Статті в журналах: "Concrete construction Models"

1

Le, Hoai-Bao, Quoc-Bao Bui, and Luping Tang. "Geopolymer Recycled Aggregate Concrete: From Experiments to Empirical Models." Materials 14, no. 5 (March 3, 2021): 1180. http://dx.doi.org/10.3390/ma14051180.

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Ordinary cement concrete is a popular material with numerous advantages when compared to other construction materials; however, ordinary concrete is also criticized from the public point of view due to the CO2 emission (during the cement manufacture) and the consumption of natural resources (for the aggregates). In the context of sustainable development and circular economy, the recycling of materials and the use of alternative binders which have less environmental impacts than cement are challenges for the construction sector. This paper presents a study on non-conventional concrete using recycled aggregates and alkali-activated binder. The specimens were prepared from low calcium fly ash (FA, an industrial by-product), sodium silicate solution, sodium hydroxide solution, fine aggregate from river sand, and recycled coarse aggregate. First, influences of different factors were investigated: the ratio between alkaline activated solution (AAS) and FA, and the curing temperature and the lignosulfonate superplasticizer. The interfacial transition zone of geopolymer recycled aggregate concrete (GRAC) was evaluated by microscopic analyses. Then, two empirical models, which are the modified versions of Feret’s and De Larrard’s models, respectively, for cement concretes, were investigated for the prediction of GRAC compressive strength; the parameters of these models were identified. The results showed the positive behaviour of GRAC investigated and the relevancy of the models proposed.

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Teijón-López-Zuazo, Evelio, Jorge López-Rebollo, Luis Javier Sánchez-Aparicio, Roberto Garcia-Martín, and Diego Gonzalez-Aguilera. "Compression and Strain Predictive Models in Non-Structural Recycled Concretes Made from Construction and Demolition Wastes." Materials 14, no. 12 (June 9, 2021): 3177. http://dx.doi.org/10.3390/ma14123177.

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This work aims to investigate different predictive models for estimating the unconfined compressive strength and the maximum peak strain of non-structural recycled concretes made up by ceramic and concrete wastes. The extensive experimental campaign carried out during this research includes granulometric analysis, physical and chemical analysis, and compression tests along with the use of the 3D digital image correlation as a method to estimate the maximum peak strain. The results obtained show that it is possible to accurately estimate the unconfined compressive strength for both types of concretes, as well as the maximum peak strain of concretes made up by ceramic waste. The peak strain for mixtures with concrete waste shows lower correlation values.

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Matejević-Nikolić, Biljana, and Lazar Živković. "Comparative Representation of Two Models for Predicting the Productivity of Column and Wall Concreting Process." Buildings 12, no. 11 (October 28, 2022): 1809. http://dx.doi.org/10.3390/buildings12111809.

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One of the most important tasks of managing the construction process is to achieve the highest possible productivity. The productivity that can be achieved on a construction site depends on a number of influencing factors and on the type of work that is executed. Concrete works are a crucial activity when constructing high-rise buildings built in the RC frame structural system. Therefore, it is very important to adequately manage the concreting process in order to meet the set deadlines and reduce costs. This paper presents an approach for predicting the productivity of the concreting process based on the conducted quantitative research, by recording the concreting process on construction sites of buildings in Niš, Serbia. The concreting of reinforced concrete columns and walls on seven construction sites was recorded for 20 months. The total amount of fresh concrete that is built into the elements is 848 m3 and the total duration is 114 h of work. Factors that can affect productivity have been identified and, by applying the multiple linear regression and simulation methods and techniques and using the discrete event method and the agent-based method, models have been developed to predict the productivity of the concreting of reinforced concrete columns and walls. An analysis of the developed models was performed, and a comparative presentation was provided.

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Červenka, Vladimír, and Radomír Pǔkl. "Computer Models of Concrete Structures." Structural Engineering International 2, no. 2 (May 1992): 103–7. http://dx.doi.org/10.2749/101686692780615905.

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Ungerer, Tobias. "Extending structural priming to test constructional relations: Some comments and suggestions." Yearbook of the German Cognitive Linguistics Association 10, no. 1 (November 1, 2022): 159–82. http://dx.doi.org/10.1515/gcla-2022-0008.

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Abstract Structural priming is a promising tool for testing similarity relations between constructions, but its applicability to larger-scale models of constructional networks is still limited. This article outlines the following two limitations of previous priming studies: first, they largely focus on priming between alternating constructions; and second, they often test the relations between instances of the same construction rather than between instances of different constructions. Three strategies are suggested for how future priming research could overcome these limitations. Concrete ideas for experimental setups are presented, and their benefits and limitations are addressed.

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Ben Ammar, Ben Khadda. "Valuation of Palm Fibers in the Formulation of Prefabricated Concrete in Southern Algeria." Key Engineering Materials 925 (July 11, 2022): 3–8. http://dx.doi.org/10.4028/p-t2ileb.

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Algeria has known various models of construction. The general observation is the failure of construction models used not only for their inability to meet the growing demand for housing, but also for the destruction of the architectural and urban landscape. Considering the ability of natural fibers improve the mechanical properties and durability of concrete, a renewable resource and permanently available. To this end, researchers have started to search for the most durable materials that respect the environment. The objective of this research is the study of the effect of date palm fibers in cementitious compositions with various proportions on the mechanical characteristics of prefabricated concretes in southern Algeria. The experimental study focuses on the use of local materials (CEMII Class 42.5 R cement, sand, gravel (7/15 and 15/25) and palm fiber with a water/cement ratio of 0.55). The results show that fiber concrete with a length of 5 mm and a dosage of 0.5% is beneficial for prefabricated fiber concrete.

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Van Eecke, Paul, and Katrien Beuls. "Exploring the Creative Potential of Computational Construction Grammar." Zeitschrift für Anglistik und Amerikanistik 66, no. 3 (September 25, 2018): 341–55. http://dx.doi.org/10.1515/zaa-2018-0029.

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AbstractComputational construction grammar aims to provide concrete processing models that operationalise construction grammar accounts of the different aspects of language. This paper discusses the computational mechanisms that allow construction grammar models to exhibit, to a certain extent, the creativity and inventiveness that is observed in human language use. It addresses two main types of language-related creativity. The first type concerns the ‘free combination of constructions,’ which gives rise to the open-endedness of language. The second type concerns the ‘appropriate violation of usual constraints’ that permits language users to go beyond what is possible when adhering to the usual constraints of the language, and be truly creative by relaxing these constraints and by introducing novel constructions. All mechanisms and examples discussed in this paper are fully operationalised and implemented in Fluid Construction Grammar.

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Lazarev, Yuriy, Oleg Krotov, Svetlana Belyaeva, and Marina Petrochenko. "3D environmentally friendly concrete printing model preparation." E3S Web of Conferences 175 (2020): 11024. http://dx.doi.org/10.1051/e3sconf/202017511024.

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This article considers ways of the construction printing of models for agriculture, road, civil and also industrial construction using concrete mixtures. For acquaintance with technology, the architectural element with width of layer of 4 cm and 8 cm all model high has been taken with height of one layer of 2 cm. This model has been prepared with use of two packages of the program complexes having different functionality, namely AutoCAD+SheetCAM+Mach3, the second Sketch-Up+Simplify3D. Each software package was used for design of model in 2D or 3D perspectives, division of model into layers, identical on height, by means of technology of slicer, and also for creation of task of the model printing by concrete for the construction printer of model S 6044. Ready mixes for geopolymer concrete have been taken. By results of the printing, comparison of quality of the models printed on the construction printer and technology of each package of program complexes have been made. The printing of models has shown that quality of the printing is identical. In this case, the second method using a bundle of 2 programs (SketchUp + Simplify3D), which allows printing volumetric models of any shape both in plan and in the future, has an advantage.

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9

Zhao, Nan, Chang Ming Hu, and Wen Yan. "Research and Statistic Analysis on Construction Loads of Multistory Frame R.C Buildings." Advanced Materials Research 368-373 (October 2011): 1531–34. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.1531.

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In order to control the safety of R.C structure, the construction loads of multistory frame reinforced concrete buildings in xi’an were selected as the research objective. Based on the characteristic of construction loads, the survey on the work site had carried on during the construction progress. Variation of concrete dead weight had been discussed. And the mathematics models of live loads in different stages of construction process for reinforced concrete buildings were proposed through statistic analysis. The standard values of construction live loads were suggested at last.

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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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11

LaFave, James M., and James K. Wight. "Reinforced Concrete Wide-Beam Construction vs. Conventional Construction: Resistance to Lateral Earthquake Loads." Earthquake Spectra 17, no. 3 (August 2001): 479–505. http://dx.doi.org/10.1193/1.1586185.

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Experiments and analyses were conducted to address concerns about performance of reinforced concrete connections with shallow, wide beams subjected to lateral earthquake loading and to compare behavior of wide beam connections to that of conventional connections. Two wide beam-column-slab connections and one conventional beam-column-slab connection were subjected to cycles of reversing lateral displacements up to 5% drift. The conventional beam and wide beam connections exhibited similar overall load-displacement behavior, with similar beam plastic hinge development. The wide beam connections dissipated almost as much energy as the conventional beam connection and had greater slab participation and less joint and beam shear cracking than the conventional beam connection. Experimentally determined wide beam connection stiffness was closer to the conventional beam connection stiffness than had been predicted. Refined models were developed, with features such as rigid end offsets for wide beam connections, to better represent observed behavior. Nonlinear models were also developed that accurately captured differences in energy dissipation as well as stiffness.

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12

Kozniewski, Edwin, and Zygmunt Orlowski. "EXTENDED LINEAR PROGRAMMING IN MODELS OF LOCATION OF CONCRETE MIX PRODUCTION PLANTS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 11, no. 4 (December 31, 2005): 289–97. http://dx.doi.org/10.3846/13923730.2005.9636360.

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The paper discusses the location problem of production plants exemplified by concrete mix production plants (Ist model), taking into consideration the demand variability in time (IInd model), and the analytical method of the localization of industrial plant with a considerable amount of transportation costs of concrete mix and concrete aggregate (IIIrd model). Changes in demand for concrete mix in time t lead to changes in plants’ location. Assuming that there exist concrete mix production plants, one should make a simulation of demand for concrete mix which occurs at the time t The presented models are the essential generalisation of the problem discussed in the earlier papers. The matrix of construction costs must be always defined as a four‐dimensions vector (the set of four values): the production plant construction cost, the cost of plant's modernisation (which is the result of changing demand for concrete mix), the cost of liquidation (dismantling) of a production plant or the cost of moving of an existing production plant. Three new generalised notions concerning the classical linear programming (mixed programming, mixed programming with time and two‐optimised conjugate linear system) have been introduced. The algorithms describing the above‐mentioned models of location changes were suggested, and programmes solving the location problems were prepared in PASCAL.

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13

RUBIN, O. D., S. E. LISICHKIN, and O. V. ZYUZINA. "THE INFLUENCE OF BASALT-COMPOSITE PRESTRESSED REINFORCEMENT ON THE OPERATION OF LOW-REINFORCED CONCRETE STRUCTURES WITH INTERBLOCK CONSTRUCTION JOINTS." Prirodoobustrojstvo, no. 5 (2020): 50–59. http://dx.doi.org/10.26897/1997-6011-2020-5-50-59.

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It is proposed to use prestressed basalt composite reinforcement to strengthen reinforced concrete structures of hydraulic structures. In order to substantiate technical reinforcement of reinforced concrete structures of hydraulic structures with prestressed basalt composite inforcement, experimental studies were carried out. For experimental studies, reinforced concrete beam-type structures with vertical interblock construction joints were adopted.The results of experimental studies of reinforced concrete models of beam type with interblock joints reinforced with prestressed basalt composite reinforcement by the method of tension “on concrete”are presented. The models are tested for bending moment and transverse force. A special character of cracking is noted; full restoration of the bearing capacity of reinforced concrete structures, weakened by interblock construction joints, was recorded due to the reinforcement of prestressed basalt composite reinforcement.

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14

Tang, Qing Rong, and Zhi Qiang Fu. "Time-Varying Law Experimental Research of the Interaction of Concrete Structure and Formwork Support during the Construction Period." Applied Mechanics and Materials 488-489 (January 2014): 466–69. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.466.

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Research for mechanism of concrete structure interacting with formwork support by manufacturing 2 test models of two-layer and single-span reinforced concrete frame at laboratory,and analysis interaction performance between concrete structure and formwork support and the influence of construction period,curing time of concrete and load on mechanical performance of formwork support system during the construction period.Research data shows:formwork support system interacted with concrete structure is a linear system when live load applied is smaller then crack load calculated according to mechanical indicators of loading-age concrete;load applied by formwork support system decreases with develop of curing time of concrete and removal of bottom support and construction period extension;it is also effected by environmental temperature.

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15

Lee, K. M., Y. B. Lee, C. S. Shim, and K. L. Park. "Bridge information models for construction of a concrete box-girder bridge." Structure and Infrastructure Engineering 8, no. 7 (July 2012): 687–703. http://dx.doi.org/10.1080/15732471003727977.

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Zhang, Ji, and Jie Li. "Construction of homogeneous loading functions for elastoplastic damage models for concrete." Science China Physics, Mechanics and Astronomy 57, no. 3 (January 17, 2014): 490–500. http://dx.doi.org/10.1007/s11433-013-5188-0.

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Maqsoom, Ahsen, Bilal Aslam, Muhammad Ehtisham Gul, Fahim Ullah, Abbas Z. Kouzani, M. A. Parvez Mahmud, and Adnan Nawaz. "Using Multivariate Regression and ANN Models to Predict Properties of Concrete Cured under Hot Weather: A Case of Rawalpindi Pakistan." Sustainability 13, no. 18 (September 10, 2021): 10164. http://dx.doi.org/10.3390/su131810164.

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Concrete is an important construction material. Its characteristics depend on the environmental conditions, construction methods, and mix factors. Working with concrete is particularly tricky in a hot climate. This study predicts the properties of concrete in hot conditions using the case study of Rawalpindi, Pakistan. In this research, variable casting temperatures, design factors, and curing conditions are investigated for their effects on concrete characteristics. For this purpose, water–cement ratio (w/c), in-situ concrete temperature (T), and curing methods of the concrete are varied, and their effects on pulse velocity (PV), compressive strength (fc), depth of water penetration (WP), and split tensile strength (ft) were studied for up to 180 days. Quadratic regression and artificial neural network (ANN) models have been formulated to forecast the properties of concrete in the current study. The results show that T, curing period, and moist curing strongly influence fc, ft, and PV, while WP is adversely affected by T and moist curing. The ANN model shows better results compared to the quadratic regression model. Furthermore, a combined ANN model of fc, ft, and PV was also developed that displayed higher accuracy than the individual ANN models. These models can help construction site engineers select the appropriate concrete parameters when concreting under hot climates to produce durable and long-lasting concrete.

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Berczyński, Stefan, and Tomasz Wróblewski. "Vibration of Steel–Concrete Composite Beams Using the Timoshenko Beam Model." Journal of Vibration and Control 11, no. 6 (June 2005): 829–48. http://dx.doi.org/10.1177/1077546305054678.

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In this paper we present a solution of the problem of free vibrations of steel–concrete composite beams. Three analytical models describing the dynamic behavior of this type of constructions have been formulated: two of these are based on Euler beam theory, and one on Timoshenko beam theory. All three models have been used to analyze the steel–concrete composite beam researched by others. We also give a comparison of the results obtained from the models with the results determined experimentally. The model based on Timoshenko beam theory describes in the best way the dynamic behavior of this type of construction. The results obtained on the basis of the Timoshenko beam theory model achieve the highest conformity with the experimental results, both for higher and lower modes of flexural vibrations of the beam. Because the frequencies of higher modes of flexural vibrations prove to be highly sensitive to damage occurring in the constructions, this model may be used to detect any damage taking place in such constructions.

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Thai, Hong Nam, Ken Kawamoto, Hoang Giang Nguyen, Toshihiro Sakaki, Toshiko Komatsu, and Per Moldrup. "Measurements and Modeling of Thermal Conductivity of Recycled Aggregates from Concrete, Clay Brick, and Their Mixtures with Autoclaved Aerated Concrete Grains." Sustainability 14, no. 4 (February 20, 2022): 2417. http://dx.doi.org/10.3390/su14042417.

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Cool road pavements contribute to mitigating urban heat islands. To evaluate the heat balance in paved surfaces and to select appropriate road construction materials that help suppress heat islands, an accurate understanding of heat transport parameters such as thermal conductivity (λ) and heat capacity (HC) is important. Recycled aggregates from construction and demolition waste, including scrap construction materials and industrial by-products, are often used for road construction; however, λ and HC of recycled aggregates especially for roadbeds are not fully understood. This study involved a series of laboratory tests to measure λ and HC of recycled concrete and clay brick aggregates (<40 mm) and their mixtures with autoclaved aerated concrete grains (<2 mm) under varied moisture conditions. The measured λ and HC increased with increasing volumetric water content (θ). Closed-form models for estimating λ(θ) were proposed using normalized thermal conductivity (λe) and effective saturation (Se). The new λe(Se) models performed well for the measured data compared to previously proposed models and would be useful to evaluate λ of recycled aggregates for roadbed materials.

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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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Vujic, Jelena. "Deconstructing English Articles A Construction Grammar Approach To Teaching Articles In English." Romanian Journal of English Studies 12, no. 1 (November 1, 2015): 67–81. http://dx.doi.org/10.1515/rjes-2015-0009.

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Abstract The semantics of the articles is crucial for their proper usage in L2 speakers. However, we believe that for their proper acquisition a pairing of concrete form and concrete meaning must take place. In other words, a schema must be created for various meanings of articles. Therefore, in this paper English articles will be viewed from the aspect of Construction grammar. Working within the framework of CxG we will perceive the noun phrases of the type a/the+ N as lexico-syntactic meaningful constructions where the articles attribute a particular meaning to the noun(s) they determine. Together they constitute Determination (article) Construction. Each particular meaning of the articles can be conceptualized and adequate abstract constructional schemas and subschemas as a schematic pairing of form and meaning can be created. In addition, we will use the Serbo-Croatian semantic equivalents of English articles such as indefinite pronouns neki, poneki, koji, kakav, numerals jedan, ijedan, adverbs nekako and makar, demonstrative determiners onaj, adjectives, negative forms ni, nikakav, possessive pronominals and many more. They will serve as a starting point for offering possible constructional schema models for meaningful constructions a/the +N. Other meanings and usages of the articles will be treated in the same way. We believe that by initializing the conceptualization and encouraging schema development in ESL/EFL students whose mother tongue is Serbo-Croatian reasonable strategies for article choice in English can be provided This is aimed at enhancing their learning process and facilitating acquisition of articles through their understanding and association with concrete lexemes (which would ideally lead to their conceptualization) rather than through abstract concepts of specificity and (in)definiteness as previous studies have done.

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Oh, CL, SW Lee, MZ Mohd Raizamzamani, AR Azerai, and Y. Norrul Azmi. "Finite element analysis of high strength reinforced concrete beams." MATEC Web of Conferences 250 (2018): 03007. http://dx.doi.org/10.1051/matecconf/201825003007.

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Development of high strength concrete as a new ecological construction material to sustain the gradually expanding construction industry has arisen. This paper presents nonlinear finite element analysis of three-dimensional high strength reinforced concrete beams using ABAQUS. The uniaxial compressive strength for the beam models were taken from the existing experimatal data on high strength concrete cubes. Eurocode 2 was also used to establish material parameters for the constitutive models for concrete and reinforcing bars. In this study, two 150mm x 200mm x 1200mm simply supported rectangular concrete beam models subjected to loads at different shear span to effective depth ratios (a/d = 1.0 and 2.0) were analysed. Numerical results were validated with the existing experimental data specifically on the load-deflection responses and von mises stresses. It was found that the finite element results show greater than 70% agreement with the experimental results.

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Singh, Ranjodh, and Harvinder Singh. "Shear Strength Models for Steel Fibre Reinforced Concrete Beams: Current Scenario." Civil Engineering Journal 7, no. 2 (February 1, 2021): 399–406. http://dx.doi.org/10.28991/cej-2021-03091661.

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This review paper presents a comprehensive comparative analysis of various studies conducted on the shear strength of Self-compacting Concrete (SCC) and Normally Vibrated Concrete (NVC) in order to determine the sustainability and affordability of SCC as a construction material. Compaction is the main factor in concrete production. NVC needs compaction and vibration to remove the entrapped air which is both expensive and time-consuming. But SCC has flow ability and passing ability. Although SCC takes a greater amount of paste content, thereby raising the cost of building material, yet the use of such waste material as fly ash, silica, etc. comes in handy as paste content. Thus, the advantages offered by SCC in terms of increased strength as well as cost reduction makes it a highly desirable construction material. The review has selected the works of some eminent scholars on concrete and has analyzed them through individual as well as comparative perspective. A close analysis has helped filter out relevant works for the current study. This process of selection has proved helpful to include most standard works available in the review. Major findings have been enlisted at the end and ways to improve concrete behaviour have been suggested. Doi: 10.28991/cej-2021-03091661 Full Text: PDF

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Лебедев, Владимир, Vladimir Lebedev, Галина Беликова, and Galina Belikova. "MODELING CONSTRUCTION OF MONOLITHIS CONCRETE FLOORS TAKING INTO ACCOUNT ORGANIZATIONAL - TECHNOLOGICAL RELIABILITY." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 2, no. 3 (February 9, 2017): 51–56. http://dx.doi.org/10.12737/article_58db88f9079c1.

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Work out the organizational and technological models and carried out in-line construction complex engineering preparation of construction production construction of monolithic concrete floors, taking into account the organizational and technological reliability

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Лебедев, Vladimir Lebedev, Беликова, and Galina Belikova. "MODELING CONSTRUCTION OF MONOLITHIS CONCRETE FLOORS TAKING INTO ACCOUNT ORGANIZATIONAL - TECHNOLOGICAL RELIABILITY." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 2, no. 3 (April 4, 2017): 51–56. http://dx.doi.org/10.12737/article_58e23dd2e90fd8.76634873.

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Work out the organizational and technological models and carried out in-line construction complex engineering preparation of construction production construction of monolithic concrete floors, taking into account the organizational and technological reliability

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Abduljabar Abdulla, Nwzad. "Strength models for uPVC-confined concrete." Construction and Building Materials 310 (December 2021): 125070. http://dx.doi.org/10.1016/j.conbuildmat.2021.125070.

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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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Mesfin, Woldeamanuel Minwuye, Soojin Cho, Jeongmin Lee, Hyeong-Ki Kim, and Taehoon Kim. "Deep-Learning-Based Segmentation of Fresh or Young Concrete Sections from Images of Construction Sites." Materials 14, no. 21 (October 22, 2021): 6311. http://dx.doi.org/10.3390/ma14216311.

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The objective of this study is to evaluate the feasibility of deep-learning-based segmentation of the area covered by fresh and young concrete in the images of construction sites. The RGB images of construction sites under various actual situations were used as an input into several types of convolutional neural network (CNN)–based segmentation models, which were trained using training image sets. Various ranges of threshold values were applied for the classification, and their accuracy and recall capacity were quantified. The trained models could segment the concrete area overall although they were not able to judge the difference between concrete of different ages as professionals can. By increasing the threshold values for the softmax classifier, the cases of incorrect prediction as concrete became almost zero, while some areas of concrete became segmented as not concrete.

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29

Dong, Cheng Xiu. "Grey Interval Model of the Temperature Rise Prediction of Massive Concrete in Construction Process." Applied Mechanics and Materials 357-360 (August 2013): 631–34. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.631.

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During the construction process of massive concrete, the construction must forecast and control the temperature forming of massive concrete in order to avoid the temperature crack owing to the thermal stress caused by the concrete heat. The discussion on the concept of grey system interval and grey number predication applies to the temperature rise prediction of massive concrete in the construction process. The previous temperature rise data is divided into the white part and grey part based on real numbers. And the interval grey number forecast computing models are established, so we can finish the temperature rise prediction during construction process. The forecasting results of case show that, this model has fast convergence and remarkable precision. Then, it is possible to realize the accurate temperature rise prediction of massive concrete.

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30

BAKLYKOV, I. V. "Numerical analysis of the behavior of bendable reinforced concrete beams made of lightweight high-strength concrete with different reinforcement coefficients." Prirodoobustrojstvo, no. 4 (2022): 84–89. http://dx.doi.org/10.26897/1997-6011-2022-4-84-89.

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Lightweight high-strength concrete structures are currently spreading, primarily in civil engineering and bridge construction. High-strength lightweight aggregate concrete has advantages over heavyweight concrete when used in structures that must have high strength and buoyancy due to lower density and high enough strength. In this regard, it seems appropriate to use lightweight high-strength concrete in hydraulic engineering construction in offshore oil platforms and dry dock gate. In the presented work, computational studies of the stress-strain state of reinforced concrete beam structures made of light high-strength concrete have been carried out. To model the behavior of reinforced concrete beams made of lightweight high-strength concrete, spatial finite-element models have been developed. Researches were performed in the software «ANSYS». The developed models are verified by data of full-scale tests of beams with two reinforcement coefficients: 0.036 and 0.015. The performed studies allowed making a conclusion about the difference in behavior and destruction of beams at two reinforcement coefficients.

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31

Gamal, Yasser A. S., and Mostafa Abd Elrazek. "Evaluation of the seismic performance of lightweight concrete multistory buildings." IOP Conference Series: Materials Science and Engineering 1269, no. 1 (November 1, 2022): 012004. http://dx.doi.org/10.1088/1757-899x/1269/1/012004.

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In recent years, lightweight concrete has become very popular in the construction industry. And, its usage can lead to reduced costs and time. Therefore, different types of concrete (lightweight (LC), heavyweight (HC), and ordinary concrete (OC)) have been investigated to comprehend their response to earthquake load. Also, the comparison between their responses has been considered for getting the best response for various materials in construction work. The results prove that building models with LC are more resistant to earthquakes than the other types due to the reduction in the weight of buildings. Consequently, it has a role in resisting seismic forces. Furthermore, the combination of different concrete in the structural elements is another important criterion to be considered in thesis. The findings demonstrate that the responses in models for OCC-LCR (ordinary concrete for the column and light concrete for the roof) and LCC-OCR (light concrete column and ordinary concrete roof) have fewer values than the other types.

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32

Najjar, Yacoub M., Imad A. Basheer, and Richard L. McReynolds. "Neuronet-Based Approach To Modeling the Durability of Aggregate in Concrete Pavement Construction." Transportation Research Record: Journal of the Transportation Research Board 1582, no. 1 (January 1997): 29–33. http://dx.doi.org/10.3141/1582-05.

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The durability of aggregate used in concrete pavements construction is commonly assessed by subjecting small concrete beams containing the aggregate to cyclic freezing and thawing. The durability of aggregate and concrete specimens is quantified by measuring the durability factor (DF) and percent expansion (EXP). A typical durability test may last 3 to 5 months and involve high costs. It was assumed that the durability of aggregate used as a constituent in concrete elements may be related to some easily measured physical properties of the aggregate. A data base obtained from records of the Kansas Department of Transportation contained a total of 750 durability tests. The observed wide scatter in the experimental data when DF or EXP is related to one physical parameter suggested the use of artificial neural networks to model durability. Neural network models were developed to predict durability of aggregate from five basic physical properties of the aggregate. The models were found to classify the aggregates with regard to their durability with a relatively high accuracy. In addition, the models were used to assess the reliability of prediction. To illustrate the use of the models, numerical examples are presented.

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33

Lee, Duk Gyoo. "Construction factors affecting as-built roughness of Portland cement concrete pavement construction." Canadian Journal of Civil Engineering 32, no. 5 (October 1, 2005): 906–12. http://dx.doi.org/10.1139/l05-044.

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This paper investigates the significant construction factors affecting the as-built roughness of Portland cement concrete (PCC) pavement. The panel data analysis uses as-built roughness measurements and related construction factors for reconstructed, replaced, and resurfaced PCC pavement projects in Wisconsin from 1998 to 2002. Construction factors are divided into two categories in this analysis: (1) pavement characteristics and (2) contractor's quality-based performance. The analysis utilizes the fixed effects and random effects modeling techniques to identify the significant variables in the model. The research shows that the fixed effects model, of all proposed models, provides the best estimate on the basis of Akaike's information criterion (AIC). The results indicate that pavement characteristics and contractor's quality-based past performance significantly affect as-built roughness. The findings also show that geographic locations are strongly significant.Key words: panel (longitudinal) data analysis, as-built roughness, international roughness index (IRI), Akaike's information criterion (AIC), construction factor, Portland cement concrete (PCC) pavement, highway construction.

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Behzodi, B., K. A. Andrianov, and A. F. Zubkov. "Modeling of thermal processes in construction of nonrigid pavements using bitumen concrete mixes." Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture 23, no. 2 (April 30, 2021): 146–61. http://dx.doi.org/10.31675/1607-1859-2021-23-2-146-161.

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The remoteness of the construction site from the production base, large volumes of work, insufficient productivity of asphalt concrete plants for the preparation of hot asphalt concrete mixtures makes urgent the use of cold bitumen concrete mixes for the road construction. The preliminary mix preparation on the production sites with preservation of its properties for several months allows to increase the duration of the construction season. Purpose. Quality improvement of construction of non-rigid road surfaces using cold bitumen concrete mixes. Materials and methods. Models of road pavement structure based on cold bitumen concrete mixes are proposed to clarify the influence of the structural, climatic, technological and thermophysical properties of materials on the pavement quality. Research results. It is shown that the construction of road surfaces using cold bitumen concrete mixes even at positive ambient temperatures, does not provide the required surface quality. Conclusions. To improve the road paving quality using cold bitumen concrete mixes is necessary to heat the base before laying the cold mix. The heating temperature of the base depends on the layer thickness and ambient temperature.

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Spruit, Rodriaan, Frits van Tol, Wout Broere, Pieter Doornenbal, and Victor Hopman. "Distributed temperature sensing applied during diaphragm wall construction." Canadian Geotechnical Journal 54, no. 2 (February 2017): 219–33. http://dx.doi.org/10.1139/cgj-2014-0522.

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Distributed temperature sensing (DTS) can be used to monitor the production process of diaphragm walls. DTS is able to differentiate between already present or fresh bentonite suspensions during refreshing of the bentonite slurry in the trench. During concrete casting, DTS is able to differentiate between the bentonite suspension and concrete. As a result, the continuity of the casting process and the arrival of good grade concrete at crucial locations in the trench can be monitored. Tests conducted on laboratory models provided reference information for interpretation of field data. Field experiences have shown the benefits of DTS tests and the predictive value of the reference measurements. Results are compared with crosshole sonic logging measurements at the same location.

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36

Dahal, Sunita, and Rajan Suwal. "Seismic Behavior Analysis of Composite Buildings with Respect to RCC Buildings." Journal of the Institute of Engineering 15, no. 1 (January 31, 2019): 54–61. http://dx.doi.org/10.3126/jie.v15i1.27705.

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Steel concrete composite construction has gained wide acceptance worldwide as an alternative to pure steel and pure concrete construction. The use of steel in construction industry is very low in Nepal compared to many developing countries. There is a great potential for increasing the volume of steel in construction, especially in the current development needs. Not using steel as an alternative construction material and not using it where it is economical is a heavy loss for the country. Use of composite material is of particular interest, due to its significant potential in improving the overall performance through rather modest changes in manufacturing and constructional technologies. Steel concrete composite construction means the concrete slab is connected to the composite beam with the help of shear connectors so that they act as a single unit. In the present work, steel concrete composite (both full and half composite) with RCC options are considered for comparative study of seismic behavior of 10 multistoried commercial buildings (4-storied, 5-storied, 6-storied, 7-storied, 8-storied, 9-storied, 10-storied, 12-storied, 16-storied and 20-storied which is situated in earthquake zone V and for earthquake loading, the provisions of IS:1893 (Part1)-2002 is considered. For modeling of composite and RCC structures, SAP2000 software is used. Steel-concrete composite construction system is an efficient, economical and innovative method for seismic resistance of multi storied buildings. Equivalent static method of seismic analysis is used in the analysis of models. Comparison of parameters like time period, axial force, shear force, bending moment, deflection, storey drifts, base shear, storey stiffness is done for full composite (beam-column both composite), half composite (column composite) and RCC structures. The results are compared and found that composite structure is better in several aspects.

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37

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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38

Gao, Ming Zhou, Ji Hua Li, Ru Deng Luo, and Hai Long Wang. "Theoretical Calculation and Experimental Research of Shrinkage of High Strength Concrete an High-Speed Railway Bridges." Advanced Materials Research 1079-1080 (December 2014): 312–17. http://dx.doi.org/10.4028/www.scientific.net/amr.1079-1080.312.

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Concrete bridges on high-speed railway are usually constructed with high strength concrete. Because of shrinkage of concrete, large stress and deformation always appear in construction and operation process of bridges. It even leads to concrete cracking. So as to guarantee the safety of structures and smoothness of tracks, correct calculation of concrete shrinkage effect must be done. Concrete shrinkage effect is a very complex non-stress strain problem which is influenced by numerous factors and difficult to calculate. According to the factors considered from different emphasis aspects, a variety of patterns or specifications are formed based on different domestic and foreign models of concrete shrinkage calculation. Combined with the construction of Jiangshan Harbor Bridge (75+2×135+75) m prestressed concrete continuous beam bridge on Hangzhou-Changsha high-speed railway, concrete shrinkage field tests and measurements were carried in which the same mix of high strength concrete as that of the bridge was used. The results of tests and measurements were compared with results of different theoretical models. The effects of high strength concrete shrinkage on high-speed railway concrete bridges were studied and some useful conclusions were obtained.

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39

Yazdani, Nur, Bryant McKinnie, and Saif Haroon. "Aggregate-Based Modulus of Elasticity for Florida Concrete." Transportation Research Record: Journal of the Transportation Research Board 1914, no. 1 (January 2005): 15–23. http://dx.doi.org/10.1177/0361198105191400103.

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The current empirical model for the Florida Department of Transportation (FDOT) concrete modulus of elasticity (E) is a function of concrete compressive strength and unit weight. Recent testing shows that this model consistently underestimates E for FDOT concrete. This underestimation may lead to construction problems caused by the overprediction of camber and the deflection of concrete structural members. E values for the typical concrete mix used in FDOT projects were experimentally determined at various concrete ages. Regression analyses were used to find the E models that best fit the generated data, and such models were compared with existing E models from the literature. It was found that the aggregate type and specific gravity play significant roles in influencing the E value of concrete. The best-fit E models for FDOT concrete, together with suggested modification factors for various aggregate types, are recommended.

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40

Rubin, Oleg D., Sergey E. Lisichkin, and Oksana V. Zyuzina. "Experimental studies of the stress-strain state of reinforced concrete structures strengthened by prestressed basalt-composite rebar." Structural Mechanics of Engineering Constructions and Buildings 17, no. 3 (October 24, 2021): 288–98. http://dx.doi.org/10.22363/1815-5235-2021-17-3-288-298.

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Relevance. In recent years, composite materials have become widespread in the construction of reinforced concrete structures for industrial, civil and transport structures. It is proposed to strengthen the reinforced concrete structures of hydraulic structures with prestressed basalt composite rebar. It took an experimental and theoretical substantiation of technical solutions to strengthen the reinforced concrete structures of hydraulic structures with prestressed basalt composite reinforcement. The aim of the work was to carry out a set of experimental and theoretical studies of the stress-strain state and internal forces in low-reinforced concrete structures of hydraulic structures reinforced with prestressed basalt composite rebar. Methods. Experimental studies of the stress-strain state and internal forces were carried out on the basis of low-reinforced concrete beam-type models with interblock construction joints, harden with prestressed basalt composite reinforcement in the stretched (compressed) zones of the models. Theoretical studies of the stress-strain state and internal forces were carried out on the basis of the theory of reinforced concrete and structural mechanics. Results. As a result of the research carried out on typical low-reinforced concrete structures of hydraulic structures with interblock construction joints, the main stages of the stress-strain state of hydraulic reinforced concrete structures were formulated. Based on the data of experimental and theoretical studies, taking into account the reinforcement with prestressed basalt composite rebar, as well as with prestressed clamps in the shear zone, a method was developed for calculating the strength of low-reinforced hydrotechnical reinforced concrete structures with interblock construction joints.

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41

Tang, Xian Xi, Xian Zhou Tang, Yue Xu, and Wei Guo. "Analysis of the Reasonable Construction Size of Concrete Bridge Deck." Applied Mechanics and Materials 90-93 (September 2011): 1027–32. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.1027.

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In order to study the reasonable thickness and width of bridge decks of concrete T beam bridge, 36 ANSYS finite element models of simply supported concrete T beam were established, stress performance of each models have been analyzed under the centre load. The analysis results indicated that when the bridge deck thickness reached 22cm, it was no much sense of influence of bridge decks stress and deflection change by increasing the thickness of the bridge deck, therefore, the recommended value of deck thickness was about 22cm. Since the width of the bridge deck has little effect of the mechanical properties and stiffness of it, so the recommended values of the bridge decks width should be determined combined with the diaphragm and the integral stiffness of T beam bridge.

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42

Belsky, Michael, Charles Eastman, Rafael Sacks, Manu Venugopal, Shiva Aram, and Donghoon Yang. "Interoperability for precast concrete building models." PCI Journal 59, no. 2 (March 1, 2014): 144–55. http://dx.doi.org/10.15554/pcij.03012014.144.155.

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43

Shi, Xiaona, Xian Rong, Lin Nan, Lida Wang, and Jianxin Zhang. "A New Steel-Joint Precast Concrete Frame Structure: The Design, Key Construction Techniques, and Building Energy Efficiency." Buildings 12, no. 11 (November 14, 2022): 1974. http://dx.doi.org/10.3390/buildings12111974.

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Assembled methods play a critical role in the construction of precast concrete structures. However, conventional dry-connections-like sleeve grouting joints in precast concrete structures lagged at a low construction and management efficiency with poor quality control. In this study, a novel steel joint for precast reinforced concrete beam-column components is proposed to improve constructability. New joints transform the assembled method from reinforced concrete members into a steel structure by setting a pre-embedded steel connector at both ends of reinforced concrete beams and columns, showing outstanding economic, durability, and fire resistance capabilities. The construction process, construction efficiency, economy, and energy consumption were discussed based on the material, structure, and construction hybrid characteristics. Numerical simulation and structural health monitoring methods are used to monitor and evaluate the deformation and stress state of the proposed system in the whole construction process, so as to optimize the construction scheme and ensure safe and orderly construction. The results reveal that the FEA-simulated values of key building components during construction are in good agreement with the actual monitoring values, which verifies the feasibility of the FEM models and provides a guarantee for construction safety; the construction period of the proposed assemble system is reduced by approximately 56% and 40%, compared with the conventional reinforced concrete frame structure and cast-in-place joints in the precast concrete frame structure, respectively. Meanwhile, the energy consumption of buildings decreases by 20%. This research provides a theoretical basis for the design, calculation, and application of assembled precast structural systems.

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44

Jung, Jong-Suk, Emmanuel B. Owusu-Antwi, and Ji-Hwan An. "Analytical procedures for evaluating factors that affect joint faulting for jointed plain concrete pavements using the Long-Term Pavement Performance database." Canadian Journal of Civil Engineering 33, no. 10 (October 1, 2006): 1279–86. http://dx.doi.org/10.1139/l06-072.

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The objective of this study was to identify and quantify design and construction features most important to joint faulting of joint plain concrete pavements. With data obtained from the Long-Term Pavement Performance (LTPP) database, an analysis approach that combined pavement engineering expertise and modern data analysis techniques was to develop guidelines for improved design and construction of Portland cement concrete (PCC) pavement. The approach included typical preliminary analyses, but emphasis was placed on using a series of multivariate data analysis techniques. Discriminant analysis was used to develop models that classify individual pavement into performance groups developed by cluster analysis, which was used to partition the pavements into three distinct groups representing good, normal, and poor performance. These models can be used to classify and evaluate additional or new pavements performance throughout the pavement's design life. To quantify the levels of the key design and construction features that contribute to performance, the classification and regression tree procedure was used to develop tree-based models for performance measure. The analysis approach described was used to develop the guideline on the key design and construction features that can be used by designers to decrease joint faulting of jointed plain concrete pavements (JPCPs).Key words: faulting, Long-Term Pavement Performance (LTPP), jointed plain concrete pavement (JPCP), cluster analysis, discriminant analysis, classification and regression tree (CART) analysis.

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45

Yang, Zhao, Xiao Yu, and Yang Zhi Zhong. "Influence of Concrete Strength of the Core of the Joints on the Holistic Resistant Behavior of Super High-Rise Structure." Applied Mechanics and Materials 351-352 (August 2013): 396–400. http://dx.doi.org/10.4028/www.scientific.net/amm.351-352.396.

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In the construction process of the super high-rise concrete structure, it’s easy to be happened that the concrete strength of joints can’t meet design requirements. Some finite element models of a super high-rise building were established by MIDAS in the paper, which were used to analyze the influence of concrete strength of the core of the joints on the holistic resistant behavior. The study may provide the basis for solving the construction quality problems of the core area of joints

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46

Yuan, Xue Xia, and Wei Liang Jin. "Structural Reliability and Human Error of Reinforced-Concrete Building during Construction." Advanced Materials Research 368-373 (October 2011): 1365–69. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.1365.

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In view of the significant failure modes of formwork-supporting system and reinforced- concrete member, the reliability analysis model of time-dependent system affected by human errors during the construction of typical multistory reinforced-concrete buildings was developed. Human Reliability Analysis (HRA) method was applied to simulate the error rates and error magnitudes of the reinforced-concrete members and the formwork-supporting system, and human reliability models were developed, two cases for error-free case and error-included case were considered. Furthermore the check emphasis of formwork-supporting system was pointed during multistory building construction.

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47

Wang, Zheng Jun, Qiang Wang, Chun Hua Liu, Kun Hu, and Dian Hong Zhang. "Technique Research on Strength Estimation of Pile Foundation Based of Model Analysis." Advanced Materials Research 163-167 (December 2010): 2727–30. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.2727.

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In order to realize non-destructive testing of concrete strength of pouring stakes at the construction stages, the paper establishes two kinds of mathematics models between the concrete strength and the sound-speed through experiment on concrete test squares, model stakes and engineering piles ─ all of differently designed strength with method of ultrasonic. The concrete average strengths of the pouring piles were reckoned through engineering piles of practical testing and the errors were within the allowable range. So the validity of mathematics models was proved.

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48

Ivanov, L. A., L. D. Xu, E. S. Bokova, A. D. Ishkov, and S. R. Muminova. "Nanotechnologies: a review of inventions and utility models. Part V." Nanotechnologies in Construction A Scientific Internet-Journal 12, no. 6 (December 27, 2020): 331–38. http://dx.doi.org/10.15828/2075-8545-2020-12-6-331-338.

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The article provides an abstract review of patents. The results of creative activity of scientists, engineers and specialists, including inventions in the field of nanotechnology and nanomaterials, being implemented, allow achieving a significant effect in construction, housing and community services, and related sectors of the economy. For example, the invention «A method to produce dry construction mixtures» refers to manufacturing of building materials, in particularly, to manufacture of dry construction mixtures (DCM) by the method of joint mechanoactivation of cement and dolomite, with further modification of them with carbon nanostructures (CNT). The technical result of the given method of mixing CNT and main component of dry construction mixtures - cement – is that it makes possible to use microquantities (0.005%) of CNT in DCM. That allows decreasing product cost of obtained mixture. Moreover, due to increased strength, faster hardening of materials one can reduce consumption of these mixtures. That is additional factor affecting decrease of mixture product cost. The results obtained after application of mechanoactivation of basic mixture components were different practically by all indicators from the mixtures prepared by simple mixing. Compression strength and tensile strength increased by 10–15%, adhesion strength increased too. Along with increasing of strength characteristics such an important indicator of DCM as air permeability has decreased. Reduction of total volume of pores in dense structure of cement matrix caused dramatic slow-up of moisture diffusion rate. The specialists can also be interested in the following inventions in the area of nanotechnologies: a method of laser building-up welding for metal coatings, high RAP in WMA surface mixture containing nanoglass fibers, a device to apply nanoparticles of metal oxides on metal surface under normal conditions, multifunctional nanostructured additive for coatings, experimental assessment of cement mortar using nanooxide compounds, a composition for setting constructional layers of road pavements, a method to obtain composite films of nanofibers, nano-engineering of construction materials using molecular dynamics simulations, cast and self-compacting concrete mixture for cast-in-situ concrete and prefabricated reinforced units, a method to obtain photocatalyst based on nanotubular titanium dioxide et al

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Wu, Xiangping, Fei Zhu, Mengmeng Zhou, Mohanad Muayad Sabri Sabri, and Jiandong Huang. "Intelligent Design of Construction Materials: A Comparative Study of AI Approaches for Predicting the Strength of Concrete with Blast Furnace Slag." Materials 15, no. 13 (June 29, 2022): 4582. http://dx.doi.org/10.3390/ma15134582.

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Concrete production by replacing cement with green materials has been conducted in recent years considering the strategy of sustainable development. This study researched the topic of compressive strength regarding one type of green concrete containing blast furnace slag. Although some researchers have proposed using machine learning models to predict the compressive strength of concrete, few researchers have compared the prediction accuracy of different machine learning models on the compressive strength of concrete. Firstly, the hyperparameters of BP neural network (BPNN), support vector machine (SVM), decision tree (DT), random forest (RF), K-nearest neighbor algorithm (KNN), logistic regression (LR), and multiple linear regression (MLR) are tuned by the beetle antennae search algorithm (BAS). Then, the prediction effects of the above seven machine learning models on the compressive strength of concrete are evaluated and compared. The comparison results show that KNN has higher R values and lower RSME values both in the training set and test set; that is, KNN is the best model for predicting the compressive strength of concrete among the seven machine learning models mentioned above.

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Kumar, Aman, Harish Chandra Arora, Nishant Raj Kapoor, Mazin Abed Mohammed, Krishna Kumar, Arnab Majumdar, and Orawit Thinnukool. "Compressive Strength Prediction of Lightweight Concrete: Machine Learning Models." Sustainability 14, no. 4 (February 19, 2022): 2404. http://dx.doi.org/10.3390/su14042404.

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Concrete is the most commonly used construction material. The physical properties of concrete vary with the type of concrete, such as high and ultra-high-strength concrete, fibre-reinforced concrete, polymer-modified concrete, and lightweight concrete. The precise prediction of the properties of concrete is a problem due to the design code, which typically requires specific characteristics. The emergence of a new category of technology has motivated researchers to develop mechanical strength prediction models using Artificial Intelligence (AI). Empirical and statistical models have been extensively used. These models require a huge amount of laboratory data and still provide inaccurate results. Sometimes, these models cannot predict the properties of concrete due to complexity in the concrete mix design and curing conditions. To conquer such issues, AI models have been introduced as another approach for predicting the compressive strength and other properties of concrete. This article discusses machine learning algorithms, such as Gaussian Progress Regression (GPR), Support Vector Machine Regression (SVMR), Ensemble Learning (EL), and optimized GPR, SVMR, and EL, to predict the compressive strength of Lightweight Concrete (LWC). The simulation approaches of these trained models indicate that AI can provide accurate prediction models without undertaking extensive laboratory trials. Each model’s applicability and performance were rigorously reviewed and assessed. The findings revealed that the optimized GPR model (R = 0.9803) used in this study had the greatest accuracy. In addition, the optimized SVMR and GPR model showed good performance, with R-values 0.9777 and 0.9740, respectively. The proposed model is economic and efficient, and can be adopted by researchers and engineers to predict the compressive strength of LWC.

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