Journal articles on the topic 'Concrete bridges – Design and construction – Mathematical models'
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Belostotsky, Alexander M., Pavel A. Akimov, Andrey A. Aul, Dmitry S. Dmitriev, Yulia N. Dyadchenko, Alexander I. Nagibovich, Konstantin I. Ostrovsky, and Andrey S. Pavlov. "Analysis of Mechanical Safety of Stadiums for the World Cup 2018." Scientific journal “ACADEMIA. ARCHITECTURE AND CONSTRUCTION”, no. 3 (September 27, 2018): 118–29. http://dx.doi.org/10.22337/2077-9038-2018-3-118-129.
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It is obvious that contemporary design and construction of unique buildings and structures is unthinkable without mathematical (numerical) and computer modelling and advanced analysis ofload-bearing structures under various kinds ofloads and impacts. One of the most ambitious and important construction projects is the uniquelarge-span structures. These are, in particular, stadiums, sports palaces and water parks, shopping malls, pedestrian, road and railway bridges of various design solutions. The distinctive paper is devoted to theoretical foundations and results of mathematical (numerical) modeling of the state (in terms of the analysis of stress-strain state, strength and stability) of football stadiums built for the 2018 FIFA World Cup in Russia. Finite element method is used for approximation and high-precision numerical solution of corresponding boundary problems of structural mechanics. It is the most universal and powerful numerical method of mechanics. The paper, in particular, describes some features of development of finite element models and the main results of the analysis of the mechanical (structural) safety of three- dimensionallarge-span systems "soil foundation - reinforced concrete structures of foundations and stands - steel structures of the coating and facades" of these football stadiums with the basic and specialload combinations. In addition, the key procedures of scientific support during the corresponding expertise and assessments are outlined. Generally, socially significant and knowledge-intensive problem of providing mechanical (constructive) safety of unique combined objects of construction (three-dimensional systems "foundation - reinforced concrete structures of foundations and stands - steel structures of coating and facades") has been solved at a new level as a result of the performed complex of research works.
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Aniskin, Nikolai A., and Alexey M. Shaytanov. "A full-scale study on the thermal emissivity of concrete and application of its findings to verify ANSYS software package." Vestnik MGSU, no. 6 (June 2022): 727–37. http://dx.doi.org/10.22227/1997-0935.2022.6.727-737.
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Introduction. One of the most popular and complex areas in the design of massive concrete structures is the analysis of their thermal behaviour and thermal stress state. Hence, we can identify tasks related to the phased construction of massive concrete structures, such as gravity dams, massive foundations, bridge supports, etc. A large number of factors, influencing the thermal process, varying over time and depending, among other things, on temperature, determine the complexity of such tasks. The main factor, determining the thermal behaviour of mass concrete in the process of construction, is the exothermic heating of concrete, depending on the type and amount of cement used, as well as several process specifications. Today, such problems can be best solved using the numerical finite element method, implemented in numerous software products. One of them is ANSYS software package, which is widely used to analyze constructions and structures in respect of a full range of actual loadings and impacts. This paper presents the results of the field studies conducted to obtain the initial parameters and verify the precision of results obtained using mathematical modeling techniques of the ANSYS software package.
Materials and methods. The authors describe a full-scale experiment that entails the concreting of a concrete testing block. During concrete placing and curing, temperature sensors time tested a temperature change inside the block and in the outside air. Also, studies were conducted using the numerical finite element method employed by the ANSYS software package.
Results. The findings of a full-scale experiment were compared with the thermal behaviour analysis made by the ANSYS software package. The comparison has proven highly precise results. The maximum temperature difference at the selected points of the full-scale and numerical models does not exceed 0.6 %.
Conclusions. The ANSYS software package solves complex tasks with high accuracy; it determines the thermal behaviour of massive concrete structures, taking into account the thermal emissivity during cement hydration.
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Hamidavi, Tofigh, Sepehr Abrishami, Pasquale Ponterosso, David Begg, and Nikos Nanos. "OSD." Construction Innovation 20, no. 2 (March 14, 2020): 149–69. http://dx.doi.org/10.1108/ci-11-2019-0126.
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Purpose The paper aims to leverage the importance of the integrated automatic structural design for tall buildings at the early stage. It proposes to use an automatic prototype to perform the structural design, analysis and optimisation in a building information modelling (BIM)-based platform. This process starts with extracting the required information from the architectural model in Revit Autodesk, such as boundary conditions and designs different options of the structural models in Robot Autodesk. In this process, Dynamo for Revit is used to define the mathematical functions to use different variables and generate various structural models. The paper aims to expand the domain of automation in the BIM platform to reduce the iterative process in different areas such as conceptual structural design and collaboration between architects and structural engineers to reduce the time and cost at the early stages. Design/methodology/approach The paper begins with an exploratory research by adopting a qualitative methodology and using open-ended questions to achieve more information about the phenomenon of automation and interoperability between structural engineers and architects and gain new insight into this area. Furthermore, correlation research is used by adopting quantitative and short questions to compare the proposed prototype with the traditional process of the structural design and optimisation and the interoperability between architects and engineers and consequently, validate the research. Findings As an outcome of the research, a structural design optimisation (SDO) prototype was developed to semi-automate the structural design process of tall buildings at the early stages. Moreover, the proposed prototype can be used during the early stage of structural design in different areas such as residential buildings, bridges, truss, reinforced concrete detailing, etc. Moreover, comprehensive literature regarding using automation in structural design, optimisation process and interoperability between architects and engineers is conducted that provides a new insight to contribute to future research and development. Research limitations/implications Due to the time limit, the paper results may lack in a comprehensive automatic structural design process. Therefore, the researchers are encouraged to expand the workability of the prototype for a comprehensive automatic design check such as automatic design for the minimum deflection, displacement of different types of buildings. Practical implications The prototype includes implications for the development of different automatic designs. Originality/value The focus of this paper is the optimisation of the structural design in the BIM platform by using automation. This combination is one of the novelties of this paper, and the existing literature has a very limited amount of information and similar work in this area, especially interoperability between architects and engineers.
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Navarro, Miguel Gómez, and Jean-Paul Lebet. "Concrete Cracking in Composite Bridges: Tests, Models and Design Proposals." Structural Engineering International 11, no. 3 (August 2001): 184–90. http://dx.doi.org/10.2749/101686601780346922.
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Kovačević, Miljan, Nenad Ivanišević, Dragan Stević, Ljiljana Milić Marković, Borko Bulajić, Ljubo Marković, and Nikola Gvozdović. "Decision-Support System for Estimating Resource Consumption in Bridge Construction Based on Machine Learning." Axioms 12, no. 1 (December 24, 2022): 19. http://dx.doi.org/10.3390/axioms12010019.
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The paper presents and analyzes the state-of-the-art machine learning techniques that can be applied as a decision-support system in the estimation of resource consumption in the construction of reinforced concrete and prestressed concrete road bridges. The formed database on the consumption of concrete in the construction of bridges, along with their project characteristics, was the basis for the formation of the assessment model. The models were built using information from 181 reinforced concrete bridges in the eastern and southern branches of Corridor X in Serbia, with a value of more than 100 million euros. The application of artificial neural network models (ANNs), models based on regression trees (RTs), models based on support vector machines (SVM), and Gaussian processes regression (GPR) were analyzed. The accuracy of each model is determined by multi-criterion evaluation against four accuracy criteria root mean square error (RMSE), mean absolute error (MAE), Pearson’s linear correlation coefficient (R), and mean absolute percentage error (MAPE). According to all established criteria, the model based on GPR demonstrated the greatest accuracy in calculating the concrete consumption of bridges. According to the study, using automatic relevance determination (ARD) covariance functions results in the most accurate and optimal models and also makes it possible to see how important each input variable is to the model’s accuracy.
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Zeng, Qing Xiang, and Da Jian Han. "Selection of Concrete Creep Analytical Models for Modern Prestressed Bridges." Applied Mechanics and Materials 90-93 (September 2011): 1023–26. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.1023.
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The modern prestressed concrete bridges have the characteristics of large-span, high concrete strength, reinforced volume prestress and linear shape complexity. The structure bearing capacity and durability are considerable impacted by concrete creep, such as stresses redistribution and deflections increase. Some of the prediction concrete creep models that are being widely used at present are briefly introduced in this paper. Based on the analysis of existing research achievement, for the aim of improving the calculation accuracy of creep effects in bridge structures, several main problems that should be paid attention to in concrete creep analysis are pointed out from four aspects: (1) in design stage, the reasonable creep prediction model should be selected in accord with the local building materials and environment conditions; (2) during the analysis of creep effects, the initial stresses state and the stresses redistribution should be attended; (3) the reliability of prestress loss calculation should be considered in analysis of concrete creep effects; (4) the differences between normal construction materials and that of new types should be taken into account in concrete creep analysis.
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Huang, Dongzhou, and Mohsen Shahawy. "Analysis of Tensile Stresses in Transfer Zone of Prestressed Concrete U-Beams." Transportation Research Record: Journal of the Transportation Research Board 1928, no. 1 (January 2005): 134–41. http://dx.doi.org/10.1177/0361198105192800115.
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Prestressed U-beam bridges compare favorably in cost and appearance to traditional concrete I-beam bridges. Consequently, U-beam bridges are gaining in popularity and usage, especially when aesthetic issues are deemed important. U-beam bridges first appeared in Florida in 2000; however, during construction, cracks developed in the webs of the U-beams. This paper presents results of an analysis of representative cracking of U-beams and proposes a practical method for the transfer zone stirrup design. For the purpose of the analysis, the U-beam is divided into a series of finite shell-plate elements, and the prestressing tendons are simulated as a number of concentrated forces. Two different mechanical models of the U-beams are developed on the basis of the stages of construction. Analytical results show that high tensile stresses occur in the end zone of the U-beam because of the prestressing tendons and that these tensile stress must be properly considered in bridge design. The research results are applicable to the design of prestressed U-beams and similar types of prestressed girders.
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Ellobody, Ehab. "Finite element modelling and design of composite bridges with profiled steel sheeting." Advances in Structural Engineering 20, no. 9 (December 1, 2016): 1406–30. http://dx.doi.org/10.1177/1369433216678865.
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This article discusses the non-linear analysis and design of highway composite bridges with profiled steel sheeting. A three-dimensional finite element model has been developed for the composite bridges, which accounted for the bridge geometries, material non-linearities of the bridge components, bridge boundary conditions, shear connection, interactions among bridge components and bridge bracing systems. The simply supported composite bridge has a span of 48 m, a width of 13 m and a depth of 2.3 m. The bridge components were designed following the European code for steel–concrete composite bridges. The live load acting on the bridge was load model 1, which represents the static and dynamic effects of vertical loading due to normal road traffic as specified in the European code. The finite element model of the composite bridge was developed depending on additional finite element models, developed by the author, and validated against tests reported in the literature on full-scale composite bridges and composite bridge components. The tests had different geometries, different boundary conditions, different loading conditions and different failure modes. Failure loads, load–mid-span deflection relationships, load–end slip relationships, failure modes, stress contours of the composite bridge as well as of the modelled tests were predicted from the finite element analysis and compared well against test results. The comparison with test results has shown that the finite element models can be effectively used to provide more accurate analyses and better understanding for the behaviour and design of composite bridges with profiled steel sheeting. A parametric study was conducted on the composite bridge highlighting the effects of the change in structural steel strength and concrete strength on the behaviour and design of the composite bridge. This study has shown that the design rules specified in the European code are accurate and conservative for the design of highway steel–concrete composite bridges.
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Kubota, Satoshi, and Ichizou Mikami. "Development of Product Data Model for Maintenance in Concrete Highway Bridges." Applied Computational Intelligence and Soft Computing 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/148785.
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The primary objective of this paper is to develop the product data models, in which systematic information is defined for accumulating, exchanging, and sharing in the maintenance of concrete highway bridges. The information requirement and existing issues and solutions were analyzed based on the life cycle and the standardization for sharing. The member data models and business data models that defined design and construction information and accumulated results information were developed. The maintenance business process in which project participants utilize the product data model was described as utilization scenario. The utilization frameworks which define information flow were developed.
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Marian, Stănescu Răzvan. "Steel and Concrete Elasto-Plastic Models at Bridges with Steel Beams Embedded in Concrete." Romanian Journal of Transport Infrastructure 7, no. 1 (July 1, 2018): 64–76. http://dx.doi.org/10.2478/rjti-2018-0004.
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Abstract For new railway bridges with short spans (L ≤ 35.00 m) superstructures with steel beams embedded in concrete are recommended or used, which can ensure the requirements of strength and stiffness in particular, regardless of velocity. They are built relatively easily compared to reinforced concrete structures or steel structures, they have high durability if designed, built and maintained correctly and don’t have high sensitivity to fatigue degradation in service. They are also used for road bridges when it is desired to achieve a reduced construction height. In all the design prescriptions used so far for structures with steel beams embedded in concrete, the calculation is a simplified one, made on a single insulated longitudinal beam of the deck, if certain conditions related to the geometry of the structure are met (obliquity, curvature). Simplifications are also made regarding the state of deformation of the decks made in this constructive solution by introducing an effective moment of inertia in the displacement calculation, as an average of the inertia moments of the cross section considered to be cracked and respectively un-cracked. The article aims to validate steel and concrete elasto-plastic models, based on an experiment from the technical literature, necessary for complex analyses of the percentage of concrete involved in the stiffness of the cross-sections, in case of bridges with steel beams embedded in concrete.
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Fragkakis, Nikolaos, Sergios Lambropoulos, and John-Paris Pantouvakis. "A Computer-Aided Conceptual Cost Estimating System for Pre-Stressed Concrete Road Bridges." International Journal of Information Technology Project Management 5, no. 1 (January 2014): 1–13. http://dx.doi.org/10.4018/ijitpm.2014010101.
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The need for an environmentally friendly design of modern motorways increases the construction of bridges, which has exhibited substantial overruns above estimated costs. Therefore, easy to use, inexpensive and accurate methods for conceptual cost estimating are needed. This paper presents a computer-aided cost estimating system for pre-stressed concrete road bridges that provides estimates of the material quantities and cost of all bridge elements. It relies on a database incorporating actual data collected from recently constructed bridges and exploits material estimating models developed with statistical analysis. Different configurations are devised from short to long-span bridges, accounting for the major deck construction methods and foundation systems. The system can be easily used to provide different cost estimates to the owner, designer and contractor during the project's early stages. By allowing reliable cost estimates in a short time, the proposed computer-aided system represents a useful decision making tool.
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Kvocak, Vincent, Daniel Dubecky, and Viktoria Kozlejova. "Experimental Verification of Design Models in a Static and Dynamic Loading Test." Key Engineering Materials 763 (February 2018): 394–99. http://dx.doi.org/10.4028/www.scientific.net/kem.763.394.
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Nowadays more and more often investors and constructors are building constructions by combining two of the most common materials: reinforced concrete and steel. By understanding their behavior we can squeeze a mountain of used material with better results. They make it possible to take advantage of good mechanical properties of concrete in compression and steel in tension. One of the commonest types of composite structures is deck bridges with encased filler beams. These types of construction have been employed in Slovakia and all over Europe without any major change since the beginning of the 19th century. Several steel sections of modified shapes and dimensions were designed and tested in the Laboratories of the Institute of Structural Engineering at the Technical University in Košice. The main goal was to design and experiment with deck bridges made of various sections so as to maximise their cost-effectiveness by reducing the amount of steel consumed. Based on theoretical analyses, specimens were prepared in the laboratory, consisting of a variety of fully encased steel sections. It was cast into the prepared steel formwork placed on a fixed bearing plate so as to prevent deflection of composite beams during the concreting process.
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Laco, Kamil, and Viktor Borzovič. "Design of Approach Slab of Road Bridges." Solid State Phenomena 249 (April 2016): 215–20. http://dx.doi.org/10.4028/www.scientific.net/ssp.249.215.
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This paper deals with the design and assessment of approach slabs of the transition zones of road bridges. The main goal of this article is to evaluate design criteria of this reinforced concrete member with attention to the requirements according to European standards. Up to these days, used procedure for the design of the approach slabs of the bridge construction in Slovakia is based on previous Czechoslovak CSN 73 6244 standard introduced 1981. The reason for using this standard nowadays is mainly because of its simple form as an engineering tool for the design of the geometrical dimension and also the reinforcement of the approach slab. Design procedures used for the analysis are taking into account the simplest and also the most conservative structural schemes, it is the slab with a hinge support in the place of the abutment and the second simple support on the other side substituting the gravel subsoil. This scheme should represent possible consolidation of the embankment under the slab. For more precise description of the behaviour, models with elastic support are used. Using these models, the approach slabs will be analysed for the ultimate limit state. The analysis of the results for various geometrical dimensions could serve as a template for similar design tool, to which bridge designers are used to.
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Giordano, Aldo, Ionuţ Radu Răcănel, and Giovanni Voiro. "Steel-Concrete Viaducts in the Orastie-Sibiu Highway: a Eurocode Compliant Project." Romanian Journal of Transport Infrastructure 2, no. 1 (July 1, 2013): 51–62. http://dx.doi.org/10.1515/rjti-2015-0011.
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Abstract This paper is intended to show the design of two composite bridges along the Orastie- Sibiu motorway, from the basic concepts, applied without the need for a clause-by- clause checking of codes and standards, to the construction methods. The bridges are seismically isolated in the longitudinal direction, while transversally the seismic action is distributed among the piers. Calculations have been carried out through state of the art procedures, taking into account form effect of the cross section. For this reason, different FE models have been set up to study different aspects of the behavior, with increasing degrees of approximation. For example, “beam” elements have been utilised to investigate global effects both in the linear and non linear range, while more accuate 2D and 3D elements have been used for refined cases such as stress checks and local buckling analyses. The present paper goes into detail in particular for what concerns some of the most interesting parts of the design process for the specific case. Namely, time dependent properties of the materials have been considered, and extensive “staged construction” analyses have been carried out to ensure safety in each phase of the complex life of the bridges, while at the same time guaranteeing significant cost savings.
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Kim, Sang-Hyo, Tuguldur Boldoo, Dae-Yoon Kim, Inyeop Chu, and Sang-Kyun Woo. "Probabilistic Moment Capacity Models of Reinforced Concrete Slab Members for Underground Box Culverts." Applied Sciences 11, no. 18 (September 14, 2021): 8520. http://dx.doi.org/10.3390/app11188520.
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This study was performed to evaluate the probabilistic characteristics of the flexural strength of reinforced concrete (RC) flexural members adopted for underground box culverts. These probabilistic models were developed to be adopted for the development of limit state load combination formats for underground RC box culverts. The probabilistic models of uncertainties inherent in the basic design variables were developed to evaluate flexural strength using field material test data as well as field survey data collected from various domestic construction sites of underground box culverts in Korea. The basic design variables include concrete strength, steel rebar strength, and section dimensions, such as slab thickness and rebar locations. Some design variables are assumed to have inherent construction error characteristics, which may be different from those inherent in the RC members for buildings and bridges. The bias models on flexural strength were evaluated based on the experimental results of four-point flexural tests on one-way RC slabs, which were fabricated following the general practice adopted in the local underground box culvert construction process. Based on the probabilistic models of basic design variables, as well as the bias models of flexural strength, Monte Carlo simulations were performed to examine the probabilistic characteristics of both ultimate flexural strength and yield moment strength of RC slab members. Some sensitivity analyses were performed to confirm the soundness of various probability models and the assumptions adopted in the development procedure. The proposed procedure may be applied to develop probabilistic resistance models for structural members, in which the construction error characteristics are assumed to be different from other practices.
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Yashnov, Andrey, and Pavel Kuzmenkov. "Innovative aspects in developing bridge monitoring systems." MATEC Web of Conferences 216 (2018): 01009. http://dx.doi.org/10.1051/matecconf/201821601009.
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The average age of bridges in operation and their accumulated damage are ever increasing, while design solutions of new bridges are increasingly complex. It is difficult to adequately reflect performance characteristics of these structures in design models. In order to prevent accidents during construction and operation, it is necessary to verify experimentally that the actual stress-strain behavior corresponds to design parameters. Special monitoring systems are developed and implemented to improve the operational reliability of structures. This study uses mathematical modeling and instrumental measurements to develop monitoring systems. A systematic approach has been implemented. The paper presents the results produced by modern automated measuring, recording and data processing equipment to provide online diagnostics and long-term status monitoring of bridge structures.
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Cheung, M. S., and S. H. C. Foo. "Design of horizontally curved composite box-girder bridges: a simplified approach." Canadian Journal of Civil Engineering 22, no. 1 (February 1, 1995): 93–105. http://dx.doi.org/10.1139/l95-009.
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Because of their excellent torsional capacity, box girders are used extensively in modern bridge construction having curved alignments. Applications of most design codes have been limited to bridges where the radius of curvature is much greater than the span length and cross-sectional dimensions. To meet the practical requirements arising during the design process, simple design methods are needed for curved bridges. This paper presents the results of a parametric study on the relative behaviour of curved and straight box-girder bridges and on the development of a simplified design method for the combined longitudinal moment of curved bridges. The combined moment includes the effects of flexure, torsion, and distortion. Three simply supported concrete-steel composite bridge models, including single-cell, twin-cell, and three-cell box girders and subjected to loadings as specified in the Ontario Highway Bridge Design Code, were analyzed using the finite strip method. The parameters considered in the study include types of cross section; types, locations, and magnitudes of loads; span lengths; and radius of curvature. Preliminary analysis of the results suggests that the behaviour of horizontally curved box-girder bridges is dependent on a variety of parameters, but most importantly on the span-to-radius ratio. Empirical relationships for combined longitudinal moment between curved and straight box-girder bridges are also proposed. Key words: bridge, curved, composite, design, finite strip.
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Márquez-Peñaranda, J. F., J. R. Pineda-Rodríguez, and J. P. Rojas-Suárez. "An application of physics: simply supported bridges made of post-tensioned concrete and structural steel beams." Journal of Physics: Conference Series 2153, no. 1 (January 1, 2022): 012004. http://dx.doi.org/10.1088/1742-6596/2153/1/012004.
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Abstract Bridges represent an important application of physics capable of solving real transportation problems. Knowledge of convenience of different mechanical solutions when analyzing and designing bridge is needed. For these reasons, this work is focused on the study of convenience of using two types of bridges. Simply supported short-medium span bridges (30 m to 45 m) are usually excessively long when choosing reinforced concrete solutions and usually short for other types of structures such as cable-stayed or cantilever bridges. The suitability of simply supported bridges leads to the need of studying their cost benefit ratios. This work studies the cost benefit ratio for post-tensioned concrete beams and structural steel girders in simply supported straight bridges. Eight models built of type I sections were used in both cases to analyze the bridges using a software based on the stiffness method. Span of each bridge was set to 30 m, 35 m, 40 m, and 45 m. The convenience of each type of bridge was done comparing the total and the cost per linear meter of each solution (post-tensioned and structural steel). Comparison was done using material consumption, labor, and construction processes costs only. Also, allowable vertical displacement given by current bridge design standards was verified.
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Kondapally, Pavitra, Akhilesh Chepuri, Venkata Prasad Elluri, and B. Siva Konda Reddy. "Optimization of concrete mix design using genetic algorithms." IOP Conference Series: Earth and Environmental Science 1086, no. 1 (September 1, 2022): 012061. http://dx.doi.org/10.1088/1755-1315/1086/1/012061.
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Abstract Most of the engineering construction projects of bridges, dams consume huge quantities of concrete and other materials. Economical design can be better achieved by optimising the quantities of materials without affecting functionalities of structures. Minimising the proportions or quantities of materials without affecting its functional characteristics in a concrete mix results in most cost efficient design process. This study presents the technique of optimisation of concrete mix design applying Genetic Algorithms using a developed MATLAB program. Concrete mix design was performed for different grades of concrete and water cement ratio. It is observed that the use of Genetic Algorithms resulted in economical mix by minimizing the cement content keeping the strength of concrete unaffected. The study results indicated that quantities of cement have been reduced by about 25-40 kg per cubic meter through mix design using GA technique. This resulted in about 6-10 percent reduction in quantities of cement for various cases of mix design considered in the study. Mix design performed using optimization techniques like GA proved to be efficient when compared to mix design using manual approach. Further, the models for predicting compressive strength under different proportions of materials can also be analyzed using GA approach presented in this study.
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Ashiquzzaman, Md, Li Hui, Ahmed Ibrahim, Will Lindquist, Nader Panahshahi, and Riyadh Hindi. "Exterior girder rotation of skew and non-skew bridges during construction." Advances in Structural Engineering 24, no. 1 (July 30, 2020): 134–46. http://dx.doi.org/10.1177/1369433220945061.
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In bridge design, bridge decks regularly overhang past the exterior girders in arrange to extend the width of the deck whereas constraining the specified number of girders. The overhanging part of the deck comes about in uneven eccentric loads to the exterior girders which are by and large most prominent. These eccentric loads are primarily a result of bridge construction operations as well as the weight of new concrete and other construction live loads. These unbalanced loads can lead to a differential edge deflection of overhang deck and a rotation of the exterior girders. The girder rotation or differential deck deflection can also affect local and global stability of the entire bridge. The objective of this study is to enhance the knowledge and understanding of external girder behavior due to unbalanced eccentric construction loads and to identify the critical factors affecting their rotation. In this article, field data obtained during the construction of two skewed (one with a small skew (3.8°) and the second with a severe skew (24°)) and one non-skewed steel girder bridges are described, and a detailed comparison is presented. The three bridges experienced maximum outward exterior girder rotation during construction which subsequently decreased following construction operations. The field results were used to validate and calibrate the finite element models. The numerical and field-monitored data showed good agreement and can be used to assist bridge designers and construction engineers to design appropriate systems to limit girder rotation during construction.
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Asnina, Erika, and Begoña Cristina Pelayo García-Bustelo. "The Perspective on Data and Control Flow Analysis in Topological Functioning Models by Petri Nets." Applied Computer Systems 16, no. 1 (December 1, 2014): 77–84. http://dx.doi.org/10.1515/acss-2014-0016.
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Abstract The perspective on integration of two mathematical formalisms, i.e., Colored Petri Nets (CPNs) and Topological Functioning Model (TFM), is discussed in the paper. The roots of CPNs are in modeling system functionality. The TFM joins principles of system theory and algebraic topology, and formally bridges the solution domain with the problem domain. It is a base for further automated construction of software design models. The paper discusses a perspective on check of control and data flows in the TFM by CPNs formalism. The research result is definition of mappings from TFMs to CPNs.
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Gopal, Balamurugan A., Farzad Hejazi, Milad Hafezolghorani, and Voo Yen Lei. "Numerical analysis and experimental testing of ultra-high performance fibre reinforced concrete keyed dry and epoxy joints in precast segmental bridge girders." International Journal of Advanced Structural Engineering 11, no. 4 (October 23, 2019): 463–72. http://dx.doi.org/10.1007/s40091-019-00246-6.
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Abstract Although ultra-high performance fiber reinforced concrete (UHPFRC) has been used recently as a sustainable construction technique for many precast segmental bridges (PSBs), no exhaustive numerical and experimental studies exist to assess the shear capacity and failure pattern of the joints in these bridges. Hence, to accurately investigate the shear behavior of the joints in UHPFRC precast segmental bridges, a numerical analysis model based on finite-element code was established in this study. Concrete damaged plasticity model was used to analyze the UHPFRC joint models by considering all the geometries, boundaries, interactions and constraints. In this paper, the numerical model was calibrated by two full-scale UHPFRC keyed dry and epoxy joints under confining pressure effect. The excellent agreement between the numerical results and experimental data demonstrated the reliability of the proposed numerical model. The validated numerical model was then utilized to investigate the parameters affecting shear behaviour of the joints in PSBs. For this purpose, 12 FE models were analyzed under different variable parameters namely, number of shear keys, confining stress, and types of joints (dry or epoxy). Furthermore, the numerical results were also compared with the five existing shear design provision models available in literature in terms of ultimate shear capacity.
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Sundar, N., PN Raghunath, and G. Dhinakaran. "Flower pollination-based optimal design of reinforced concrete beams with externally bonded of FRPS." Advanced Composites Letters 29 (January 1, 2020): 2633366X2096249. http://dx.doi.org/10.1177/2633366x20962499.
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The optimal design of reinforced concrete beams (RCBs) and structures with an objective of improving the chosen performances is an important problem in the field of construction works. Recently, the concrete beams, structures, and walls are strengthened externally by bonding fiber-reinforced polymer strips (FRPS). Usually, FRPS are employed in rehabilitation of existing beams, bridges, and other structural elements. This article modifies the problem of designing new RCBs with appropriate selection of FRPS with a goal of exploiting the benefits of FRPS such as higher tensile strength, better corrosion resistance, higher stiffness-to-weight ratio, and longer life. It, firstly, proposes an artificial neural network-based mathematical model for assessing the performances of RCBs bonded with FRPS from the data obtained from 69 FRPS-glued RCBs and then develops an optimal design procedure employing flower pollination-based optimization, which is imitated from the pollination process of plants, for obtaining design parameters of FRPS-glued RCBs with a view of enhancing both the ultimate load and the deflection ductility. It presents optimal design parameters of five FRPS-glued RCBs and experimentally validates the performances.
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Sun, Yuan, Shucai Dai, Dong Xu, Hongping Zhu, and Xiaoming Wang. "New extended grillage methods for the practical and precise modeling of concrete box-girder bridges." Advances in Structural Engineering 23, no. 6 (December 6, 2019): 1179–94. http://dx.doi.org/10.1177/1369433219891559.
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The Hambly plane grillage method has been regarded as one of the classic numerical methods in the design field for modeling wide box-girder bridge structures. However, when it comes to the in-depth design applications, its strict division rules and insufficient mechanical explanations often make engineers inconvenient or puzzled at bridge modeling. This article investigates whether this method may be extended to become more adaptable for the design of current concrete box-girder bridge structures in consideration of both convenience and precision. To this end, the defects of Hambly plane grillage method are recognized, and new extended grillage methods, including the single-layer folding surface grillage and spatial grillage, are proposed respectively, to deal with different bridge design objects completely in a beam-oriented environment. The former allows freer cross-sectional division by breaking the basic rule of Hambly plane grillage method to include longitudinal separate-type beam components for a better exhibition of shear lag effects. The latter emphasizes a complete consideration of spatial behavior, including the easily missed in-plane effects of the top and bottom plates. The effectiveness of the methods are demonstrated by comparison case studies in some benchmark models and by a discussion of their applications.
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Naser, Ali Fadhil, Hussam Ali Mohammed, and Ayad Ali Mohammed. "Mathematical Modeling of Linear Static and Dynamic Analysis for Pier Height Effect on the Structural Performance of Bridges Structures." Mathematical Modelling of Engineering Problems 8, no. 4 (August 31, 2021): 617–25. http://dx.doi.org/10.18280/mmep.080415.
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The results of linear static analysis explained that the increasing of pier heights was leaded to rise the values of positive bending moment, tensile stresses, and downward vertical deflection. Whereas the compressive stresses and negative bending moment were decreased, indicating that the structural performance of bridge structure representing by stiffness, bearing capacity of structural members, and elasticity will decrease and the bridges structures will be damaged. Therefore, the bridges structures need safe design when using tall piers by adopting high quality materials such as high strength concrete, more steel reinforcement, more prestressed tendons, and increasing of cross section dimensions of girders and piers. The results of modal analysis show that the un-loaded dynamic frequency for three types of bridges models were decreased when the pier heights were increased, indicating that the stiffness of bridges structure was became low with higher pier height. According to response spectra and time history analysis results, the loaded dynamic frequency (vibration state) and dynamic displacement were increased when the pier heights were increased, showing that the bridge of structure will suffer from high vibration when the pier height was high. It can be concluded that from this study, the piers heights have significant effects on the static and dynamic structural performance of bridges structures under traffic loads.
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Kolínský, Vojtěch, and Jan L. Vítek. "Analysis of Long-Term Observation of Highway Arch Bridge Oparno." Solid State Phenomena 249 (April 2016): 209–14. http://dx.doi.org/10.4028/www.scientific.net/ssp.249.209.
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The paper deals with evaluation of experimental data collected during the Oparno arch bridge construction and with subsequent analysis of the construction process and long-term behavior with regard to rheological properties of concrete. The Oparno valley bridge is composed of two separate concrete arch structures with spans of 135 metres (this is currently the second longest span of concrete arch bridge in the Czech Republic). It was built using cantilever casting technology with temporary cable-stays and auxiliary pylons. The data recorded for this study include detailed geodetic measurement of the bridge structure during construction, along with measured strains and temperatures in the arches. Most of the data was measured during the bridge construction in 2008 and 2009. Data significant for long term behavior of structure are still being collected. Verification of different concrete material models and their suitability for design of arch bridges built by free cantilevering will be a main result of the analysis. On the basis of a detailed comparison of numerical results and measured deflections, strains and temperatures, it is possible to quantify the impact of rheological properties of the material (or their individual input parameters) on the resulting structural behavior. Unlike previous research, the examined structure is made of reinforced concrete (not prestressed) and consists of compact solid section and in the final state it is mainly in compression.
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Vojtasik, Karel, Eva Hrubesova, Marek Mohyla, and Lukáš Duris. "Design and Evaluation of a Subterranean Work Lining from Layers of Shotcrete and Steel Arch." Advanced Materials Research 1020 (October 2014): 347–50. http://dx.doi.org/10.4028/www.scientific.net/amr.1020.347.
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A steel concrete lining is today the common ground massive retaining structure implemented shortly after the excavation of an opening. The constituent elements of the steel concrete lining are layers of shotcrete and steel arch frames. This simple structure has many unique features which set it apart from the conventional reinforced concrete constructions. Without simplification these features doesn’t allow to carry out design and evaluation of steel concrete lining by relevant design and evaluation methods convenient to the conventional reinforced concrete constructions. The main differences are construction process, yielding curve of structure and determination of external load. In the case of a steel concrete lining its external load is product of mutual work of both the ground massive and the lining. The value of load depends on the yielding curves of the lining and the ground massive. The yielding curve of a ground massive is objective and conditioned on strength strain properties of ground massive and primary stress state. The yielding curve of a steel concrete lining relates lining design specification. The process of construction affects the value of load too. The article analyzes the steel concrete lining focusing the influence of lining design parameters on its yielding curve. It looks for a way to control the ground massive behavior and as well as to engage it more in an effort with lining to stabilize subterranean work. The themes of the analysis are: static and deformation parameters of the cross-section of the steel concrete lining with regard to the construction stage and dependency of hardening shotcrete; interaction between of steel concrete lining and ground massive based on yielding curves; assessment of a stress state across the steel concrete lining section in the steel concrete lining constituent elements. The analysis is carried out on mathematical models that combine analytical and numerical methods.
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Jones, Jared, Elmira Shoushtari, M. “Saiid” Saiidi, and Ahmad Itani. "Comparison of Seismic Performance of Socket and Pocket Connections for Reinforced Concrete Bridge Column Base Hinges." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 5 (April 16, 2020): 349–60. http://dx.doi.org/10.1177/0361198120915695.
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The goal of this study was to evaluate two connection types for reinforced concrete two-way rebar hinges and to assess their seismic performance if incorporated in accelerated bridge construction applications. Two large-scale models of bridge systems were tested on shake tables; the first utilized a pocket connection with the opening preformed in the column and the second implemented a socket connection with the opening preformed in the footing. Both bridges were subjected to multiple ground motions ranging from 30% to 225% of the design level earthquake. Rebar hinge behavior during the earthquakes including interface slippage, rotation, reinforcement strains, observed damage, and bent forces were used to evaluate the connections and their relative merit and to make recommendation for implementation in the field.
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Lisienkova, Liubov, Tatiana Shindina, Nina Orlova, and Liudmila Komarova. "Optimization of the Concrete Composition Mix at the Design Stage." Civil Engineering Journal 7, no. 8 (August 1, 2021): 1389–405. http://dx.doi.org/10.28991/cej-2021-03091732.
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The problem of the composition optimization of concrete mixes seems to be quite urgent as errors at the composition design stage can lead to problems of concrete at the stage of exploitation such as delamination, cracking etc. Reasonable selection of concrete mix components guarantees the required strength of concrete and reinforced concrete structures in the future. This paper investigates the influence of the concrete mix composition on the strength of concrete. Firstly, typical risks that can occur on the composition design stage have been identified through the experts' interviews. Secondly, this risks were associated with indicators and characteristics that can be tested experimentally. Running of several mathematical models has allowed to outline concrete mix parameters of highest importance and formulate an empirical equation for the dependence of the strength of the concrete mixture on the values of the coarse aggregate quality factor, the fine aggregate fraction and the consumption of the Portland cement has been proposed. As a result, a methodology for controlling the quality of concrete at the stage of the composition design has been formulated. Doi: 10.28991/cej-2021-03091732 Full Text: PDF
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Rahman, Muhammad Ekhlasur, Timothy Zhi Hong Ting, Hieng Ho Lau, Brabha Nagaratnam, and Keerthan Poologanathan. "Behaviour of Lightweight Concrete Wall Panel under Axial Loading: Experimental and Numerical Investigation toward Sustainability in Construction Industry." Buildings 11, no. 12 (December 6, 2021): 620. http://dx.doi.org/10.3390/buildings11120620.
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Awareness of sustainability in construction has led to the utilization of waste material such as oil palm shell (OPS) in concrete production. The feasibility of OPS as alternative aggregates in concrete has been widely studied at the material level. Meanwhile, nonlinear concrete material properties are not taken into account in the conventional concrete wall design equations, resulting in underestimation of lightweight concrete’s wall axial capacity. Against these sustainability and technical contexts, this research investigated the buckling behavior of OPS-based lightweight self-compacting concrete (LWSCC) wall. Failure mode, load-deflection responses, and ultimate strength were assessed experimentally. Numerical models have been developed and validated against experimental results. Parametric studies were conducted to study the influence of parameters like slenderness ratio, eccentricity, compressive strength, and elastic modulus. The results showed that the axial strength of concrete wall was very much dependent on these parameters. A generalized semi-empirical design equation, based on equivalent concrete stress block and modified by mathematical regression, has been proposed. The ratio of average calculated results to test results of the proposed equation, when compared to ACI 318, AS 3600, and Eurocode 2 equations, are respectively improved from 0.36, 0.31, and 0.42 to 0.97. This research demonstrates that OPS-based LWSCC concrete can be used for structural axial components and that the equation developed can serve a good guideline for its design, which could encourage automation and promote sustainability in the construction industry.
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Murashkin, Vasily G. "Features of Nonlinear Deformation of Concrete." Scientific journal “ACADEMIA. ARCHITECTURE AND CONSTRUCTION”, no. 1 (March 18, 2019): 128–32. http://dx.doi.org/10.22337/2077-9038-2019-1-128-132.
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In most studies, when the problem of determining a nonlinear model of deformation of structural concrete in normal environment, or experienced a variety of destructive (aggressive, temperature, etc.) exposure, using individual mathematical apparatus and software. The main criterion in these works for the construction of the deformation model of concrete was a unique relationship "strength - modulus of elasticity". Apply the developed model for another type of concrete or experienced a destructive impact was erroneous. However, not all features of concrete deformation in the construction of models were taken into account. In particular, the gentle nature of deformation in the initial stage of loading was not taken into account. Similarly, models of nonlinear deformation of concrete in normative materials of different countries are constructed. Especially there are problems in the inspection of structures operated for along time. It is not rational to create individual models based on the algorithm created earlier. In recent studies, a number of works have noted the need to take into account the features of the initial stage ofloading of concrete and the fact that concrete from the beginning ofloading has macro and micro cracks and structural defects. But even in these works the possibility of creating a nonlinear deformation model based on experimentally obtained data when testing prototypes of generalized model was not considered. This article discusses the possibility of constructing a concrete extracted from the structure. The possibility of replacing the individual deformation models with the proposed one is shown. In the generalized model of deformation "strength and modulus of elasticity" may not coincide with the normative characteristics and it can serve as a basis for determining the stress state in the survey of operated structures and, if necessary, for the design of new ones.
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Fang, Yao-Min, and Jun-Ping Pu. "Field Tests and Simulation of Lion-Head River Bridge." Shock and Vibration 14, no. 3 (2007): 181–228. http://dx.doi.org/10.1155/2007/348640.
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Lion-Head River Bridge is a twin bridge in parallel position. The east-bounded was designed and constructed as a traditional prestress concrete box girder bridge with pot bearings; and the west-bounded was installed with seismic isolation devices of lead rubber bearings. The behavior of the isolated bridge is compared with that of the traditional bridge through several field tests including the ambient vibration test, the force vibration test induced by shakers, the free vibration test induced by a push and fast release system, and the truck test. The bridges suffered from various extents of damage due to the Chi-Chi and the Chi-I earthquakes of great strength during the construction and had been retrofitted. The damage was reflected by the change of the bridges' natural frequencies obtained from the ambient vibration tests. The models of the two bridges are simulated by the finite element method based on the original design drawings. Soil-structure interaction was also scrutinized in this study. The simulation was then modified based on the results from the field tests. Dynamic parameters of bridges are identified and compared with those from theoretical simulation. The efficiency is also verified to be better for an isolated bridge.
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Mante, David M., Robert W. Barnes, Levent Isbiliroglu, Andric Hofrichter, and Anton K. Schindler. "Effective Strategies for Improving Camber Predictions in Precast, Prestressed Concrete Bridge Girders." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 3 (March 2019): 342–54. http://dx.doi.org/10.1177/0361198119833965.
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In order to limit construction conflicts in bridges with precast, prestressed concrete girders, it is essential that designers are able to predict midspan girder camber with sufficient accuracy at key stages. This paper describes a study of the effectiveness of various strategies for improving camber predictions when compared with field-measured values from actual bridge girders produced in the southeastern United States. The study also incorporated concrete materials data from nearly 2000 girder production cycles among four regional producers, in addition to a laboratory study of mechanical and time-dependent properties of representative concrete mixtures. A standard incremental time-step analysis software was developed and utilized for the parametric study included in this work. For the girder production cycles monitored in this study, the use of regionally calibrated prediction models for material properties (concrete compressive strength, modulus of elasticity, creep, and shrinkage) resulted in the elimination of approximately 80% of the prediction error associated with current camber prediction practices within the region. As compared with a mean overprediction error of 68% for current design practice, implementation of calibrated prediction models reduced the mean overprediction to approximately 10%. The most effective prediction improvement techniques were determined to be reliance on expected rather than specified concrete compressive strength, the use of an appropriate aggregate correction factor for modulus of elasticity computations, and the use of an incremental time-step analysis method incorporating AASHTO Load and Resistance Factor Design (LRFD) or International Federation for Structural Concrete ( fib) Model Code 2010 creep and shrinkage prediction equations.
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Ouahmane, Issam, Rachid El Alaiji, Mohammed Sallaou, and Larbi Lasri. "General Mathematical Model for Analysing the Bending Behaviour of Rectangular Concrete Beams with Steel, Fibre-Reinforced Polymers (FRP) and Hybrid FRP–Steel Reinforcements." Buildings 12, no. 11 (November 12, 2022): 1964. http://dx.doi.org/10.3390/buildings12111964.
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The design guidelines available in building codes for steel and fibre reinforced polymer (FRP) reinforced concrete (RC) beams have been developed on the basis of empirical models. While these models are successfully used for practical purposes, they require continuous improvements with more experimental data. This paper aims to develop a general mathematical model derived from the intrinsic material properties of concrete and certain reinforcements to analyse the bending behaviour of reinforced concrete beams. The proposed model takes into account the effects of non-linearity and ductility on the real behaviour of concrete under compression as well as the concrete tension stiffening. The model focused on analysing the flexural behaviour of rectangular steel, FRP and hybrid FRP–steel RC beams, using the moment–curvature relationship. A general static equilibrium equation was developed and mathematically solved with precise methods to establish a moment–curvature relationship. The effective flexural stiffness (EFS) is therefore calculated by the slope of the moment–curvature diagram, and then the load–deflection response is immediately deduced according to the loading conditions. The present model results were compared with numerous test data reported by various researchers. The comparisons reveal a good accuracy for predicting the EFS and load–deflection response for either steel, FRP, and hybrid reinforced concrete beams, with an error average less than 10%.
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Kabanov, Vadim. "Information model for choosing a design solution for providing construction with mortar." E3S Web of Conferences 281 (2021): 04001. http://dx.doi.org/10.1051/e3sconf/202128104001.
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Building materials are usually classified according to the criterion of the possibility of creating a stock at the construction site. Mortars and concrete mixtures have a limited time during which they must be used in the construction of building structures. There are technologies for the use of dry components of mortars from which the mixture is prepared at the construction site. However, the technology of manufacturing mortars at specialized plants is widely used, followed by transportation of the finished cement-sand mixture to the construction site. The problem under consideration raises issues related to the volume of supply of mortars and the intensity of this building material consumption. Within the framework of the research, the tasks of analytical description of the construction and installation work intensity influence on the technological processes of cement-sand mortars delivery to the construction site have been solved, a block diagram of the selection of an economically feasible design solution for providing the production process with a building mixture has been developed. On the basis of the presented results in the form of mathematical dependencies and a block diagram, the conclusions about the influence of a design solution for providing construction with a cement-sand mixture on the duration and construction and installation work cost have been formulated. A graphic representation of the procedure for making a decision on the supply of a construction with a cement-sand mixture is supposed to be used for the development of software that provides a description of the construction processes functioning in space and time, including for 3D models.
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Yang, Yumin, and John J. Myers. "Live-Load Test Results of Missouri’s First High-Performance Concrete Superstructure Bridge." Transportation Research Record: Journal of the Transportation Research Board 1845, no. 1 (January 2003): 96–103. http://dx.doi.org/10.3141/1845-11.
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For its significant economical savings and greater design flexibility, high-performance concrete (HPC) is becoming more widely used in highway bridge structures. High-performance bridges with HPC and large-diameter prestressed strands are becoming attractive to designers. Bridge A6130 is the first fully HPC superstructure bridge in Missouri. The bridge has HPC cast-in-place deck and high-strength concrete girders reinforced with 15.2-mm (0.6-in.) diameter strands. The bridge was instrumented with embedded strain gauges and thermocouples to monitor the early-age and later-age behavior of the structures from construction through service. To investigate the overall behavior of the bridge under live load, a static live-load test was developed and carried out. During the live-load test, 64 embedded vibrating wire strain gauges and 14 embedded electrical-resistance strain gauges were used to acquire the changing strain rate in the bridge caused by the varying live-load conditions. Girder deflections and rotations were also recorded with external sensors and a data acquisition system. Based on the test results, the load distribution to the girders was studied. The AASHTO specifications live-load distribution factor recommended for design was compared with the measured value and found to be overly conservative. The AASHTO load and resistance factor design live-load distribution factors recommended for design were found to be comparable to measured values. Two finite element models were developed with ANSYS and compared with measured values to investigate the continuity level of the Missouri Department of Transportation interior bent detail.
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Kessal, Oussama, Larbi Belgraa, Noura Djebri, Soumia Salah, and Zineb Allal. "Improvement of the Mechanical Behavior of an Environmental Concrete Based on Demolished Concrete Waste and Silica Fume." Civil Engineering Journal 8, no. 2 (February 1, 2022): 238–50. http://dx.doi.org/10.28991/cej-2022-08-02-04.
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The universal need to conserve resources, protect the environment, and use energy efficiently must necessarily be felt in the field of concrete technology. In Algeria, the rapid growth in the construction sector and the difficulties in setting up new quarries make it necessary to find effective alternatives to use them as building materials. The recycling of construction and demolition waste as a source of aggregates for the production of concrete has attracted growing interest from the construction industry. In this context, this work is a part of the approach to provide answers to concerns about the lack of aggregates for concrete. It also aims to develop the inert fraction of demolition materials, mainly concrete construction demolition waste (C&D), as a source of aggregates for the manufacture of new hydraulic concrete based on recycled aggregates. This experimental study presents the results of physical and mechanical characterizations of natural and recycled aggregates, as well as their influence on the properties of fresh and hardened concrete. The characterization of the materials used has shown that the recycled aggregates have heterogeneity, a high-water absorption capacity, and medium-quality hardness. However, the limits prescribed by the standards in force do not disqualify these materials from use for application as recycled aggregate concrete. The effect of silica fume and superplasticizer percentage on the mechanical and physical properties of concrete with NA and RA was analyzed and optimized using full-factorial design methodology. The results obtained from the present study show acceptable mechanical, compressive, and flexural strengths of concrete based on recycled aggregates by using Superplasticizer and 5% of silica fume, compared to those with natural aggregates. The results of the water absorption as well as the UPV confirm the positive effect of the use of superplasticizer and silica fume on the physical and mechanical behavior of concrete with recycled aggregates. Factorial design analysis shows that the developed mathematical models can be used to predict the physical and mechanical properties of concrete with RAC, superplasticizer, and silica fume. Doi: 10.28991/CEJ-2022-08-02-04 Full Text: PDF
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Gour, Chandra Prakash, Priyanka Dhurvey, and Nagaraju Shaik. "Optimization and Prediction of Concrete with Recycled Coarse Aggregate and Bone China Fine Aggregate Using Response Surface Methodology." Journal of Nanomaterials 2022 (October 7, 2022): 1–11. http://dx.doi.org/10.1155/2022/2264457.
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Construction recycled material is crucial for protecting natural resources and promoting sustainable human development in a rapidly industrializing world. Many administrations worldwide accepted that it is beneficial to use demolition waste in the concrete building industry to reduce manufacturing costs and minimize the use of virgin aggregates. However, control measures should be done as their mechanical properties are poorer than traditional aggregates. To overcome this problem, pozzolanic materials like bone chine can be incorporated, providing extra CSH gel, which improves mechanical strength. Therefore, this research is aimed at producing eco-friendly concrete, which can be used for medium-grade strength, using recycled construction waste (RCA) as coarse and bone china fine aggregate (BCA) as fine aggregate. Workability, density, compressive, split tensile, and flexural strength are used to compare the fresh and hardened properties of the concrete. Experimental and statistical research is employed in the current study to evaluate the impact of RCA and BCA on the performance of concrete. To simulate all measurable responses, including workability, density, compressive, flexural, and split strength, RSM (response surface methodology) was utilized. The CCD (Central Composite Design) approach in RSM was used to create and analyze mixes in an experiment. Based on the experiment’s results, mathematical models were designed and assessed using the analysis of variance test (ANOVA). The analysis of variance results demonstrated the statistical significance of each constructed model. Three-dimensional response surface plots created using established regression models were used to investigate the interaction between the respective variables and to optimize the mixing ratio. The results indicate that the optimum utilization of RCA is up to 40% and BCA up to 60% as coarse and fine aggregate replacement in concrete, respectively, which not only helps to reduce costs but also offers sustainability. Finally, it was concluded that the generated models might be employed by obtaining the maximum tested features of concrete to assure a quick mix design approach. To conduct the microstructure study, thin section techniques were used to observe a strong aggregate-matrix interaction.
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Shcherban’, E., A. Beskopylny, L. Mailyan, S. Stel’makh, and D. El’shaeva. "Mathematical modeling of mechanical properties of vibro-centrifuged fiber-reinforced concrete of variatropic structure." Journal of Physics: Conference Series 2131, no. 3 (December 1, 2021): 032090. http://dx.doi.org/10.1088/1742-6596/2131/3/032090.
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Abstract Today, one of the most relevant areas in the construction industry, linked to the requirements and provisions of the Strategy of Scientific and Technological Development, and in accordance with the priority areas of science and technology development, is the development and improvement of low-material, low-energy and low - resource-intensive technologies for the manufacture of concrete and reinforced concrete products and structures. In this regard, the technology of vibrocentrifugation, which allows to obtain concrete with an improved variatropic structure, is quite promising. In this work, the influence of the design parameters of the technological equipment and the parameters of the centrifugation modes on the integral strength characteristics of vibrocentrifugated fiber concrete was evaluated. In total, 13 samples of the annular section were manufactured and tested. Calculations of the integral strength characteristics of vibrocentrifugated fiber concrete depending on the height of the technological protrusions of the clamps and the angular rotation speed were performed by the method of orthogonal composite planning of the 2nd order using the MathCAD program. The mathematical method of planning the experiment is aimed at creating mathematical empirical models that determine the influence of the incoming variable factors on the strength characteristics. Thus, according to the results of experimental studies, the optimal height of the technological protrusions and the angular speed of rotation were determined. Thus, further regulation of technological factors in the manufacture of vibrocentrifugated products and structures will allow us to obtain the most effective ring-section structures with enhanced variatropy.
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Niyakovski, Alexander M., Uladzimir N. Ramaniuk, Аleksandr N. Chychko, and Yury V. Yatskevich. "Unsteady model of the hydration process of a reinforced concrete product at software-controlled heating." Doklady of the National Academy of Sciences of Belarus 63, no. 4 (September 13, 2019): 496–505. http://dx.doi.org/10.29235/1561-8323-2019-63-4-496-505.
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The development of mathematical models for design of the thermal technology equipment intended for accelerated hydration of concrete products is an urgent task of industrial heat power engineering. The introduction of mathematical modeling methods can reduce the time and the resources spent for the development of technological regimes that reduce energy consumption in the production of building structures and, ultimately, in the construction of buildings and structures for various purposes. There is not yet a generally accepted mathematical model of thermal processes occurring in thermal technological installations in the case of accelerated hardening of a three-dimensional concrete object. The purpose of this work is to develop an unsteady model of the concrete hydration process applied to a symmetrical three-dimensional reinforced concrete product at software-controlled heating. By using the numerical finite-volume method in the case of a 0.3 × 0.3 ×0.3 mcube, a three-dimensional feld of hydration in a concrete object at a given operation mode of a heater is calculated. The following heating mode was used: “heating–maintaining at a constant temperature–cooling”. The dependences of a temperature difference between reinforced and non-reinforced cubic products on the hardening time at the corresponding space points in the direction from the surface to the center of the product have been obtained. By the example of the numerical simulation results, it is shown that the evolution of the hydration degree at these points during the hardening of non-reinforced concrete differs from the hardening of reinforced concrete. The time dependences of heat treatment of a rate of temperature change and the hydration coefficient at the selected points of a product are presented. The obtained results are analyzed.
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Sun, Junbo, Jiaqing Wang, Zhaoyue Zhu, Rui He, Cheng Peng, Chao Zhang, Jizhuo Huang, Yufei Wang, and Xiangyu Wang. "Mechanical Performance Prediction for Sustainable High-Strength Concrete Using Bio-Inspired Neural Network." Buildings 12, no. 1 (January 10, 2022): 65. http://dx.doi.org/10.3390/buildings12010065.
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High-strength concrete (HSC) is a functional material possessing superior mechanical performance and considerable durability, which has been widely used in long-span bridges and high-rise buildings. Unconfined compressive strength (UCS) is one of the most crucial parameters for evaluating HSC performance. Previously, the mix design of HSC is based on the laboratory test results which is time and money consuming. Nowadays, the UCS can be predicted based on the existing database to guide the mix design with the development of machine learning (ML) such as back-propagation neural network (BPNN). However, the BPNN’s hyperparameters (the number of hidden layers, the number of neurons in each layer), which is commonly adjusted by the traditional trial and error method, usually influence the prediction accuracy. Therefore, in this study, BPNN is utilised to predict the UCS of HSC with the hyperparameters tuned by a bio-inspired beetle antennae search (BAS) algorithm. The database is established based on the results of 324 HSC samples from previous literature. The established BAS-BPNN model possesses excellent prediction reliability and accuracy as shown in the high correlation coefficient (R = 0.9893) and low Root-mean-square error (RMSE = 1.5158 MPa). By introducing the BAS algorithm, the prediction process can be totally automatical since the optimal hyperparameters of BPNN are obtained automatically. The established BPNN model has the benefit of being applied in practice to support the HSC mix design. In addition, sensitivity analysis is conducted to investigate the significance of input variables. Cement content is proved to influence the UCS most significantly while superplasticizer content has the least significance. However, owing to the dataset limitation and limited performance of ML models which affect the UCS prediction accuracy, further data collection and model update must be implemented.
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Subramani, T., and A. Periasamy. "Study on Behaviour of Stud Type Shear Connector in Composite Beam Using ANSYS." International Journal of Engineering & Technology 7, no. 3.10 (July 15, 2018): 54. http://dx.doi.org/10.14419/ijet.v7i3.10.15629.
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Composite plays a vital role in replacing the existing mild steel in reinforcement and exterior truss structure. This study proposed to design shear connector for joining concrete slab and steel section. Shear connectors has analyzed and predict the best connector for a particular composite beam with respect to static load and the amount of steel in the connector as a common aspect. The use of composite structures is increasingly present in civil construction works nowadays. Composite beams, especially, are structures which include substances, a metal phase placed in particular inside the tension region and a concrete phase, positioned in the compression go sectional location, both are related with the aid of steel gadgets called shear connectors. The main features of this connector are to permit the weight for the joint the beam-column, to restriction longitudinal slipping and uplifting on the factors interface the shear forces. Our project paper presents 3D numerical models of steel-concrete composite beams to simulate their structural behaviour, with emphasis on the beam column interface using Simulations software ANSYS 18.1 based on the Finite Element Method. Mostly these type of structures are widely used in the dynamic loading structures like bridges and high rise buildings.
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Gallyamova, Tat’yana R. "Probabilistic Model of the Reflectivity of Construction Materials of the Agroindustrial Complex." Elektrotekhnologii i elektrooborudovanie v APK 3, no. 44 (September 2021): 111–15. http://dx.doi.org/10.22314/2658-4859-2021-68-3-111-115.
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When developing modern lighting technologies for objects of the agro-industrial complex, the problem arises of assessing the contribution of reflected light to the normalized illumination. The reflective properties of the surfaces of materials are characterized by a reflection coefficient ρ, which reaches a value of 0.7. This allows us to consider the reflective surfaces as an additional light source and the possibility of reducing energy consumption costs. (Research purpose) The research purpose is in developing a mathematical model that allows us to estimate the spectral reflection coefficient ρ(λ) of materials of construction technologies of the agro-industrial complex in the ultraviolet and visible spectral regions. (Materials and methods) That the disadvantage of various models is the lack of an analytical method for calculating the reflection coefficient in a wide range of wavelengths. We used a probabilistic method to overcome this disadvantage. (Results and discussion) The developed mathematical model makes it possible to estimate the reflection coefficient of the rough surface of materials in a wide range of the spectrum. For concrete, the area of agreement between theory and experiment is in the wavelength range from 250 to 1000 nm. The saturation mode predicted by the theory (the independence of the reflection coefficient from the wavelength) at a reflection coefficient of 0.4 is consistent with the experimental values in the visible range of the spectrum for construction materials of the agro-industrial complex, in particular, gray textured concrete, gray facade paint, light wood, gray silicate brick, new plaster without whitewash. (Conclusions) In the case of normal light incidence, the developed mathematical model allows us to theoretically estimate the reflection coefficient of the rough surfaces of construction technologies of the agro-industrial complex. The proposed model can be used in the development and design of a system of technological lighting of large-area premises (for example, when keeping birds on the floor), as well as for developing recommendations for reducing the energy consumption of existing lighting systems.
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Li, Huihui, Guojie Zhou, and Jun Wang. "Selection of Ground Motion Intensity Measures and Evaluation of the Ground Motion-Related Uncertainties in the Probabilistic Seismic Demand Analysis of Highway Bridges." Buildings 12, no. 8 (August 8, 2022): 1184. http://dx.doi.org/10.3390/buildings12081184.
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Probabilistic seismic demand analysis (PSDA) is known as one of the critical intermediate steps in the performance-based earthquake engineering (PBEE) design framework. Accuracy of the PSDA is influenced by various sources of uncertainties and mostly by that stemming from the ground motion-related variabilities. By taking a representative reinforced concrete (RC) continuous girder bridge as the case study, twenty-eight commonly used seismic intensity measures (IMs) were investigated in terms of the effectiveness, efficiency, practicality, proficiency, and sufficiency assessments. Probabilistic seismic demand models (PSDMs) of several critical bridge engineering demand parameters (EDPs) were developed under both the near-field and far-field ground motions through the nonlinear time history analyses (NTHAs). In addition, effects of ground motion-related uncertainties, such as the bin-to-bin (BTB) and record-to-record (RTR) variabilities, on the PSDA of highway bridges were also investigated. It is concluded that (1) IM efficiency contributes significantly to reflecting the RTR variability of ground motions and an efficient IM may reduce the influence of RTR variability in the estimation of structural demands; (2) IM sufficiency reflects the statistical independence of IM and ground motion parameters, and a sufficient IM is helpful in rendering the prediction of structural demands; and (3) uncertainties stemming from both the BTB and RTR variabilities of the seismic records have significant influences on the PSDA and the developed PSDMs of highway bridges.
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Wang, Jiawei, and Quansheng Sun. "Experimental Study on Improving the Compressive Strength of UHPC Turntable." Advances in Materials Science and Engineering 2020 (July 18, 2020): 1–21. http://dx.doi.org/10.1155/2020/3820756.
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Purpose. In the recent years, horizontal rotation methods have been widely used for bridge construction, particularly for constructing overpass bridges on highways, railways, and shipping. However, bridges constructed using the swivel construction method bear several types of loads during the rotation process. Furthermore, the bridge turntable, which is the core force-bearing component of the structure, bears considerably large vertical pressure and horizontal frictional resistance. The present research proposes three strengthening methods when applying ultrahigh performance concrete (UHPC) materials to the turntable of a spherical hinge to improve structural reliability. Furthermore, the mechanical properties of the structure are evaluated using a unidirectional compressive strength test to provide a theoretical and experimental basis for the application of the UHPC material. Design/Methodology/Approach. To evaluate the mechanical performance of the turntable of a spherical hinge, scale models of six sets of UHPC turntables—steel tube-UHPC, stirrup-UHPC, and directional steel fiber UHPC—were constructed in the study. The compressive strengths of the turntable specimens were calculated after theoretical analysis. After obtaining the load-displacement curves of the cube specimens, the force characteristics of the turntable and the failure mechanism of the structure were analyzed by observing the failure mode of the specimens. Findings. The compressive strength of the steel tube-UHPC turntable was 207 MPa, which can completely replace the traditional steel turntable. In addition, the stirrup-UHPC turntable demonstrated a significant loading effect. However, the effect of the restraint radius of the stirrup needs to be considered during the design; otherwise, the loading effect is poor. Furthermore, a directional steel fiber UHPC turntable can improve the compressive strength to a certain extent. We summarize the failure mechanism of the spherical hinge turntable specimens that are expected to play a role in UHPC spherical hinge in engineering applications and construction monitoring. Originality/Value. To the best of our knowledge, this study is the first to employ the UHPC, steel tube-UHPC, stirrup-UHPC, and directional steel fiber spherical hinge turntables in the swivel construction of bridges. The compressive strength and mechanical characteristics of the UHPC structure meet the requirements of the turntable, and more importantly, the manufacturing process (on-site pouring) of the aforementioned UHPC turntable structures is relatively simple. Finally, the manufacturing cost of the turntables is expected to be reduced by more than 50% compared to those of traditional turntables.
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Meruane, Viviana, Sergio J. Yanez, Leonel Quinteros, and Erick I. Saavedra Flores. "Damage Detection in Steel–Concrete Composite Structures by Impact Hammer Modal Testing and Experimental Validation." Sensors 22, no. 10 (May 20, 2022): 3874. http://dx.doi.org/10.3390/s22103874.
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Steel–concrete composite systems are an efficient alternative to mid- and high-rise building structures because of their high strength-to-weight ratio when compared to traditional concrete or steel constructive systems. Nevertheless, composite structural systems are susceptible to damage due to, for example, deficient construction processes, errors in design and detailing, steel corrosion, and the drying shrinkage of concrete. As a consequence, the overall strength of the structure may be significantly decreased. In view of the relevance of this subject, the present paper addresses the damage detection problem in a steel–concrete composite structure with an impact-hammer-based modal testing procedure. The mathematical formulation adopted in this work allows for the identification of regions where stiffness varies with respect to an initial virgin state without the need for theoretical models of the undamaged structure (such as finite element models). Since mode shape curvatures change due to the loss of stiffness at the presence of cracks, a change in curvature was adopted as a criterion to quantify stiffness reduction. A stiffness variability index based on two-dimensional mode shape curvatures is generated for several points on the structure, resulting in a damage distribution pattern. Our numerical predictions were compared with experimentally measured data in a full-scale steel–concrete composite beam subjected to bending and were successfully validated. The present damage detection strategy provides further insight into the failure mechanisms of steel–concrete composite structures, and promotes the future development of safer and more reliable infrastructures.
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Fagen, M. E., and B. M. Phares. "Life-Cycle Cost Analysis of a Low-Volume Road Bridge Alternative." Transportation Research Record: Journal of the Transportation Research Board 1696, no. 1 (January 2000): 8–13. http://dx.doi.org/10.3141/1696-37.
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Life-cycle cost models offer engineers a means to evaluate the anticipated long-term economic performance of prospective design and construction alternatives. Traditionally, only initial investment costs and past experience were used to economically evaluate possible bridge designs. A more logical approach requires that all short- and long-term costs be considered in relation to project location, purpose, and performance specifications. The primary objective of life-cycle cost analysis is to evaluate the total ownership cost of all suitable alternatives. Recent reports indicate that a significant number of the nation’s bridges are either structurally deficient or functionally obsolete. In Iowa, a large portion of these types of bridges are on the secondary road system and fall under the jurisdiction of county engineers. Typically, Iowa county engineers have limited resources. In response to this, a bridge-replacement system was developed that county engineers can design and build with limited staff. The system, which is made up of precast (PC) double T units, involves the fabrication of PC units that consist of two steel beams connected by a thin concrete deck. To illustrate that this bridge system may be an economically viable bridge-replacement alternative for use on low-volume county roads, a life-cycle cost analysis was completed for an actual replacement-repair-rehabilitation project. Various alternatives were economically analyzed and compared with the steel beam PC unit bridge alternative. This analysis indicates that, when lower-cost salvaged steel beams and county work forces are used, the steel beam PC unit bridge can be a viable low-volume road bridge alternative.
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ZHARNITSKIY, V. YA, and A. P. SMIRNOV. "MATHEMATICAL MODEL OF MATERIALS OF STRUCTURES AND ELEMENTS OF RESTORED SOIL DAMS FOR NUMERICAL CALCULATIONS." Prirodoobustrojstvo, no. 4 (2021): 46–51. http://dx.doi.org/10.26897/1997-6011-2021-4-46-51.
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Identified in the process of analyzing the operation of the structure, in the conditions of its operation, allow to assess the actual reserves of the bearing capacity of the structure and take effective measures to restore the operational parameters. The main criteria influencing the choice of mathematical models of materials for structures and elements of soil dams are more consistent with the model of the equation of state connecting the components of stress and strain tensors, as well as the rate of their change, which are obtained and tested for numerical calculations and have a full set of constants for materials used in the calculations of earth dams, the choice of their structures (concrete,reinforced concrete, soils, etc.). Reliable operation of soil dams is possible only if all proper conditions are met. The causes of dam accidents and their damage must be known not only to eliminate errors at the design and construction stages, but also during their operation. In order to exclude the negative impact of operational factors on the safety of soil HTS, it is necessary not only to strictly observe the rules of technical operation and take measures to exclude the possibility of an emergency situation during technological operations at facilities, but also to have methods for predictive justification of the restoration of strength and operational indicators of structures and elements of soil dams.
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Khed, Veerendrakumar C., Vyshnavi Pesaralanka, Musa Adamu, Yasser E. Ibrahim, Marc Azab, Achyutha Kumar Reddy, Ahmad Hakamy, and Ahmed Farouk Deifalla. "Optimization of Graphene Oxide Incorporated in Fly Ash-Based Self-Compacting Concrete." Buildings 12, no. 11 (November 17, 2022): 2002. http://dx.doi.org/10.3390/buildings12112002.
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Self-compacting concrete (SCC) was developed to overcome the challenges of concrete placement in dense or congested reinforcement structure, where the concrete can flow under its own weight to fill the densely reinforced structure. However, production of SCC mostly involves the use of high cement to achieve the desired strength. Therefore, to reduce the needed amount of cement, pozzolanic materials such as fly ash can be used to partially replace cement. However, fly ash has been reported to decrease the strengths of concrete especially at early ages. In this study, a self-compacting concrete (SCC) was developed with fly ash as a basic replacement material considering the efficiency of fly ash and incorporating graphene oxide (GO) as a cement additive to counteract the negative effect of fly ash. Response surface methodology (RSM) was utilized for designing the experiments, investigating the effects of fly ash and GO on SCC properties, and developing mathematical models for predicting mechanical properties of SCC. The ranges of fly ash and graphene oxide were 16.67 to 35% and zero to 0.05%, respectively. Statistical analysis was performed by using Design Expert software (version 11.0, Stat Ease Inc., Minneapolis, MS, USA). The results showed that fly ash had a positive effect while GO had a negative effect on the workability of SCC. The incorporation of fly ash alone decreased the compressive strength (CS), splitting tensile strength (STS) and flexural strength (FS), and additionally, increased the porosity of SCC. The addition of GO to fly ash-based SCC reduced its porosity and enhanced its mechanical strengths which was more pronounced at early ages. The developed models for predicting the mechanical strengths of fly ash-based SCC containing GO have a very high degree of correlation. Therefore, the models can predicts the strengths of SCC using fly ash and GO as the variables with a high level of accuracy. The findings show that based on the EFNARC guidelines, up to 35% of fly ash can be used to replace cement in SCC to achieve a mix with satisfactory flowability and deformability properties
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Loktev, A. A., V. V. Korolev, D. A. Loktev, D. R. Shukyurov, P. A. Gelyukh, and I. V. Shishkina. "Perspective constructions of bridge overpasses on transport main lines." Vestnik of the Railway Research Institute 77, no. 6 (December 30, 2018): 331–36. http://dx.doi.org/10.21780/2223-9731-2018-77-6-331-336.
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Abstract. When designing bridges on motorways and railways, conventional beam or trussed design schemes of structures made of steel or reinforced concrete are used, but at present there is a significant increase in the speeds of motion of individual vehicles, axial loads and total train weight increase, and temporary intervals between trains. These factors lead to a significant increase in dynamic effects and necessitate the use of non-classical design schemes for artificial structures of transport infrastructure. In this study, it is proposed to take a threespan arch bridge with suspended central span structure as the basis for unified bridge overpass. Such an arrangement will allow changing the design length of the central span in a fairly wide range, reducing the total number of supports with an increase in the total length of the bridge overpass, and using a similar design as a double-track railroad, two- or four-lane motorway bridge. Calculations carried out and the results obtained for calculating displacements, internal forces and stresses in the units and elements of the proposed bridge overpass design allow concluding about the allowable limit values of the values found, sufficiently uniform load of all its main elements, the absence of strongly marked large-scale stress concentrators. Proposed design allows setting different sizes of spans during the design, reducing the number or even avoiding the installation of channel supports, adapting this structure for the passage of both rail and road transport. Design of the bridge, mathematical model of which is described in detail in the article, can be manufactured at the factory, and then delivered to the installation site and mounted there, which significantly reduces the final construction cost and makes it a profitable solution, for example, for arranging railway interchanges at different levels.