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A specialised emergency field hospital was constructed in record time in Wuhan, China shortly after the initial outbreak of the Covid-19 pandemic. Covering an area of 34 000 m2 and providing 1000 beds, Huoshenshan Hospital was more advanced and had more rigorous isolation systems than most current infectious-disease hospitals, but it was delivered in just 10 days. The rapid construction benefited from a unique modular design, over 4000 people who worked around the clock and a series of advanced technologies such as building information modelling, modular construction and 5G communications. The hospital played a crucial role in controlling the pandemic in China.

Owing to the rapid construction and rebuilding activities occurring in the country, huge amount of construction and demolition waste is generated. To cater the needs for disposal of this waste, recycling them for use in road construction has great potential and is important for sustainability. In order to address the same, a study has been carried out to explore the use of waste materials such as recycled concrete aggregates (RCA) in pavements. In this paper, few treatment methods of RCA such as acid treatment, thermal treatment and bituminous emulsion have been compared to adjudge the best treatment of RCA. For purpose of comparison, mixes were made using different treatment techniques with RCA. It was observed that the mixes comply with the standards specified in MoRTH, India in terms of Marshall Characteristics and moisture susceptibility. Bituminous emulsion treated RCA was found to be the most appropriate treatment method.

The rapid construction of a shaft is very important for shortening the shaft construction period and improving the mine economic benefits. In addition to the effects of hydrogeological conditions, ...

Newly laid asphalt must be adequately cool before it can be trafficked to prevent the development of costly premature damage. Selecting an appropriate traffic-opening temperature of newly laid asph...

Appropriate transfer of the shear force of a perfobond strip used as a shear connector in steel concrete hybrid structures depends on the restraining effect around the strip, and hence, the arrangement of the surrounding reinforcements is very important to improve the restraining effect. However, when the perfobond strip is arranged in narrow joint structures and when the rapid construction is also required, reinforcements are undesirable on the site. An alternate method to improve the restraining effect around the perfobond strip is to use steel fiber-reinforced mortar (SFRM). This study aims to evaluate appropriately the shear capacity of a perfobond strip with SFRM without surrounding reinforcements for narrow joint structures. Assuming these conditions, pull-out tests were conducted, and the data obtained were considered along with the results of push-out tests conducted in the previous study of the authors. Based on the results of both test series, the impacts of various factors on the shear capacity of the perfobond strip was analyzed comprehensively. The results showed that the shear capacity of a perfobond strip with SFRM increases with the perforation diameter, SFRM compressive strength, volume content of steel fibers in the mortar, and dimensions of the mortar block around the perfobond strip. Moreover, the plasticization of the perfobond steel plate and the difference in boundary conditions between the push-out and pull-out tests also affect the shear capacity of the perfobond strip. An equation was proposed for evaluating the shear capacity of the perfobond strip with SFRM without any surrounding reinforcements for narrow joint structures. The shear capacity obtained using the proposed equation has high correlation with the experimental value for both push-out and pull-out specimens.

Being cost-effective, rapid construction, high transportability, and maintainability, post-tensioned precast concrete segmental bridges (PT-PCSBs) have been one of the most preferred choices for sites that are restrictive to access. Yet, deterioration due to aging, improper maintenance, and unaccounted shrinkage of bridge decks can cause unexpected prestress loss/gain and alter the structural behaviour of PT-PCSBs, especially with unbonded external tendons. In this regard, this paper presents the development of a rigorous and detailed three-dimensional discrete finite element model (DFEM) for a PT-PCSB, of which both global load-deflection behaviour and local responses were verified against experimental results by Takebayashi et al. (1994) and Jiang et al. (2018). The verified model was then adopted to investigate the effects of prestress loss/gain on the structural responses and failure behaviour. Based on the analysis results, a 20% increase/decrease of prestressing can lead to a 10% increase/16.8% decrease of the moment resistance but a 30.2% decrease/36.6% increase of the deflection capacity. At large prestressing level, e.g. 0.874 f pu , significant crushing of concrete can occur in the bottom region of the bridge at ULS that significantly restricts the joint opening, tendon strain development, and ductility. On the contrary, at the extremely low prestressing level of 0.125 f pu , the bridge decompresses under its self-weight and is very unstable under additional load, resulting in very low ductility and moment resistance. Furthermore, for a regular prestress level of around 0.6 f pu , the stress change in tendons from the effective prestress to the stress in ULS matches the recommendations by ACI318 and AASHTO LRFD but is underestimated by EC2. Yet, the ultimate tendon stress which is less sensitive to the prestress change may be more suitable than the stress change in evaluating the ULS behaviour of PT-PCSBs with unbonded tendons.

The construction of water conservancy projects in cold regions experiences freezing-thawing cycles, which can greatly change the engineering properties of soil and have a significant impact on the construction of projects. Lianghekou Hydropower Station (LHS), is a controlling station with the largest installed capacity among the 7 middle reach projects in the Yalong River, the secondary tributary of the Yangtze River. LHS is located in a seasonally frozen soil area. Based on the measured data of air and ground temperature in winter in the dam core wall, the freezing-thawing variation of gravelly soil and contact clay during the filling process of the core wall are compared and analyzed, then the main impact factors of the freezing-thawing variation of soils are discussed. The results show that under the influence of air temperature, soil freezes unidirectionally from ground surface downward and deepens gradually, and the thawing processes are different at the aspects of thawing direction and rate. Air temperature and physical properties of soil including soil type, moisture content and dry density affect the freezing-thawing processes of soils. And the impact of engineering construction is more remarkable than natural factors. The engineering construction affects soil temperature and freezing-thawing process by controlling the initial temperature of soil, the speed and duration of the technological conversion of paving, compaction, and the length of placed duration at night. Due to the long placed duration of soil with the slow construction method, the initial temperature of soil gradually reduces, the heat transfer process inside soil is fast. Then the internal heat of soil releases, the decreasing rate of ground temperature of soil at different depths is fast and the frozen depth deepens. While due to the short placed duration of soil with the rapid construction process, the initial temperature of soil is high, high internal heat of soil is supplied every day, and the heat transfer process inside soil is slow. Then the decreasing rate of temperature of soil at different depths is slow, and the variation amplitude of frozen depth is small. This study provides useful guidance for the freezing-thawing prevention during the construction process of core wall dams located at high altitude region in winter.

The stability of the surrounding rock masses of underground powerhouses is always emphasized during the construction period. With the general trends toward large-scale, complex geological conditions and the rapid construction progress of underground powerhouses, deformation and failure issues of the surrounding rock mass can emerge, putting the safety of construction and operation in jeopardy and causing enormous economic loss. To solve these problems, an understanding of the origins and key affecting factors is required. Based on domestic large-scale underground powerhouse cases in the past two decades, key factors affecting the deformation and failure of the surrounding rock mass are summarized in this paper. Among these factors, the two most fundamental factors are the rock mass properties and in situ stress, which impart tremendous impacts on surrounding rock mass stability in a number of cases. Excavation is a prerequisite of surrounding rock mass failure and support that is classified as part of the construction process and plays a pivotal role in preventing and arresting deformation and failure. Additionally, the layout and structure of the powerhouse are consequential. The interrelation and interaction of these factors are discussed at the end of this paper. The results can hopefully advance the understanding of the deformation and failure of surrounding rock masses and provide a reference for design and construction with respect to hydroelectric underground powerhouses.

Accelerated bridge construction (ABC) has been used extensively to achieve rapid construction, to reduce traffic congestion and environmental impacts, and to ensure reliable quality control...

The compaction of over-wet fluvioglacial deposits filler is difficult due to its high moisture content. This paper presents an easy but effective improvement method to treat over-wet fluvioglacial deposits using quicklime. Firstly, several tests are conducted to figure out the properties of the over-wet fluvioglacial deposits. Then, the relationship curves between the difference of natural-optimal moisture content and compaction degree are established. Finally, field test is carried out and the compaction degree of the subgrade soil is evaluated by sand cone method. The field test in the case study shows that the moisture content difference of filler is 10.9%, and the optimal quicklime content is 6% according to the curves. Results indicate that the average compaction degree of subgrade soil is 94.90% (>93%) and the value of CBR is much higher than required 3%, which proves that the method using quicklime works well to improve over-wet fluvioglacial deposits filler for rapid construction of highway embankment. Considering the inadequacy of stiffness of quicklime-treated filler, the rapid increase of stiffness for the upper roadbed using over-wet fluvioglacial deposits filler needs further research.

In recent years, the technology and applications of visualizations on large high-resolution displays (LHDs) have received widespread attention because of its perceptual benefits and improved productivity. However, existing work on LHD visualization lacks both comprehensive guidance for design requirements and tools developed for its specific usage scenarios. In this paper, we present the scenarios, design, and implementation of DataV, a Software-as-a-Service (SaaS) visual deployment tool that enables rapid construction and cross-platform publishing of interactive visualization on LHDs. Our framework can support rich components for the high-performance rendering of multi-source heterogeneous data. DataV provides a full-fledged toolchain to help the user efficiently specify layout and interactions. We present its accessibility and impressive visual effects with examples and comparison with Tableau, Power BI, VisComposer, and iVisDesigner. We also report the performance of using DataV for 3D map rendering by comparing it with deck.gl.

In recent years, the ecological environment along highways in Tibetan Plateau has been severely affected due to the rapid construction of highways. In order to solve the problems of multiple indicators and inconsistent criteria in the ecological impact assessment of highways, and to scientifically screen assessment indicators, the paper proposes a multi-round indicator screening method, which combines literature analysis, expert rating, and statistical analysis. Based on this screening method, normalized difference vegetation index, land surface temperature, elevation, and normalized difference soil index are screened out. Combined with multiple linear regression, an ecological impact assessment model is established and applied to ecological impact assessment of Gonghe-Yushu Expressway. The results show that the expressway construction is the first driving force for the deterioration of the ecological environment along the roadside, and its interference range on the desert grassland ecosystem is greater than that on the agroforestry system. The ecological environment within 150 m on both sides of the expressway should be protected.

Yapı sektörünün sosyal ve ekonomik gelişmede önemli bir rolü olmasına rağmen çevresel etkilerin oluşumunda da belirgin düzeyde etkili olduğu bilinmektedir. Bu etkilerin azaltılması yönünde uluslararası, ulusal, bölgesel ve yerel ölçeklerde ekolojik tasarım yaklaşımlarının tartışıldığı ve çeşitli yöntemlerin oluşturulduğu bilinmektedir. Türkiye’de ise, çok sayıda ve hızlı konut üretimi yapılmasına rağmen, konut üretiminde ekolojik yöntemlerin dikkate alınmadığı gözlenmiştir. Bu tespitler doğrultusunda çalışmanın amacı oluşturulan ekolojik performans değerlendirme modeli ile seçilen mevcut konut grubunu değerlendirmek ve ekolojik performansını tespit etmektir. Çalışma kapsamında öncelikle; etkin hammadde kullanımının, etkin enerji kullanımının, etkin su kullanımının ve çevre korunumunun ekolojik tasarımdaki etkileri üzerine literatür taraması yapılarak konut grupları için ekolojik tasarım kriterleri belirlenmiştir. Bu kriterlerden oluşturulan ekolojik performans değerlendirme modeli ile Kocaeli ili Darıca ilçesinde yer alan 30 adet konut grubu incelenmiştir. Yapılan inceleme sonucunda örnek konut grupları etkin hammadde kullanımında %36, etkin enerji kullanımında %52, etkin su kullanımında %30 ve çevre korunumunda %27 performans göstermiştir.

Introduction : The article presents a study and justification of the concept for the erection of prefabricated buildings out of modules on a pre-arranged foundation with a comprehensive assessment of quality, accuracy, constructability and safety of building superstructure blocks. Purpose of the study: Development of rapid construction is driven by the need for affordable housing in Russian towns and cities, the need for the erection of buildings of various purposes within short time frames in regions with severe and extreme climate. Methods: Prefabricated construction is a promising industry, but it is required to perform studies on the selection of optimal organizational and technological solutions, aligning those with modern standards and requirements. Results: The authors consider a method of choosing a technique for the construction of pile foundations for multi-purpose prefabricated buildings with account for the analysis of existing loads and structural features. Determination of constructability criteria makes it possible to assess the comparative efficiency of the prefabricated-construction techniques with account for data of geotechnical surveys, conditions of a construction site, etc.

With the rapid construction and deployment of LTE, the multi-standard, multi-element and multi-level network topology framework of mobile wireless network has been formed, and the fine configuratio...

The discordance between the operation of rail transit and surrounding land use is highlighted with the rapid construction of rail transit in China. The related research on coupling relationship is well needed. Taking 13 typical commercial service rail transit stations in Xi'an as the example, this article established the evaluation indicator of coordinated relationship between rail transit station operating efficiency and land use, and a data envelopment analysis (DEA)model was used to evaluate the coupling degree between them. According to the research results, the coupling development between operating efficiency and land use in Xi'an commercial service rail transit station is at a low level and there exists a huge difference between the two. Moreover, this research identified the key indexes that influence the coupling development of the two, namely Class-A, Class-B, and Class-R land use proportion, plot ratio, land use mixture and parking facility control, and determined the reasonable control range of these four indices. The research promotes the intensive use of land around Xi'an rail transit station and better supports the sustainable operation of rail transit.

Iodocyclization of ethoxyethyl ethers to ynamides was developed to form six, seven-, and eight-membered cyclic ethers. These reactions reached completion within short reaction times (3 s to 3 h) at room temperature, and the cyclized products were obtained in good to quantitative yields. This is the first report of the construction of medium-sized oxacycles resulting from the iodocyclization of ynamides.

Geosynthetic clay liners (GCLs), used to repair small earth dams, are typically installed with the GCL panel placed parallel to the upstream slope of the dam or on the surface of benches cut into the upstream side of the earth dam fill. While the former requires less earthwork, leading to a more cost-effective and rapid construction, it can potentially introduce a plane of weakness if the interface shear strength between the GCL and the cover soil is less than the shear strength of the cover soil. The inclusion of benches in the upstream slope of an earth dam can potentially be an effective strategy for reducing the significance of this preferential failure plane, resulting in an increased seismic performance during earthquakes. However, the expected increase in seismic performance has not yet been quantified in large-scale shaking table tests. In this study, a full-scale shaking table test on an earth dam with a GCL installed parallel to the upstream slope of the dam is reported and compared to previously published results from tests on an identical earth dam with the GCL placed in the benched configuration under the same seismic boundary conditions. The results indicate that, for the configuration tested, the seismic deformation of the benched installation was half of that of the earth dam with the GCL installed parallel to the slope, providing significant motivation for adopting the benched installation method.

It has been shown that significant reduction of «carbon trace» in construction technology is achieved by production of clinker-effective concretes based on composite Portland cements. Studies have shown that uneven distribution of grain fractions of the filler mix and their increased specific surface area lead to growth of water demand, stratification, bleeding in the concrete mix and a decrease in concrete strength. To achieve higher grain packing density, an approach based on optimizing particle size distribution in the concrete mix components was implemented. It was found that increased early strength of concretes based on low-emission composite cements is achieved by introduction of polycarboxylate (PCE) superplasticizers and alkaline-sulfate activation. To establish connection between environmental and technical properties of concretes, clinker efficiency in concrete was determined. An increase in strength of modified concrete based on composite Portland cement CEM II/B-M 32.5 R (clinker factor 0.65) create the possibility for a significant reduction of specific consumption of clinker per unit strength, up to 4.5…3.0kg/(m3MPa); accordingly, CO2intensity 3.9...2.6kg CO2/(m3MPa). Significant intensification of the processes of early structure formation in nanomodified clinker-efficient concretes is ensured by a comprehensive approach: optimization of the component mix, introduction of the PCE superplasticizer and nanomodifiers. Using the laser diffraction method, it was proved that main contribution to development of specific surface of the nanomodified cementing matrix is made by ultrathin particles (Kisa=761.2μm–1vol.%) of nano-SiO2. It was established that synergistic combination of mineral additives in composite Portland cement and complex nano-SiO2+C-S-H-PCE nanomodifier provide increased early strength (after 12hours –Rc=6.4MPa) and obtaining rapid hardening concrete class C50/60 (fcm2/fcm28=0.51). Thus, there are reasons to argue that it is advisable to develop nanomodified clinker-efficient concretes in order to ensure rapid construction and solve problems connected with necessity of implementation of a strategy of low-carbon development

Precast segmental bridge columns (PSBC) have been gradually used in various bridge engineering for rapid construction. But current applications are mainly limited to low seismic areas due to the lack of energy dissipation capacity. In this study, the external self-centering energy dissipation device (SCEDD) was applied to improve the seismic capacity of PSBC. The refined solid finite element model was established and tested based on ABAQUS platform. The effects of four parameters of SCEDD, i.e., connection mode, nominal yield force, stiffness of disc springs and whether to install SCEDD at the bottom of the pier, were systematically discussed by quasi-static analysis. The results show that, the ductility of the PSBC can be improved by using hinged SCEDD in comparison with the rigid connection. However, two connection modes have no effects on the maximum strength and initial stiffness of the pier. Moreover, increasing the nominal yield force of SCEDD and the stiffness of disc springs can obviously reduce the ductility of the PSBC. Meanwhile, the potential plastic hinge region moves up. Furthermore, the installation of SCEDD can enhance the energy dissipation capacity of the PSBC, but is still insufficient compared with the cast-in-place (CIP) pier.

Rapid global infrastructural developments and advanced material science, amongst other factors, have escalated the demand for concrete. Cement, which is an integral part of concrete, binds the various individual solid materials to form a cohesive mass. Its production to a large extent emits many tons of greenhouse gases, with nearly 10% of global carbon (IV) oxide (CO2) emanating from cement production. This, coupled with an increase in the advocacy for environmental sustainability, has led to the development of various innovative solutions and supplementary cementitious materials. These aims to substantially reduce the overall volume of cement required in concrete and to meet the consistently increasing demand for concrete, which is projected to increase as a result of rapid construction and infrastructural development trends. Palm oil fuel ash (POFA), an industrial byproduct that is a result of the incineration of palm oil wastes due to electrical generation in power plants has unique properties, as it is a very reactive materials with robust pozzolanic tendencies, and which exhibits adequate micro-filling capabilities. In this study, a review on the material sources, affecting factors, and durability characteristics of POFA are carefully appraised. Moreover, in this study, a review of correlated literature with a broad spectrum of insights into the likely utilization of POFA-based eco-friendly concrete composites as a green material for the present construction of modern buildings is presented.

Building density parameter is one of the main indicators of urban monitoring. The accurate and rapid monitoring of building density changes can provide an important basis for urbanization management. It is of great significance to extract building density using dual-polarimetric Sentinel-1 SAR data which provides a short revisit period and a wide coverage. Therefore, this paper proposes a monitoring method of urban building density change based on dual-polarimetric Sentinel-1 data, integrating dual polarization information and texture features. Firstly, a dual polarimetric Sentinel-1 building index is constructed by analyzing the descriptive effects of SAR images on buildings. Then, the building index is used to monitor the change of building density. The experimental results show the effectiveness and practicality of this method by using the dual-polarimetric Sentinel-1 SAR data of Wuhan from 2018 to 2020. The experiments on the Huoshenshan and Leishenshan hospital before and after the construction during the COVID-19 pandemic can also prove the short-term monitoring ability of Sentinel-1 satellite in the rapid construction and expansion of urban areas.

Due to the increasing use of rapid construction methods and the challenges of maintaining construction schedules, a growing demand exists for procedures that can assure quality of work without sacrificing the pace of construction. The quality control of construction materials specifically, the mechanical properties of concrete are among the most important concerns in today’s construction industry. In the present study, the correlation between fiber-reinforced concrete’s compressive strength and dynamic modulus to its ultrasonic pulse velocity is investigated at early ages up to 7 days after mixing. An experimental program involving 189 FRC specimens were designed containing different types of structural fibers, fiber volume fractions, and water-to-cement ratios. Mathematical equations were developed to predict the early-age compressive strength and dynamic modulus of four different types of fiber-reinforced concrete based on ultrasonic pulse velocity. The predicted compressive strength and dynamic modulus from the proposed equations showed good agreement with the measured ones., Debido al aumento del empleo de métodos rápidos de construcción y los desafíos de mantener los calendarios de construcción, ha aumentado la demanda de procedimientos que permitan asegurar la calidad del trabajo sin sacrificar el ritmo de producción. Dentro del control de calidad de los materiales de construcción, las propiedades mecánicas del hormigón se encuentran entre las preocupaciones más importantes. En este estudio se investiga la correlación entre la resistencia a la compresión y el módulo dinámico del hormigón reforzado con fibras, con la velocidad de pulso ultrasónico a edades tempranas hasta 7 días después del amasado. Para ello se diseñó un programa experimental que involucró 189 muestras de HRF que contenían diferentes tipos de fibras estructurales, fracciones de volumen de fibra y relaciones agua/cemento. Se desarrollaron ecuaciones matemáticas para predecir la resistencia a la compresión y el módulo dinámico a edades tempranas de cuatro tipos diferentes de hormigón reforzado con fibras, en función de la velocidad del pulso ultrasónico. Tanto la resistencia a la compresión como el módulo dinámico pronosticados a partir de las ecuaciones propuestas mostraron una buena correlación con las medidas experimentales llevadas a cabo.

In view of the existing hardware-in-the-loop simulation (HILS) test system is customized design, there are many problems, such as long development cycle, consumption of resources, difficult to transplant and expand, etc. The research of HILS universal technology is carried out, and a general platform of HILS for integrated design is designed and developed, which can provide an integrated organizational structure and universal support platform for HILS, realize the rapid construction of the HILS test system, and effectively improve the portability and scalability of the HILS test system.

Traditional anthropometric evaluation needs professional measuring tools and operations, which is time- consuming, expensive, and not suitable for virtual try-on. As the mobile internet develops, the issue of human body reconstruction toward virtual try-on needs to be solved. This paper proposes a rapid human body reconstruction method for virtual try-on based on Multidimensional Dense Net (MDD-Net) on mobile terminal. MDD-Net takes the input of fusion features acquired by mobile as input and outputs 3D human body model to mobile supporting for virtual try-on. In the learning fuzzy anthropometric feature module, the example-guided fuzzy anthropometric feature matrix is acquired and default coding elements are interpolated. In the learning multi-perspective silhouette feature module, the fine human body shape features are learned based on DenseNet201. A corresponding fusion feature data set based on SMPL also is generated for MDD-Net training. In the experiments, without append fault-tolerant training samples, on the segmentation noise, nonstandard pose, and perspective error test set, the predicted accuracy of MDD-Net is improved by 13.34%, 55.77%, 34.6% and 43.4%, 37.2%, 9.0% respectively compared to Hs-Net and BfSNet proving its robust with the impact of uncertain positions and poses. And MDD-Net has a small error and standard deviation on critical anthropometric features explaining the effectiveness of our method.

A Bronsted acid catalyzed cascade benzannulation strategy for the one-pot synthesis of densely populated poly-aryl benzo[a]carbazole architectures is disclosed from easily affordable fundamental commodities. The efficacy of this technique was further validated via the concise synthesis of structurally unique carbazole based poly-aromatic hydrocarbons. Furthermore, the photo-physical properties of the synthesized compounds are thoroughly investigated.

The rapid construction of emergency hospitals in areas with a severe COVID-19 outbreak was one of the effective ways to contain and fight the pandemic. However, such rapid construction mega...

The technology in modern era and rapid construction sector has made welding an important role in the field of metal engineering and repair. Therefore, the technology in the construction sector, especially in the engineering sector, requires a welding element. Welding is used to combine with metal. Making this connection requires high skill for welder in order to obtain a good quality connection. The aim of this study was to determine the quality of a good welding result using the design of experiment method by looking at the control factor of the electrode, welding amperage, welding method, plate thickness, and welding speed. In addition to control factors, there are also use noise factors such as skill, cleanliness of work pieces, and distance between work pieces. The results of the experiments are based on weld defect criteria and the DOE method with ANOVA calculations, the best welding results are in trial no 7 with an average value of 0.22. Meanwhile, the results of the experiment with welding defects is trial experiment no 2 with a value of 0.64. The factors that influence the quality of the welds are plate thickness, welding amperage, electrodes, and welding method. Meanwhile, the welding speed factor is a factor that does not significantly affect the weld quality.

Based on engineering examples, the paper carried out research on the rapid construction technology of high piers in mountainous areas, and used unscented Kalman filter technology to eliminate the influence of measurement factors, man-made construction factors, and structural nonlinearities on the pre-deflection. The research results show that this technology can significantly improve the verticality of ultra-high piers in mountainous areas and has important application value.

Purpose The Southern African Institute of Steel Construction has developed a novel cellular beam structure (CBS) for multi-storey buildings that is entirely devoid of concrete. Channel sections between the cellular beams support a complex sandwich flooring system, which contains a fire-resistant ceiling board, metal sheeting, an interior fibre-cement board and an access-flooring system. As for all structures, the CBS requires a fire rating. This paper aims to investigate the thermal behaviour of the CBS using numerical modelling and experimental fire testing, as it has a unique setup. Design/methodology/approach Experimental fire tests on the flooring system were conducted to validate finite element models, which were developed in ABAQUS. These models were then extended to include floor beams and the structural steelwork. Findings Good correlations were found between the experimental and numerical results, with temperature variations typically in the range of 0-5%, although with localised differences of up to 20%. This allowed larger finite element models, representing the sandwich floor system of the CBS, to be developed and analysed. A 1-hour rating can be obtained by the system in terms of insulation and integrity requirements. Practical implications The CBS allows for more economical steel structures, due to the rapid construction of its modular panels. A suitable fire resistance will ensure the safety of the occupants and prevent major structural damage. Steelwork and flooring temperatures are determined which has allowed for global structural analyses to be carried out. Originality/value The originality of this study lies in thermal analysis and testing of a new cellular beam flooring system, through determining behaviour in fire, along with beam temperatures.

Accelerated Bridge Construction (ABC) offers advantages such as rapid construction, limited traffic disruption, fast project delivery, cost savings for the formwork, more accuracy in construction due to prefabrication, better quality control, higher durability, reduced weight of the bridge structure, enhanced safety, and less environmental impacts. ABC has been successfully deployed in low seismic regions. However, given the uncertainty about the adequate performance of connections between precast elements, application of ABC in high seismic regions has been limited. The research investigates the use of two types of emulative connections in a precast bent. The column-to-footing connection consists of member socket, while the column-to-cap beam connection is grouted ducts. These connections intend to emulate the traditional formation of plastic hinges in the bridge columns during an earthquake. A half-scale specimens with emulative connections was tested under quasi-static cyclic loading. Experimental results showed adequate seismic performance of the specimen compared to cast-in-place construction.

Cross-laminated timber (CLT) is a bio-based building material that enables rapid construction and buildings with low embodied energy. Despite its comparative maturity in European markets, relatively little information regarding process design and economics for the manufacture of cross-laminated timber is available in the literature. Two techno-economic analyses were conducted to quantify the mill-gate cost of cross-laminated timber. The cross-laminated timber manufacturing process was described, and costs were analyzed for two facility scales. Cross-laminated timber produced at the large-scale facility using lumber priced at an average value for the northwest United States has a minimum selling price of $536/m3. Sensitivity analyses were used to define the impact of plant size, asset utilization, lumber price, plant capital cost, material waste, and other variables on minimum selling price. The cost of cross laminated timber rises quickly when a facility is not fully utilized. The second-ranking cost controlling variable is lumber price, while energy prices have minimal influence. The price of cross laminated timber can be optimized by locating a facility near low-cost lumber. The lowest-price region analyzed was the southeast United States using Southern Pine, which reduced the cost of cross laminated timber to $518/m3.

With the advantages of a simple structure and rapid construction, the rigid netting barrier (RNB) exerts a good obstruction effect on granular flow and is a common engineering measure used to prevent geological disasters in the form of granular flows. However, due to the limitations of current measuring and testing techniques, it is difficult to obtain an accurate measurement of the granular flow velocity and the impact force of granular flow on the mesh structures that are of primary concern in the design of protective structures. To study the characteristics of the obstruction process of RNBs toward granular flow, a typical impact experiment involving granular flow was numerically simulated by the discrete element method, and the correctness and effectiveness of the calculation method were also verified. On this basis, the discrete element method was applied to simulate the obstruction process affecting granular flow under different RNB setting conditions, and the calculation results clearly present the phenomena that occur during the obstruction process of RNBs toward granular flow, such as “run-up,” “overflow,” “passing-through,” and “grain-size segregation.” By analyzing the effects of these phenomena on the obstruction efficiency and the time history of the forces acting on the RNB, the rational setting of an RNB was further discussed. This study can provide a reference for the engineering application of RNB.

A novel precast concrete beam–column connection locally post-tensioned using arc-shaped prestressing bars was proposed for satisfactory seismic performance and rapid construction. Three full-scale cruciform specimens, including one monolithic reference specimen, were tested under reversal cyclic loadings to evaluate the seismic behaviours. Grade 630 steel rods and high-strength deformed steel rebars were used for the arc-shaped prestressing bars in the precast specimens. The results show that the proposed precast connection presents an acceptable seismic performance and that the structural details should be ameliorated to improve the energy dissipation capacity. The design philosophy of strong column-weak beam is applicable to the new precast system. Finally, a strut-and-tie model was developed to investigate the force transfer mechanism of the novel precast connection.

A protective structure should be sufficiently resilient to protect its occupants from the harmful effects of an impact or explosion. In many instances, protective structures are also required to be assembled quickly, and be cost-effective. Steel-concrete-steel (SCS) sandwich structures combine the benefits of steel; ductility and anti-scabbing, and concrete; energy absorption and rigidity. Despite these favourable characteristics, the performance of profiled-plate steel-concrete-steel structures under blast and impact loads has yet to be studied in detail. This article presents the results from a numerical study investigating the efficacy of a newly proposed profiled-plate arched steel-concrete-steel structure under the loading from an extremely near-field high explosive detonation. It is observed that as arch thickness (concrete infill depth) increases, a greater proportion of energy is absorbed through concrete crushing and a larger concrete mass is mobilised. It is shown that a 240 mm arch thickness is adequate to resist the blast load from a 5.76 kg TNT charge, therefore proving the suitability of the proposed protective structure.