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A novel prefabricated segmental guardrail is proposed to facilitate connections between guardrails and between guardrails and bridge decks by casting ultrahigh-performance concrete (UHPC) joints in situ. Through finite element crash simulation analysis of three types of vehicles and crash tests of real vehicles, the prefabricated segmental guardrail with a UHPC connection was systematically evaluated in terms of its energy-absorbing capacity, vehicular acceleration, post-impact trajectory of the impacting vehicle, and behaviour of the guardrail upon impact. During the evaluation process, performance comparisons of the prefabricated segmental guardrails are made with the monolithic concrete guardrails. The results indicate that the performance of the prefabricated segmental guardrail with a UHPC connection was superior to that of the conventional concrete monolithic guardrails: it exhibited a higher level of crash performance, the occupants of the impacting vehicle were better protected, and the impacting vehicle exhibited better post-collision stability. Finally, the convenience of the prefabricated segmental guardrails with UHPC connections was proven in practical engineering applications. [ABSTRACT FROM AUTHOR]

The narrow-width steel box girder is an important type of steel–concrete composite bridge structure, which is usually composed of reinforced concrete wing plates, narrow steel boxes partially injected with concrete, and shear connectors that promote shear force transfer. The utilization of narrow-width steel box girders, augmented by partially filled concrete, embodies the synthesis of steel and concrete elements, fostering structural efficiency. Moreover, its attributes, including reduced structural weight, diminished vertical profile, enhanced load-bearing capacity, and augmented stiffness, have prompted its gradual integration into bridge engineering applications. In this study, the calculated values of shear strength under three current design codes were reviewed, and the shear failure phenomena and its determinants of narrow-width steel box–ultra-high-performance concrete (UHPC) composite beams under negative bending moment conditions were investigated, which were mainly determined by shear span ratio, concrete wing plate, UHPC steel fiber content, UHPC plate thickness, and transverse partition inside the box. Concurrently, this paper evaluates two innovative structural designs, including a double-narrow steel box girder and a three-narrow steel box girder. In addition, strategies to reduce crack formation under the negative bending moment of long-span continuous narrow and wide box girder abutments are discussed, and we show that this measure can effectively control the formation of cracks to support the negative bending moment zone. At the same time, the scope of the application of a narrow-width steel box girder composite bridge is reviewed, and the conclusion is that a narrow-width steel box girder is mainly used in small-radius flat-curved bridges or widened-ramp bridges with a span of 30 m or more in interworking areas and in the main line with a 60–100 m span in mountainous or urban areas. Finally, the research direction of the shear resistance of the UHPC–narrow steel box girder under negative bending moments is proposed. [ABSTRACT FROM AUTHOR]

Abstract A novel prefabricated segmental guardrail is proposed to facilitate connections between guardrails and between guardrails and bridge decks by casting ultrahigh-performance concrete (UHPC) joints in situ. Through finite element crash simulation analysis of three types of vehicles and crash tests of real vehicles, the prefabricated segmental guardrail with a UHPC connection was systematically evaluated in terms of its energy-absorbing capacity, vehicular acceleration, post-impact trajectory of the impacting vehicle, and behaviour of the guardrail upon impact. During the evaluation process, performance comparisons of the prefabricated segmental guardrails are made with the monolithic concrete guardrails. The results indicate that the performance of the prefabricated segmental guardrail with a UHPC connection was superior to that of the conventional concrete monolithic guardrails: it exhibited a higher level of crash performance, the occupants of the impacting vehicle were better protected, and the impacting vehicle exhibited better post-collision stability. Finally, the convenience of the prefabricated segmental guardrails with UHPC connections was proven in practical engineering applications.

In this study, the structural details of a hinge connection for steel girder segments were developed to improve the process of rapid and easy construction. In the connector developed in this study (referred to as the "speedBridge" hereafter), the compression load exerted on the upper flange is resisted by two bearing blocks in contact with each other, and the tensile force on the bottom flange is resisted by the hinge structure installed at the lower part of the steel girder. The structural behavior of the developed connection was investigated experimentally. It was shown that the developed connection details could develop an excellent connection plastic rotation of 5% rad without fracture. The test specimen developed initial stiffness in accordance with elementary beam theory for a supported beam. The maximum load reached 110% of the plastic moment of the beam. Finite element analysis was conducted to comprehend the load transfer path, and the results demonstrated that the hinge connection exhibited sufficient stiffness and strength, exceeding the bending capacity of the beam under tension without any signs of the failure modes considered in the design procedure. [ABSTRACT FROM AUTHOR]

The narrow-width steel box girder is an important type of steel–concrete composite bridge structure, which is usually composed of reinforced concrete wing plates, narrow steel boxes partially injected with concrete, and shear connectors that promote shear force transfer. The utilization of narrow-width steel box girders, augmented by partially filled concrete, embodies the synthesis of steel and concrete elements, fostering structural efficiency. Moreover, its attributes, including reduced structural weight, diminished vertical profile, enhanced load-bearing capacity, and augmented stiffness, have prompted its gradual integration into bridge engineering applications. In this study, the calculated values of shear strength under three current design codes were reviewed, and the shear failure phenomena and its determinants of narrow-width steel box–ultra-high-performance concrete (UHPC) composite beams under negative bending moment conditions were investigated, which were mainly determined by shear span ratio, concrete wing plate, UHPC steel fiber content, UHPC plate thickness, and transverse partition inside the box. Concurrently, this paper evaluates two innovative structural designs, including a double-narrow steel box girder and a three-narrow steel box girder. In addition, strategies to reduce crack formation under the negative bending moment of long-span continuous narrow and wide box girder abutments are discussed, and we show that this measure can effectively control the formation of cracks to support the negative bending moment zone. At the same time, the scope of the application of a narrow-width steel box girder composite bridge is reviewed, and the conclusion is that a narrow-width steel box girder is mainly used in small-radius flat-curved bridges or widened-ramp bridges with a span of 30 m or more in interworking areas and in the main line with a 60–100 m span in mountainous or urban areas. Finally, the research direction of the shear resistance of the UHPC–narrow steel box girder under negative bending moments is proposed.

In this study, the structural details of a hinge connection for steel girder segments were developed to improve the process of rapid and easy construction. In the connector developed in this study (referred to as the “speedBridge” hereafter), the compression load exerted on the upper flange is resisted by two bearing blocks in contact with each other, and the tensile force on the bottom flange is resisted by the hinge structure installed at the lower part of the steel girder. The structural behavior of the developed connection was investigated experimentally. It was shown that the developed connection details could develop an excellent connection plastic rotation of 5% rad without fracture. The test specimen developed initial stiffness in accordance with elementary beam theory for a supported beam. The maximum load reached 110% of the plastic moment of the beam. Finite element analysis was conducted to comprehend the load transfer path, and the results demonstrated that the hinge connection exhibited sufficient stiffness and strength, exceeding the bending capacity of the beam under tension without any signs of the failure modes considered in the design procedure.

Conventional hot mix asphalt overlaying on trench infrastructure typically necessitates extended cooling times for further works and can have adverse effects on buried components, such as electricity cables and hot water pipes. Therefore, this research aims to investigate the use of warm guss mastic asphalt (at an installation temperature of 160 °C) as an overlaying material for mini-trenches, which can reduce the cooling time required for traffic opening and improve the efficiency of the construction process. This research involved two stages: first, lab testing and related research results were used to generate the thermal conductivity and specific heat necessary for simulation work. Second, a finite element model analysis was conducted to evaluate the thermal transmission of the overlaying surface and the buried conduit based on the summer pavement temperature distribution through the Korean Pavement Research Program. Afterward, the field test bed was constructed to verify the simulation. The results indicate that the optimal thickness of the overlaying material and the concrete covering should be designed to ensure thermal durability and meet traffic opening requirements. The overlaying depth of the mini trench using warm mix guss mastic asphalt should be less than 100 mm to meet with the traffic opening time, while the thickness of the concrete covering should be designed to be more than 100 mm to ensure thermal durability. Additionally, the findings suggest that the application of warm guss asphalt could reduce the opening time by 30 min to 1 h and 25 min compared to conventional hot guss asphalt materials. When the pavement surface temperature for the traffic opening is controlled at 50 °C, the asphalt mixture requires at least 2 h to 5 h to meet the cooling criteria for traffic opening, respectively. Overall, this research confirms the potential benefits and optimal use of warm guss mastic asphalt in the construction process of mini-trenches. [ABSTRACT FROM AUTHOR]

As a temporary means of water transportation, floating bridges play an important role in the military and other fields. However, traditional floating bridges have limitations such as large size, heavy weight, and slow construction time. In this paper, we propose a rigid-flexible composite folding floating bridge. The main structure of the floating bridge consists of three layers: the bridge deck, airbag, and water bag. The floating bridge units are connected by flexible connectors to allow for pre-connection and folding of the bridge, reducing storage and transportation space, and improving construction efficiency. The proposed floating bridge also has a complete engineering application design and has been checked for safety and reliability (including the strength, buoyancy, and bearing capacity of the connections). We used AQWA software to simulate and analyze the anchorage scheme of the floating bridge and its response to wave loads and conducted a ballast test on a floating bridge model to verify its feasibility as a main bearing body. The results show that the floating bridge we designed has the advantages of being lightweight, having fewer consumables, having a small storage and transportation space, and being able to be constructed quickly. [ABSTRACT FROM AUTHOR]

Freshly paved asphalt must be sufficiently warm before it can be trafficked to prevent premature failure. In countries with high air ambient temperature, the newly laid asphalt temperatures reduce slowly; thus, it requires lengthy periods to reach the opening-to-traffic asphalt temperature. Some contractors practice spraying water onto the freshly paved asphalt to accelerate the cooling time, so the new sections can be quickly opened to traffic. However, no particular research has been performed regarding this practice. This study aims to investigate the effectiveness of spray water cooling and examine the potential detrimental effects on the asphalt material properties. For this purpose, laboratory temperature measurements and heat transfer analyses of natural cooling and water spray cooling were performed. In addition, Cantabro and indirect tensile strength (IDT) testing were carried outto investigate the possible drawbacks of water. The results indicate the water spray application onto newly laid asphalt pavement does not necessarily adversely affect the asphalt durability (resistance to cohesion loss) and or the moisture damage of asphalt pavement. However, it is likely to be of limited value in accelerating the cooling of overlays, except when they are relatively thin. [ABSTRACT FROM AUTHOR]

The reverse genetics system of the Newcastle disease virus (NDV) has provided investigators with a powerful approach to understand viral molecular biology and vaccine development. It has been impressively improved with modified strategies since its first report, but it still poses some challenges. Most noteworthy, the genome complexity and length made full-length error-free cDNA assembly the most challenging and time-consuming step of NDV rescue. In the present study, we report a rapid full-length NDV genome construction with only a two-step ligation-independent cloning (LIC) strategy, which could be applied to distinct genotypes. In this approach, the genome of NDV was divided into two segments, and the cDNA clones were generated by RT-PCR followed by LIC. Subsequently, the infectious NDVs were rescued by co-transfection of the full-length cDNA clones and supporting plasmids expressing the NP, P, and L proteins of NDV in BHK-21 cells. Compared with the conventional cloning approaches, the two-step cloning method drastically reduced the number of cloning steps and saved researchers a substantial amount of time for constructing NDV infectious clones, thus enabling a rapid rescue of different genotypes of NDVs in a matter of weeks. Therefore, this two-step LIC cloning strategy may have an application to the rapid development of NDV-vectored vaccines against emerging animal diseases and the generation of different genotypes of recombinant NDVs for cancer therapy.

Conventional mortar cemented anchors cannot meet the needs for landslide emergency management, as they can withstand loads only after mortar curing for 14–28 days. This study developed a multi-segment expanded anchor (MSEA) that expands using a sliding mechanism and rapidly bears loads using multiple load-bearing bodies by the frictional drag along the perforated wall, and the reaction force of the underreams' platforms. Field tensile tests without grouting and the secondary tensile tests of six MSEAs, each with a length of 23 m, were carried out. The field tests show that the installed load-bearing bodies expanded steadily when the MSEAs were tensioned without grouting. In hard sandstones, the initial tensile force of each load-bearing body exceeded its design value of 150 kN, and the initial bearing capacity of each MSEA was greater than 300 kN, which exceeded the bearing capacity of the existing anchors regardless of grouting. The secondary tensile tests of the MSEAs were conducted after they were grouted for three days, and their lock-off load was greater than their design value of 600 kN. Based on the elastic mechanics and the stress process of the MSEAs, this study derived the theoretical equations of the ultimate bearing capacity of the MSEAs without grouting. The results calculated using the theoretical equations were roughly consistent with the field test results of the ultimate bearing capacity. [ABSTRACT FROM AUTHOR]

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 asphalt airport runway overlay would avoid early damage – while also minimising the disruption to the airport service due to prolonged runway closure in a busy airport. This study aims to investigate the allowable traffic-opening temperature of freshly paved asphalt during nighttime construction through a series of laboratory tests with regard to asphalt rutting and interface shear failure potential. Additionally, a transient heat transfer model is developed to study the cooling response of freshly laid asphalt and, along with stress analysis, used to deduce the effect of selected critical traffic opening to traffic on airport closure. The results suggest that mixtures with polymer-modified bitumen (PMB) can be re-opened to air traffic at a considerably higher temperature (up to 80°C) than conventional traffic-opening temperature as set by many agencies (60°C). This result encourages airport authorities and agencies to be more adaptive with the traffic-opening temperature specification, particularly for asphalt with PMBs. For the cases studied, raising the critical trafficking temperature would reduce the runway/airport closure during nighttime construction by 17–114 minutes (26–63% reductions). [ABSTRACT FROM AUTHOR]

As a temporary means of water transportation, floating bridges play an important role in the military and other fields. However, traditional floating bridges have limitations such as large size, heavy weight, and slow construction time. In this paper, we propose a rigid-flexible composite folding floating bridge. The main structure of the floating bridge consists of three layers: the bridge deck, airbag, and water bag. The floating bridge units are connected by flexible connectors to allow for pre-connection and folding of the bridge, reducing storage and transportation space, and improving construction efficiency. The proposed floating bridge also has a complete engineering application design and has been checked for safety and reliability (including the strength, buoyancy, and bearing capacity of the connections). We used AQWA software to simulate and analyze the anchorage scheme of the floating bridge and its response to wave loads and conducted a ballast test on a floating bridge model to verify its feasibility as a main bearing body. The results show that the floating bridge we designed has the advantages of being lightweight, having fewer consumables, having a small storage and transportation space, and being able to be constructed quickly.

Conventional hot mix asphalt overlaying on trench infrastructure typically necessitates extended cooling times for further works and can have adverse effects on buried components, such as electricity cables and hot water pipes. Therefore, this research aims to investigate the use of warm guss mastic asphalt (at an installation temperature of 160 °C) as an overlaying material for mini-trenches, which can reduce the cooling time required for traffic opening and improve the efficiency of the construction process. This research involved two stages: first, lab testing and related research results were used to generate the thermal conductivity and specific heat necessary for simulation work. Second, a finite element model analysis was conducted to evaluate the thermal transmission of the overlaying surface and the buried conduit based on the summer pavement temperature distribution through the Korean Pavement Research Program. Afterward, the field test bed was constructed to verify the simulation. The results indicate that the optimal thickness of the overlaying material and the concrete covering should be designed to ensure thermal durability and meet traffic opening requirements. The overlaying depth of the mini trench using warm mix guss mastic asphalt should be less than 100 mm to meet with the traffic opening time, while the thickness of the concrete covering should be designed to be more than 100 mm to ensure thermal durability. Additionally, the findings suggest that the application of warm guss asphalt could reduce the opening time by 30 min to 1 h and 25 min compared to conventional hot guss asphalt materials. When the pavement surface temperature for the traffic opening is controlled at 50 °C, the asphalt mixture requires at least 2 h to 5 h to meet the cooling criteria for traffic opening, respectively. Overall, this research confirms the potential benefits and optimal use of warm guss mastic asphalt in the construction process of mini-trenches.

The results achieved by the VNIIG in the field of concrete technology and concreting are briefly described. Some latest developments and experience of their application in various sectors of construction are described. [ABSTRACT FROM AUTHOR]

Conventional mortar cemented anchors cannot meet the needs for landslide emergency management, as they can withstand loads only after mortar curing for 14–28 days. This study developed a multi-segment expanded anchor (MSEA) that expands using a sliding mechanism and rapidly bears loads using multiple load-bearing bodies by the frictional drag along the perforated wall, and the reaction force of the underreams’ platforms. Field tensile tests without grouting and the secondary tensile tests of six MSEAs, each with a length of 23 m, were carried out. The field tests show that the installed load-bearing bodies expanded steadily when the MSEAs were tensioned without grouting. In hard sandstones, the initial tensile force of each load-bearing body exceeded its design value of 150 kN, and the initial bearing capacity of each MSEA was greater than 300 kN, which exceeded the bearing capacity of the existing anchors regardless of grouting. The secondary tensile tests of the MSEAs were conducted after they were grouted for three days, and their lock-off load was greater than their design value of 600 kN. Based on the elastic mechanics and the stress process of the MSEAs, this study derived the theoretical equations of the ultimate bearing capacity of the MSEAs without grouting. The results calculated using the theoretical equations were roughly consistent with the field test results of the ultimate bearing capacity.

An experiment on high‐strain hardening ultra‐high‐performance concrete (UHPC) stitching joints was conducted based on the bridge‐stitching project of Jiyang viaduct, Shanghai. In this experiment, asymmetrical loading was used to simulate the bridge differential settlement caused by soil settlement. The experimental results showed that the entire process could be divided into three stages: elastic stage, cracks developing stage, and failure stage. During these stages, cracks appeared at the bottom of the UHPC slab. Then, many microcracks appeared at the side of the UHPC slab. These microcracks appeared in the form of microcrack clusters, and the width of these cracks increased slowly. It indicated that UHPC had good crack‐control ability. Finally, the main crack appeared at the bottom of the UHPC slab, and the transverse reinforcements yielded. It indicated that the reinforcement layout met the requirements of the failure mode of the specimen. For further analysis, the finite‐element model (FEM) was established. And the results showed that the bending resistance of the joints could be effectively enhanced by increasing the free length of the joint or reducing the thickness of the joint. Based on this experiment and analysis, a nonconnected joint form between slabs and girders was put forward. And the detailed reinforcement scheme of this nonconnected joint form was given. This reinforcement scheme could serve as a reference for similar projects. [ABSTRACT FROM AUTHOR]

The concrete structure for liquefied natural gas (LNG) storage tanks is relatively simple but has a complicated construction procedure and takes a long time to construct. Also, because the inner tank cannot be constructed until the outer tank is finished, there are limitations to the current construction method in reducing the construction time. Therefore, a rapid method for LNG storage tank construction using precast concrete panels is proposed in this study to help shorten the construction time and improve quality control. The proposed method involves a change in the construction procedure. The precast concrete panels are used as the outer permanent form, and the wall liner is used as the inner permanent form for the outer tank wall. This is a new construction process that does not require installing and dismantling temporary forms. As a result, the inner and outer tanks can be simultaneously constructed once the self-standing wall liner is completed. [ABSTRACT FROM AUTHOR]

Asynchronous construction is a new construction method for composite girder bridges with corrugated steel webs. This new construction technology has multiple advantages over conventional cantilever construction technology, including a simple basket structure, low steel consumption, high material utilization, short construction period and superior stability. Herein, a 1:1 full-scale corrugated steel web model test is designed based on the Fenghua River Bridge, which is the longest span composite girder bridge with corrugated steel webs in China. This test analyzes the shear stress distribution of corrugated steel webs under the most unfavorable stress conditions and the ultimate bearing capacity of single corrugated steel webs under the most unfavorable load conditions during asynchronous construction. The deformation and stress conditions are measured to identify critical stress areas during construction. Additionally, the safety of each area during construction is verified to provide guidance for asynchronous construction plans for the same type of bridge structures. • A 1:1 full-scale test of a composite bridge with corrugated steel webs during asynchronous construction was performed. • The vertical deflection difference between adjacent sections should be considered to control the linear of the main girder. • A temporary horizontal support should be added to the corrugated steel webs to prevent the lateral deformation of the web. • The corrugated steel webs have sufficient safety factor during asynchronous construction. • The flange steel plates under loading points should be reinforced To prevent buckling. [ABSTRACT FROM AUTHOR]

Highlights • Fe@ Zeolite Imidazolate Framework-67 (Fe@ZIF-67) is prepared by a extremely simple method in aqueous solution. • The Fe@ZIF-67 is efficient adsorbent for removal of uranyl ions. • The Fe@ZIF-67 exhibites good performance at ambient temperature and acid aqueous. • The Fe@ZIF-67 can be rapid separated from aqueous solution by magnetic separation. • The Fe@ZIF-67 has potential applicability in the adsorption of uranyl ions from water. Abstract The novel Fe@ZIF-67 was utilized as a promising adsorbent for the adsorption and separation of U(VI) ions from aqueous solutions for the first time. The material performed potential adsorption capacity of 292.2 mg g−1 and an outstanding selectivity on U(VI) at pH = 4.5. Furthermore, the adsorption performance of this new adsorbent agreed well with the Langmuir, Freundlich isotherm and pseudo-first-order kinetic model. Given the advantages of this adsorbent such as high adsorption capacity, selectivity, and environment-friendly, it may be an outstanding candidate for the adsorption of U(VI) ions for practical application. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Prefabrication is a manufacturing process conducted at a specialized facility, in which various materials are joined to form a component part of the final installation. Prefabrication techniques have been progressively adopted in the construction industry in various countries. The demand was at its peak in the early 1970s in Eastern and Western Europe for the construction of new towns. Worldwide, the highest precast levels in 1996 were located in Denmark (43%), the Netherlands (40%), Sweden and Germany (31%). In Asia, the precast levels in Japan and Singapore were about 15% and 8%, respectively, recently, the use of prefabrication is further encouraged to increase productivity and build ability. In Syria too, the first residential project in Damascus: the establishment of 2400 housing units in the year (77-80). Except that the rate of construction pre-cast in Syria is still not exceed 2% of Building of reinforced concrete. In order to participate in the reconstruction of Syria, after the destruction and devastation caused by the war over four years, this search evaluates successful international experiences in rapid construction technique, and modeled system that could serve the current Syrian reality. Introduction of this technology as a new method in the world of construction in Syria requires a good base, relying on the availability of the necessary raw materials and nearness of work site, as well as the need to replace old technology into modern technology, and analyzing the economic, social, environmental criteria, to make the decision about the best solution. Cost and time will form the most important indicators that will be analyzed and calculated, before the final model mode, in order to be able to use this system later in Syrian construction companies.

Digital manufacturing has transformed many industries but has had only a limited impact in the construction sector. To capitalize on advanced manufacturing techniques, this paper introduces a radically new connection approach for gravity structural steel frames. The proposed intermeshed steel connection (ISC) exploits robotic abilities to cut structural steel member ends precisely to accelerate deployment and offer better disassembly options over existing approaches. Forces are transferred through common bearing surfaces at multiple contact points, and connections can be secured by small locking pieces. This paper introduces the geometry, manufacturing, and initial analysis and test results of the connection. The paper demonstrates the ability of the connection to (1) be manufactured within current industrial tolerances, (2) be erected and disassembled, and (3) perform at expected design levels.

Transverse block of a steel box girder viaduct can decrease the shear connection between the upper part and the lower part. As a consequence, deflection and deflection difference between blocks are significant, and the performance of weld seams and finished viaduct can be affected. To decrease the deflection of steel box blocks with an open section after transverse discretization, a piecewise uniform arrangement of temporary shear braces is proposed on condition that the total shear stiffness of the shear braces remains unchanged. First, the formulas for slip, axial force and deflection with a piecewise uniform arrangement of temporary shear braces are given, and the accuracy is verified by comparing the results with finite element method. The proposed formulas are applied to two field studies and the results show good agreement with measured data. Finally, the optimal arrangement of temporary shear braces was explored by the sequential quadratic programming optimization method. The deflection and the deflection difference at welding position are reduced significantly after bracing, and the optimal shear braces arrangement is to arrange the braces more at the ends of the blocks. [ABSTRACT FROM AUTHOR]

A new concept was developed to accelerate the construction of highway bridge bents, to improve their seismic resilience, and to make them more durable. On-site construction activities are accelerated by precasting the columns and cap beams and by using socket connections at the bottoms of the columns and grouted connections at the top. Unbonded pretensioning of the columns increases both the bridge's seismic resilience (through improved recentering) and its durability (through reduced cracking), whereas precasting improves quality control. Previous researchers have incorporated unbonded posttensioning into structural systems to reduce postearthquake residual displacements, but pretensioning is preferable in terms of construction convenience, speed, and quality control. Epoxy coating also adds corrosion resistance to the pretensioned strands. Two cantilever concrete subassemblies, representing the top and bottom connections for a column, were subjected to constant axial load and cyclic lateral loading. The tests demonstrated that the new system recenters better than does a comparable RC column. Furthermore, the inelastic action was restricted to the columns, thereby validating the capacity protection of the connection regions. [ABSTRACT FROM AUTHOR]

• Surface property of porous RHA support was tailored to enhance loading of hydrated salt PCM. • Solar thermal energy storage based on PCM was developed to cure concrete in cold climate. • Numerical method was proposed to guide reasonable design of thermal energy storage layer. • Rapid construction of concrete was achieved by solar thermal energy storage curing method. • Energy saving and emission reduction effects were remarkable. In this paper, a novel strategy of concrete curing was developed by solar thermal energy storage based on phase change material (PCM), in order to prevent concrete from frost damage at early age and promote the rapid growth of concrete strength in cold climate. This method utilized huge latent heat of thermal energy storage layer (TESL) containing PCM to achieve continuous curing of concrete at positive temperature, and transparent insulation layer (TIL) was set outside so that TESL can fully absorb a large amount of thermal energy through solar radiation to complete repeated phase transition between day and night. Moreover, a numerical method was proposed to guide the reasonable design of TESL under different climatic conditions and it turned out that the optimum thickness of TESL ranged from 0.87 cm to 4.86 cm. Experiment results indicated that concrete specimen cured by the novel curing strategy achieved an excellent curing temperature history and it took only 60 h to reach the design strength. In addition, economic evaluation results suggested low cost, prominent energy saving and emission reduction performance of the proposed curing method in the whole service cycle. This work provided new insights into an efficient and clean solution to achieving the rapid construction of concrete engineering in cold climate. [ABSTRACT FROM AUTHOR]

A simplified method validated by centrifuge tests is developed to estimate both the deformation and stability of soft ground improved by piles during the rapid construction of embankments. Furthermore, this method, which considers pile-soil interaction, is adopted to investigate the failure mechanism and performance of piles. It is determined that piles embedded in a stiff stratum may be subjected to a dual bending failure. The first failure may occur at the soft-stiff interface because of the embedment effect of the stiff stratum, while the second failure may take place at the upper part of the piles due to the inflexion effect of soft ground movements. A progressive bending failure of piles may also occur as the maximum bending moment of each pile varies with the pile location. The progressive failure could propagate from the piles beneath the embankment toe towards the embankment centre. In addition, the location, stiffness, and fixity of piles have a significant influence on the stability of soft ground. The piles beneath the embankment toe are key piles, and increasing the stiffness and enhancing the embedment of these piles could efficiently ensure the stability of soft ground. [ABSTRACT FROM AUTHOR]

The reverse genetics system of the Newcastle disease virus (NDV) has provided investigators with a powerful approach to understand viral molecular biology and vaccine development. It has been impressively improved with modified strategies since its first report, but it still poses some challenges. Most noteworthy, the genome complexity and length made full-length error-free cDNA assembly the most challenging and time-consuming step of NDV rescue. In the present study, we report a rapid full-length NDV genome construction with only a two-step ligation-independent cloning (LIC) strategy, which could be applied to distinct genotypes. In this approach, the genome of NDV was divided into two segments, and the cDNA clones were generated by RT-PCR followed by LIC. Subsequently, the infectious NDVs were rescued by co-transfection of the full-length cDNA clones and supporting plasmids expressing the NP, P, and L proteins of NDV in BHK-21 cells. Compared with the conventional cloning approaches, the two-step cloning method drastically reduced the number of cloning steps and saved researchers a substantial amount of time for constructing NDV infectious clones, thus enabling a rapid rescue of different genotypes of NDVs in a matter of weeks. Therefore, this two-step LIC cloning strategy may have an application to the rapid development of NDV-vectored vaccines against emerging animal diseases and the generation of different genotypes of recombinant NDVs for cancer therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yu, Zhang, Li, Yu, Jia, Yu, Chen, Chen and He.)

A new bridge system has been developed to (1) reduce on-site construction time by using precast components, (2) eliminate major earthquake damage by utilizing column rocking and confinement of the column ends with a steel tube, and (3) maintain the system functionality after a strong earthquake by minimizing residual drift through the use of pretensioned strands in the columns. Furthermore, it uses only conventional materials. This paper compares the shaking table performance of a quarter-scale, two-pan bridge constructed through the use of the new system with that of a conventional cast-in-place bridge with similar geometry tested in 2005. The new bridge system was constructed in approximately 20% of the time needed for the conventional cast-in-place system. In tests, the conventional bridge suffered major concrete cracking and spalling, whereas in the new system, damage to the concrete was only cosmetic. In the conventional bridge, the longitudinal bars buckled, and both the longitudinal and spiral reinforcement fractured, whereas in the new system, the damage to the reinforcement was limited to longitudinal bar fracture, and that occurred only under excitations much larger than the design-level motion. Furthermore, bar fracture in the new system could be delayed by increasing the unbonded length of the bars. The residual drift of the new system was essentially zero for all motions, whereas one of the exterior bents of the conventional bridge was so badly damaged and out of plumb that some of the supplemental mass on the bridge had to be removed, and testing was stopped shortly thereafter. [ABSTRACT FROM AUTHOR]

Bridge deck construction using stay-in-place (SIP) fiber-reinforced polymer (FRP) structural forms has shown promise as an efficient, rapid, and low-waste alternative to conventional methods. Several studies have shown that the load capacity of this system is typically governed by punching shear strength, although no design-oriented equations have yet been developed to predict failure load or deflection at service. In this paper, two simple design equations are proposed for the ultimate load and stiffness of concrete deck slabs with SIP FRP forms, derived from the results of a comprehensive parametric study using a rigorous finite-difference computer model that is readily available. The equations were then validated by using experimental results from a database of 52 tests reported in the literature including FRP SIP forms of several shapes, sizes, surface treatments, spliced connections, boundary conditions, environmental exposures, and loading protocols. The equations showed an average predicted-to-experimental nominal strength of 87% with a standard deviation of 19%. When applying the design code member resistance factor of 0.75 consistent with shear failure of FRP-reinforced decks, a conservative strength was predicted for the entire database. Stiffness, on the other hand, was less accurately predicted; however, the model provided reliable and accurate indication of whether deflection limit is satisfied or not. [ABSTRACT FROM AUTHOR]

A new bridge bent system has been developed to reduce on-site construction time, minimize residual displacements even after a large earthquake, and reduce seismic damage in comparison with conventional cast-in-place construction. Accelerated construction is achieved through the use of precast columns and cap beams that can be assembled quickly. Postearthquake residual displacements are reduced by pretensioning the columns with partially unbonded tendons. Damage in the columns is nearly eliminated by concentrating flexural deformations to specially detailed regions at the top and bottom of the columns. In this study, the seismic performance of the new systemwas evaluated with a multi-shaking table test of a quarter scale, two-span bridge at the Network for Earthquake Engineering Simulation (NEES) Earthquake Engineering Laboratory at the University of Nevada, Reno. The maximum displacements of the bents were similar to those expected for a conventional bridge through the 100% design-level event [peak ground acceleration (PGA) = 0.75 g]. Residual drift ratios never exceeded 0.2% up to the 221% design-level motion (PGA = 1.66 g). Damage to the column concrete was negligible; the columns would not need any repair after being subjected to the 100% design-level motion. The only structural damage to the bridge was the eventual fracture of the column's longitudinal reinforcement and bulging of the column's confining tube, both of which occurred at drift ratios of approximately 6%. These damage states could be delayed by increasing the debonded length of the deformed bar reinforcement at the ends of the columns and by using a thicker steel tube for the confining detail. [ABSTRACT FROM AUTHOR]

• Prefabricated base structure was proposed for rapid construction of urban roads. • Compared to traditional semi-rigid base, prefabricated base is easy to construct. • Prefabricated base provides better load-bearing capacity than semi-rigid base. With the expansion of urbanization and the increasing demand for rapid construction, prefabricated base structures have been effectively used in shortening the construction time of asphalt pavements. However, the existence of various joints between conventional prefabricated blocks reduces the overall load-bearing capacity of the base structure. To overcome this deficiency, this study proposes to design specific joints between the prefabricated blocks, which could ensure the durability and load-bearing capacity of the prefabricated base. To achieve this goal, the design parameters and evaluation indexes were firstly analyzed based on the finite element method. Secondly, the single factor analysis method was used to preliminarily analyze the influence of the inclination of the lateral surface of the base block, the base material and the joint shape on the evaluation indexes of the prefabricated base, providing data support for the multi-factor analysis. The representative combinations were then selected using an orthogonal experimental design approach. On the basis of range- and variance analysis, the influencing factors were analyzed significantly, and the design scheme of the prefabricated base joint was proposed. Finally, the load-bearing capacity of the prefabricated base structure was calculated and verified using the modified Benkelman beam method. The results indicate that the optimal design scheme of the prefabricated base is achieved when the depth of the transverse groove is 10 mm, the degree of lateral tilt of the base block is 0.25, the modulus of the mortar is 6 GPa, and the width of the joint is 30 mm. In summary, the proposed method can ensure the load-bearing capacity of the prefabricated base during the rapid construction of asphalt pavement. [ABSTRACT FROM AUTHOR]

Prefabricated bridge components are in increasing demand for accelerated bridge construction. Precasting eliminates the need for forming, casting, and curing of concrete on site, making bridge construction safer while improving quality and durability. This paper describes the development and implementation of a precast concrete bridge bent system suitable for accelerated bridge construction in high seismic zones, such as western Washington. At the base of the bent, the column is connected to a spread footing using a socket connection, while at the top the column is joined to the cap beam using bars grouted in ducts. In both cases the connection was verified by testing before the system was implemented on-site by the Washington State Department of Transportation. [ABSTRACT FROM AUTHOR]

Abstract: Virtual battlefield environment is the use of computer technology, graphics technology and virtual reality technology to the real battle space in the computer. As technology advances and development, virtual battlefield environment system has been applied more and more combat troops and combat command being. Virtual Battlefield Environment Simulation System is a system for the commander to provide a realistic battlefield environment to facilitate their understanding of the terrain, the battlefield awareness information. In this paper, two-dimensional battlefield maps based on MapObject structures and the construction of three-dimensional virtual battlefield environment problem, a second, three-dimensional virtual battlefield environment with the rapid construction techniques. Operational commanders can quickly build a virtual battlefield, not only from the macro real-time battlefield information and to grasp the battlefield situation, but also learned from the battlefield of detailed microscopic details. [Copyright &y& Elsevier]

A new beam-to-column connection has been developed for assembling precast concrete bridge bents in regions of high seismicity. The connection is made with a small number of large column bars, which are grouted into large corrugated-metal ducts embedded in the cap beam. Bents built with these connections can be erected quickly and permit generous construction tolerances. To evaluate the seismic performance of the proposed connection, lateral-load tests were performed on three manifestations of the connection, as well as on a comparable cast-in-place connection. The tests demonstrated that the force-displacement response and damage progression in the precast connection are similar to those of typical cast-in-place concrete connections. Deliberate partial debonding of the longitudinal reinforcement only slightly affected the force-displacement response and observed damage. [ABSTRACT FROM AUTHOR]

The article discusses the study which presents the transverse post-tensioning design and the details of precast/prestressed concrete adjacent box-girder bridges. It develops design charts for various combination of span length, bridge width, skew angle, and girder depth from the standard AASHTO specifications. It reveals the new interest in using adjacent box-girder bridges for rapid construction under the Federal Highway Administration.