Cold-formed steel (CFS) structures are widely used in construction and infrastructure due to their lightweight and high-strength properties. However, their thin-walled nature makes them geometrically sensitive to compressive loading. The Digital Twin (DT)-based numerical simulation method is developed using the actual geometries of CFS shapes, which are acquired by a 3D laser scanner. The DT-based numerical simulation incorporates the reconstructed measurement point clouds into the finite element modeling, ensuring that actual geometric features are retained. A series of tests, including material and axial compression testing, are conducted to validate the modeling parameters, such as mesh sizes and boundary conditions. The advantages of the DT-based numerical simulation method are highlighted compared to the traditional CFS member numerical simulation, which incorporates only the first mode of geometric imperfection. Additionally, DT-based numerical simulations offer more accurate load capacities and deformation predictions. Moreover, the automated and validated DT-based numerical simulation demonstrates prevalence in modeling efficiency and computation effectiveness. The DT-based numerical simulation method holds potential for application in smart structural analysis, where accurate geometries derived from extensive measurement point clouds are integrated into numerical modeling. Full article

The aim of this research is to assess sustainable green building awareness in Kano State, in a case study of the Gwale local government area. This research makes use of both primary and secondary data to address these offered solutions. Descriptive and quantitative analysis using the BREAM and LEAD evaluation standards was used to analyze the case study and 251 questionnaires were distributed. To ensure a fair trial of each of the 251 building samples, they were chosen at random from various parts of the Gwale Yan-Alawa ward. A case study of a selected green building was chosen and analyzed. The logical comparison with Saudi Arabia was made. It is concluded that the Nigerian government at the national level should put more effort into encouraging green building construction through public awareness programs and incentives and subsidizing the green system. Full article

In order to reach a Zero-Energy-consuming building stock, it is necessary to insulate and add renewable energy sources on top of existing building envelopes. Off-site prefabricated modules have been used for covering building facades, but manual on-site installation procedures are still more competitive than prefabricated ones. Renovation with prefabricated modules requires high precision in order to obtain airtight and waterproof conditions. For that, an accurate installation of the anchors on top of the facade is crucial. With current techniques, this is a time-consuming operation. One of the attempts to solve the above-mentioned issue was to place the part of the anchor on top of a building facade with high tolerances and to use an interface to correct the deviations. In previous research, this concept, named Matching Kit, was validated, but improvements needed to be made to make it more competitive. In this paper, thanks to novel algorithms and the use of Point Clouds, an improved version is presented. The results show a reduction in working time and an increase in precision. With this research, the interface is closer to being used in the construction industry. Full article

Climate change will have a great impact on the hottest climates of southern Europe and the existing residential stock will be extremely vulnerable to these future climatic conditions. Therefore, there is an urgent need to update this building stock considering imminent global warming by applying climatic files that predict future conditions in building performance simulations. This research makes use of the two most applied tools (Meteonorm and CCWorldWeatherGen) for generating future climate hourly datasets for 2050 and 2080 in southern Spain. The results predicted for outdoor and indoor thermal conditions and cooling and heating demands are evaluated for two different scale simulation models: a test cell and a multi-family building located in southern Spain. The main aim of this work is the development of a comparative analysis of the results to highlight their potential differences and raise awareness of the influence of the climate data projection method on the simulation outcome. The results show that the projection method selected for producing future climatic files has relevant effects on the analysis of thermal comfort and energy demand, but it is considerably reduced when an annual evaluation is developed. Full article

This study investigated the effects of mixture proportions and vibration levels on the physical properties, durability and performance of concrete used in Korean pavements. The strength and durability characteristics varied depending on the mixture proportions and level of vibration, and samples with fly ash (i.e., F-CON) did not meet the strength and durability criteria when low levels of vibration were applied. Therefore, intermediate or higher levels of vibration should be applied to satisfy strength and durability criteria. Meanwhile, there was little difference in the performance tests (i.e., skid resistance, surface abrasion, and IRI) of concrete pavements depending on the mixture proportions and vibration levels. However, the sample with an intermediate level of vibration had a relatively higher performance than the other samples. Full article

This paper addresses the current imbalance in construction social procurement research toward Western countries with neo-liberal models of public governance. It does this by exploring the potential value of construction social procurement in the Chinese centralized unitary state and socialist market system. Findings from a survey of one hundred and sixty-four professionals from the Chinese construction industry are reported. They highlight the institutional foundations into which social procurement could be implemented and the significant untapped social value that could be created. However, they also show that for social procurement to achieve its full potential in the Chinese construction industry, such policies need to be underpinned by meaningful industry consultation, effective education and clearly mandated targets that create a market for social value. This paper contributes to the global advancement of social procurement research in construction by providing new insights into the implementation of social procurement beyond the narrow confines of the Western political and governmental orthodoxies where such research has hitherto been focused. Full article

Modular steel buildings show high assembly degree and fast installation speed. The inter-module connection (IMC) is one of the key technologies that restrict the robustness of modular steel buildings. An innovative IMC with a cross-shaped plug-in connector is proposed, and the connection consists of end plates of columns, the cross-shaped plug-in connector, bolts, cover plates, and one-side bolts. The proposed IMC is easily constructed, and the cross-shaped plug-in connector can improve the shear resistance of the core area. The mechanical model of the proposed IMC is presented, and the panel zone volume modified factor and initial rotational stiffness modified factor are proposed for calculating the shear capacity of the panel zone and the initial rotational stiffness. Numerical simulation was conducted considering the influences of axial compression ratios, sections of beams and columns, and the thickness of the tenon plate of the connector. The bearing capacity of the proposed IMC was analyzed, and the values of the two factors mentioned above were calculated, and their regression formulas are presented. The results show that the sections of beams and columns and the axial compression ratios show great influences on the bearing capacity of the proposed IMC, while the thickness of the tenon of the cross-shaped plug-in connector shows almost no effect. In addition, the sections of beams and columns show great influences on the shear capacity of the panel zone, as well as the initial rotational stiffness of the proposed IMC, while the thickness of the tenon of the cross-shaped plug-in connector and the axial compression ratios show little effect and almost no effect, respectively. Furthermore, the bending moment limit of the beam end of the proposed IMC is suggested to be 0.6 times the resistance bending moment, and the proposed IMC is considered to be a rigid connection or inclined to a rigid connection The proposed IMC has good mechanical performance, and design recommendations are presented. Full article

Under the trend of digitization and global carbon reductions, clay construction has increasingly attracted attention due to advantages such as an excellent thermal performance, low carbon emissions, and high cost-effectiveness. In this article, an in-depth investigation is conducted into the potential, challenges, and future in the development of digital manufacturing technologies for clay architecture, especially 3D printing, robotic construction, and prefabrication systems. It is revealed through a review that digital clay construction is under rapid development and likely to provide a viable solution to achieving global carbon neutrality, which is conducive to addressing various regional issues. The key findings from this review are as follows. Firstly, as a flexible, precise, and low-carbon industrial solution, 3D printing lays a foundation for the extensive research on materials, equipment, and algorithm optimization. Secondly, the use of machine construction methods such as modern rammed earth technology and drone spraying is effective in improving efficiency and lowering costs. Lastly, the prefabricated building system shows its potential in renewing and developing the rammed earth architecture culture. These findings indicate a massive potential of digital clay construction to support sustainability efforts in the future. Full article

In order to analyze the thixotropy of mastic asphalt concrete during the mixing process, the factors affecting the thixotropy of mastic asphalt binder and asphalt mastic are studied, and the measures to shorten the mixing time of mastic asphalt mixture are given. The dynamic viscosity of mastic asphalt binder and asphalt mastic with time and shear rate is obtained via the step frequency method, and the thixotropic constitutive models of mastic asphalt binder and asphalt mastic are constructed by structural dynamics model, exponential equation, and extended exponential equation respectvely. The improved time thixotropy index is used to analyze the effects of asphalt type, asphalt–aggregate ratio, filler type, heating temperature, and shear rate, and the laws of various factors affecting the thixotropy of mastic asphalt binder and asphalt mastic are obtained. The research shows that the extended exponential model can better characterize the thixotropy of mastic asphalt binder and asphalt mastic under different shear rates. When the amount of lake asphalt or cement is increased, the viscosity of the system and the mixing time to reach a steady viscosity increases; that is, the mixing time needs to be increased. Increasing shear temperature does not change the time parameter to reach steady viscosity; that is, it cannot shorten mixing time. When the shear rate is increased, the time for the system to reach the steady viscosity will be shortened; that is, the time for mixing the mixture can be shortened. Full article

This research aims to determine the appropriate level of effort required for each step of the Observe–Plan–Do–Check–React (OPDCA) cycle to improve the workflow reliability of a construction project. Empirical data on detailed weekly meeting minutes over 18 weeks and the planned and actual starting and finish times of 475 activities were collected from a bridge construction case project. The information theory approach was utilized to measure the information gained from discussions pertaining to the OPDCA cycle during weekly planning meetings. Cooperative game theory and the Shapley notation of fairness were used to compute the contribution of each OPDCA step to workflow reliability. Results showed that “Observe”, “Plan”, “Do”, “Check”, and “reAct”, contributed 18%, 23%, 23%, 24%, and 12% to observed variations in workflow reliability measured by the percent plan complete (PPC). Also, findings revealed that synergy exists between the “Check” step and other steps in the OPDCA cycle. The methodology developed in this paper has potential implications for engineering managers. The method can be generalized to help project managers find the balance between planning and control efforts to improve workflow. It also provides proven techniques for continuous improvement during project execution to facilitate project success. Furthermore, at the organizational level, the developed method can help higher-level managers make informed investment decisions for employees’ training and development to improve performance in future projects. Full article

The beam-only connected reinforced concrete shear wall (BRW) is used as a reinforcing component to enhance the seismic performance of concrete-filled, double-skin steel tube (CFDST) frames. The effects of the BRW on seismic risks of CFDST frames are investigated. Three performance levels of limit states are defined and described according to the typical failure of test specimens and the existing definition of current guidance. A simplified numerical model is calibrated for CFDST frame-BRW structures, and test results validate it. Nonlinear dynamic analyses on a nine-story CFDST-BRW building are performed to investigate the effects of BRW on reducing the seismic risk of CFDST buildings. The results show that the BRW reduces the probability of collapse of the CFDST frame to 2.76% in 50 years, which can effectively reduce the probability of different degrees of damage in the service cycle of the structure. The results provide information for risk-informed decision-making on the design of CFDST frame-BRW structures. Full article

To study the force and deformation characteristics of a full-section immersed tube with post-pouring belt under the action of hydration reaction, the numerical model of full-section immersed tube with post-pouring belt was established by using MIDAS FEA (V2013) finite element analysis software, and the stress, cracking and deformation of the segment of the post-pouring belt were analyzed. The results show that under the action of hydration reaction, the concrete reaches the highest temperature at about 36 h, which appears at the roof of the tube gallery in the immersed tube, and the bottom steel plate expands rapidly initially, and subsequently shrinks gradually. The outer surface of the post-pouring segment concrete is stretched, and the internal region is under pressure, and as the internal temperature of the concrete cools down, the bottom plate starts to contract. The steel bar connection between the post-pouring belt and the surrounding immersed tube segment will increase the risk of cracking in the bottom plate of the full-section immersed tube. When only the steel bars in the bottom plate are connected, the maximum tensile stress of the immersed tube bottom plate will increase by 16.0% compared to the no connection case. If the steel bars of the immersed tube’s web and roof are also connected, the maximum tensile stress will increase by over 20%. By connecting the steel bars, the peripheral tube section plays a certain role in limiting the transverse deformation of the post-pouring belt and constraining the reinforcement of the bottom plate and web (and roof) can reduce the transverse deformation of the immersed tube to a great extent, reducing the proportion by over 10%. Full article

Reinforced concrete infilled frames have been studied over the years along with the infilled openings. To resist the lateral loads that are applied on the frames, stress is transferred from the reinforced concrete (RC) to infill, which leads to brittle collapse. The conventional interface medium, which was considered by researchers and recent studies, was prepared by changing the interface materials between the RC frame and infill panels to different elastic materials. This study focuses on optimizing the interface pressure using a butyl rubber tube, which reduces the stress distribution to the infill panel from the RC frame. A 50% window opening was adopted in this study, which is the optimized size from previous research. The optimization patterns followed linear and nonlinear patterns, such as the same pressures in all stories and varying pressures in all stories. The third story had a 8 PSI pattern and the other stories had a 2 PSI pattern; all stories with 8 PSI patterns achieved the least displacement when compared to other variations. A monotonic static analysis was performed for both the experimental and analytical study. The boundary conditions were pinned, and coupling interfaces were made for the master and slave surfaces. The pressure conditions were applied in various linear and nonlinear patterns to optimize the pressure. A comparative study was performed on the displacement, stiffness, and drift ratio for the critical position of the interface pressure in both the analytical and experimental studies. The difference was approximately 0.53% in the analytical study and 0.37% in the experimental work. The optimization was performed using both an experimental model and an analytical model, which had an error percentage of 0.61%. Full article

Ultra-high-performance concrete (UHPC)-filled duct connection is an innovative solution for joining assembled structures, in which the anchorage performance of the rebar and UHPC filled in bellows plays a critical role in determining the overall connection effectiveness. To establish a reliable anchorage length and a bond–slip relationship between rebar and UHPC within a bellow, a total of 16 specimens were conducted, and pullout tests were carried out. Two parameters were considered, including the diameter ratio (D/d), representing the proportion of the diameter of the bellow D to the diameter of the steel bar d, and anchorage length (L). By analyzing the failure modes, load versus deflection curves, and steel strain data, the influences of the diameter ratio and anchorage length on the anchorage performance were discussed. The test results showed that the failure mode changed from rebar pullout to rebar breakage as the anchorage length increased from 3 d to over 10 d. The reliable anchorage length of the rebar was recommended to be at least 10 d with a diameter ratio (D/d) of 2.4. Moreover, a fitting bond–slip model was proposed based on the experimental bond–slip curves between the rebar and UHPC interface within the bellows with high precision. These findings constitute a crucial basis for the comprehensive stress analysis of assembled structures connected using UHPC grouted in bellows. Full article

This study determined how replacing sodium nitrate-based antifreeze admixture (AF) with belite-calcium sulfoaluminate (belite-CSA) cement affects the early age properties of ecological concretes based on ordinary Portland cement (OPC) and ground granulated blast-furnace slag (GGBFS). Concrete specimens were cured at −15 °C and treated in various ways before testing, i.e., no treatment, stored at 20 °C for 12 and 24 h. Generally, the addition of belite-CSA cement shortened the setting time due to the rapid formation of ettringite. The incorporation of 25 wt% of antifreeze admixture (AF) to the OPC-GGBFS concrete cured at −15 °C partially inhibited ice formation and enabled the continuation of hydration processes. This trend was observed for all samples, independent of the applied AF after freezing curing. On the contrary, the addition of 20 wt% of CSA failed to inhibit the ice formation and increased the risk of frost damage for concretes despite the treatment after freezing. These concrete specimens had lower hydration, lower strength, and a more porous binder matrix. The microstructure of the binder matrix was significantly affected by the amount of CSA and extreme negative curing, followed by no notable recovery post-curing at room temperature. Therefore, pre-curing at room temperature for at least 6 h has the potential to avoid frost damage. Concrete containing 25 wt% AF combined with 12 h and 24 h of curing at 20 °C after removal from freezing and prior to testing could enhance the compressive strengths of all concretes. The renewed hydration was indicated as the main influencing factor. Full article

Information management is an important development direction in the field of tunnel engineering, and BIM technology provides an important approach for the realization of it. However, standardization is the first step of the implementation of BIM technology. Only through a set of unified BIM standards for tunnel engineering can the late platform development with information sharing and exchange be carried out normally and orderly. In view of the current lack of unified BIM technology standards and related theoretical research in the field of tunnel engineering, this paper proposes a theoretical framework for the study of a BIM technology standard in the field of tunnel engineering on the basis of the existing standardization research work and establishes a new maturity model in the field of tunnel engineering for the first time. On this basis, this paper classifies and codes the information in the field of tunnel engineering and carries out a series of preliminary studies and discussions on the standardization of BIM technology in the field of tunnel engineering, initially establishing a relatively complete system of BIM technology standards. With the Daliangshan Tunnel under construction in Sichuan Province of China as a pilot application case, the feasibility of the proposed standards is preliminarily verified. In addition, this paper puts forward the new concept of “standard degree” for the first time and tentatively discusses the relationship between the standard degree and four influencing factors, the standard unity degree, the recognition degree of project participants, the applicable degree of software and the perfection degree of platform construction, which provides a reference for subsequent related research and promotes the development of BIM technology standardization and the management process of information in the field of tunnel engineering. Full article

The acoustic environment can influence people’s perceptions and experiences and shape the soundscape. The soundscape has a unique role in shaping the cultural identity of a regional culture. Artificial sounds are an essential source of sounds in historical blocks; research has shown the influence of the ratio of perceived artificial sounds to the perceived extent of natural sounds on environmental perception in historical blocks. In order to explore this impact, this study uses the red soundscape index (RSI_n), which represents the ratio of perceived artificial sounds to natural sounds, and constructs a structural equation model to elucidate the relationship between RSI_n, soundscape perception, and sense of place. The results show that: (1) The evaluation of the sense of place is inversely related to the perception of artificial sounds and positively related to the perception of natural sounds. (2) Different artificial sounds have different effects on soundscape perception and the sense of place; the traditional culture soundscape index (TRSI_n) has a significant impact on soundscape pleasantness (β = −0.13, p < 0.001) and soundscape quality (β = −0.09, p < 0.01). (3) The human soundscape index (ARSI_n) has a significant impact on the sense of place (β = −0.14, p < 0.001). (4) The music soundscape index (MRSI_n) has a significant negative impact on soundscape quality (β = −0.13, p < 0.05) and the sense of place (β = −0.12, p < 0.05). Therefore, the different dominant artificial sound sources should be considered and emphasized when designing and optimizing the soundscape of historic districts. The results of this study can serve as design guidelines and supporting data, providing a reference for the optimization and enhancement of the soundscape of historical blocks. Full article