Linear expressions for tension stiffening of concrete are nowadays widely used in software packages of structural analysis. Nevertheless, more elaborated expressions of tension stiffening available in the literature have been used successfully in the past. The use of linear approximations is justified since the influence of the tension stiffening effect in the deformation of the structure is small but not negligible. In this sense, linear approximations are simpler and can be accurate enough. However, this linear approximation, in its present form, does not provide good results in terms of deformations at the element level. This paper proposes a linear expression of the tension stiffening supported by the experimental formulation used to predict the flexural behavior of concrete beams. A detailed example is presented.
{"title":"Linear Concrete Tension Stiffening Model for Reinforced Concrete Elements","authors":"Luisa María Hernández-Gil, E. Hernández-Montes","doi":"10.33586/hya.2023.3097","DOIUrl":"https://doi.org/10.33586/hya.2023.3097","url":null,"abstract":"Linear expressions for tension stiffening of concrete are nowadays widely used in software packages of structural analysis. Nevertheless, more elaborated expressions of tension stiffening available in the literature have been used successfully in the past. The use of linear approximations is justified since the influence of the tension stiffening effect in the deformation of the structure is small but not negligible. In this sense, linear approximations are simpler and can be accurate enough. However, this linear approximation, in its present form, does not provide good results in terms of deformations at the element level. This paper proposes a linear expression of the tension stiffening supported by the experimental formulation used to predict the flexural behavior of concrete beams. A detailed example is presented.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41566285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The second generation of the Structural Eurocodes is expected to be published by 2026. This article describes design provisions for laps and anchorages of normal ribbed reinforcement in Sections 11.4 and 11.5 of the final draft of the forthcoming version of Eurocode 2, the European Code for Design of Concrete Structures. This article outlines why and how design provisions have been modified, demonstrates the physical rationale for the rules and notes the evidence on which the justification is based. It also indicates the impact of the revisions. The article gives an overview of the factors influencing anchorage and lap strength and presents a historic perspective on the development of the revised rules. The influence of each factor as represented in current and revised are then compared. The revised rules are then validated against test databases for anchorages and for tension and compression laps, and the impact of the revisions on design practice for selected situations are briefly examined.
{"title":"Design Provisions for Anchorages and Laps in the Revised EC2","authors":"J. Cairns","doi":"10.33586/hya.2023.3118","DOIUrl":"https://doi.org/10.33586/hya.2023.3118","url":null,"abstract":"The second generation of the Structural Eurocodes is expected to be published by 2026. This article describes design provisions for laps and anchorages of normal ribbed reinforcement in Sections 11.4 and 11.5 of the final draft of the forthcoming version of Eurocode 2, the European Code for Design of Concrete Structures. This article outlines why and how design provisions have been modified, demonstrates the physical rationale for the rules and notes the evidence on which the justification is based. It also indicates the impact of the revisions. \u0000The article gives an overview of the factors influencing anchorage and lap strength and presents a historic perspective on the development of the revised rules. The influence of each factor as represented in current and revised are then compared. The revised rules are then validated against test databases for anchorages and for tension and compression laps, and the impact of the revisions on design practice for selected situations are briefly examined.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45286401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a summary of the procedures for elaborating the Eurocodes that started in the last two decades of the 20th century with some emphasis in the Eurocode 2 on concrete structures. Besides, a general scope of the technical content of new proposal for Eurocode 2 is commented and the main changes are highlighted.
{"title":"The Origins and Some Highlights on the New Proposal for Eurocode 2","authors":"José María Arrieta, Jesús Rodríguez, H. Ganz","doi":"10.33586/hya.2023.3115","DOIUrl":"https://doi.org/10.33586/hya.2023.3115","url":null,"abstract":"This paper presents a summary of the procedures for elaborating the Eurocodes that started in the last two decades of the 20th century with some emphasis in the Eurocode 2 on concrete structures. Besides, a general scope of the technical content of new proposal for Eurocode 2 is commented and the main changes are highlighted.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41618229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Miguel, M. Fernández, J. Hegger, Maximilian Schmidt
The second generation of Eurocode 2 incorporates formulations based on physical models which are general enough for the assessment of existing structures but can be simplified for the design of new structures, in order to improve the ease-of-use. One of the areas where these improvements are addressed is the shear verification of members without shear reinforcement, such as solid slabs, walls, cut-and-cover tunnels, precast ribs or hollow core slabs, which in some cases are prestressed or subjected to external axial loading.In current Eurocode 2, the shear verification of these structures is based on an empirical formulation proposed by Zsutty in 1968. The final draft of the new version of Eurocode 2 has adopted the Critical Shear Crack Theory (CSCT) as the theoretical basis for the formulation of the shear resistance, which allows a better understanding of structural behaviour in many different conditions, not only for the design of new structures, but also for the assessment of existing structures. This formulation accounts for some aspects that are not well considered in current Eurocode 2, which have been underlined as shortcomings in recent years.The formulation for design of new structures in the final draft of the new version of Eurocode 2 (General Model) is easy to use for the verification of the shear resistance, but requires an iterative process to calculate the shear capacity of sections in the presence of axial forces. For this reason, the final draft of the new version of Eurocode 2 also provides an alternative non-iterative formulation (Linear Approach) to calculate the shear capacity in presence of compressive axial forces, based on the linearisation of the CSCT shear failure criterion and formulated with the same additive structure as in the current Eurocode 2, useful for the most common cases.This paper presents the General Model formulation provided in the next Eurocode 2 for the shear verification of axially loaded members without shear reinforcement, as well as the alternative formulation (linear approach). In addition, the agreement of both formulations with experimental results from an available shear test database on prestressed concrete beams is shown and the consistency of the safety treatment between the two formulations is also discussed.
{"title":"Shear Resistance of Members Without Shear Reinforcement in Presence of Axial Forces in the Next Eurocode 2","authors":"P. Miguel, M. Fernández, J. Hegger, Maximilian Schmidt","doi":"10.33586/hya.2023.3112","DOIUrl":"https://doi.org/10.33586/hya.2023.3112","url":null,"abstract":"The second generation of Eurocode 2 incorporates formulations based on physical models which are general enough for the assessment of existing structures but can be simplified for the design of new structures, in order to improve the ease-of-use. One of the areas where these improvements are addressed is the shear verification of members without shear reinforcement, such as solid slabs, walls, cut-and-cover tunnels, precast ribs or hollow core slabs, which in some cases are prestressed or subjected to external axial loading.In current Eurocode 2, the shear verification of these structures is based on an empirical formulation proposed by Zsutty in 1968. The final draft of the new version of Eurocode 2 has adopted the Critical Shear Crack Theory (CSCT) as the theoretical basis for the formulation of the shear resistance, which allows a better understanding of structural behaviour in many different conditions, not only for the design of new structures, but also for the assessment of existing structures. This formulation accounts for some aspects that are not well considered in current Eurocode 2, which have been underlined as shortcomings in recent years.The formulation for design of new structures in the final draft of the new version of Eurocode 2 (General Model) is easy to use for the verification of the shear resistance, but requires an iterative process to calculate the shear capacity of sections in the presence of axial forces. For this reason, the final draft of the new version of Eurocode 2 also provides an alternative non-iterative formulation (Linear Approach) to calculate the shear capacity in presence of compressive axial forces, based on the linearisation of the CSCT shear failure criterion and formulated with the same additive structure as in the current Eurocode 2, useful for the most common cases.This paper presents the General Model formulation provided in the next Eurocode 2 for the shear verification of axially loaded members without shear reinforcement, as well as the alternative formulation (linear approach). In addition, the agreement of both formulations with experimental results from an available shear test database on prestressed concrete beams is shown and the consistency of the safety treatment between the two formulations is also discussed.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45548294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper the main changes introduced into FprEN 1992-1-1:2022 with respect to the current version of EC2 (EN 1992-1-1:2004) with regard to cracking and deflection calculations areintroduced and justified. The changes introduced into the cracking formulation account for the variation of stresses in the tensioned zones for bending, the effect of the casting position and the influence of curvature on the increase of surface crack widths. The introduction of these effects, together with a reformulation of the effective area allow for a reduction of scatter in the model when compared to experimental data. For deflections, a simplified method is introduced which is fully consistent with the general method and allows practical application by providing correction factors to be applied to linear elastic calculations. From this method a formulation for the slenderness limits is deduced. This formulation is the basis for the table-based method to avoid deflection calculations. Finally coefficients are derived to translate the slenderness limits of beams to the slenderness limits of slabs supported on isolated columns and slabs supported on walls.
{"title":"Serviceability Limit States according to the new Eurocode 2 proposal: Description and justifications of the proposed changes","authors":"A. Pérez, J. L. Bellod, L. Torres, T. Kanstad","doi":"10.33586/hya.2023.3104","DOIUrl":"https://doi.org/10.33586/hya.2023.3104","url":null,"abstract":"In this paper the main changes introduced into FprEN 1992-1-1:2022 with respect to the current version of EC2 (EN 1992-1-1:2004) with regard to cracking and deflection calculations areintroduced and justified. The changes introduced into the cracking formulation account for the variation of stresses in the tensioned zones for bending, the effect of the casting position and the influence of curvature on the increase of surface crack widths. The introduction of these effects, together with a reformulation of the effective area allow for a reduction of scatter in the model when compared to experimental data. For deflections, a simplified method is introduced which is fully consistent with the general method and allows practical application by providing correction factors to be applied to linear elastic calculations. From this method a formulation for the slenderness limits is deduced. This formulation is the basis for the table-based method to avoid deflection calculations. Finally coefficients are derived to translate the slenderness limits of beams to the slenderness limits of slabs supported on isolated columns and slabs supported on walls.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41500148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the design and assessment of precast concrete beams with a slab cast on top, namely concrete composite beams, engineers still face in practice unsolved shear-related issues, such as the contribution to shear strength of the slab, the concrete strength to be considered in shear formulations or the influence of the interface between concretes in the shear behaviour. In the present research, 69 shear tests were performed on monolithic and composite beams, with rectangular or T-shaped cross-section, with or without transverse reinforcement and with different concrete qualities, to experimentally analyse the issues mentioned above. The study of the shear transfer mechanisms at failure led to formulating a model for explaining the observed results. Based on this model, a shear strength predictive formulation for concrete composite beams with web reinforcement has been developed, which has been verified with the experimental results from this research and 24 additional tests from the literature. This formulation provides accurate predictions compared to the shear strength formulations of current codes EC2, MC-10 and ACI 318-19. The proposed model lays the foundations for the future development of a user-friendly formulation for calculating the shear strength of concrete composite beams.
{"title":"Towards the development of a formulation for obtaining the shear strength of concrete composite beams","authors":"Lisbel Rueda, J. Bonet, P. Miguel, M. Fernández","doi":"10.33586/hya.2023.3107","DOIUrl":"https://doi.org/10.33586/hya.2023.3107","url":null,"abstract":"In the design and assessment of precast concrete beams with a slab cast on top, namely concrete composite beams, engineers still face in practice unsolved shear-related issues, such as the contribution to shear strength of the slab, the concrete strength to be considered in shear formulations or the influence of the interface between concretes in the shear behaviour. In the present research, 69 shear tests were performed on monolithic and composite beams, with rectangular or T-shaped cross-section, with or without transverse reinforcement and with different concrete qualities, to experimentally analyse the issues mentioned above. The study of the shear transfer mechanisms at failure led to formulating a model for explaining the observed results. Based on this model, a shear strength predictive formulation for concrete composite beams with web reinforcement has been developed, which has been verified with the experimental results from this research and 24 additional tests from the literature. This formulation provides accurate predictions compared to the shear strength formulations of current codes EC2, MC-10 and ACI 318-19. The proposed model lays the foundations for the future development of a user-friendly formulation for calculating the shear strength of concrete composite beams.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43497267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eduardo Díaz-Pavón, Raúl Rodríguez, Jorge Ley, Pedro López
This article highlights the most relevant aspects of the new generation of Eurocodes for the assessment of existing structures, and in particular those governing concrete structures. In this respect, Eurocode 0 will include a new section (prEN 1990-2. Basis of assessment and retrofitting of existing structures: general rules and actions) covering the approach and analysis that must be included in this type of assessment, while Eurocode 2 (prEN1992-1-1:2021 Design of concrete structures) includes Annex I: Assessment of existing structures, which is informative and covers particular aspects of the assessment of concrete structures.
{"title":"Contributions of the Future Eurocode for the Assessment of Existing Concrete Structures","authors":"Eduardo Díaz-Pavón, Raúl Rodríguez, Jorge Ley, Pedro López","doi":"10.33586/hya.2023.3103","DOIUrl":"https://doi.org/10.33586/hya.2023.3103","url":null,"abstract":"This article highlights the most relevant aspects of the new generation of Eurocodes for the assessment of existing structures, and in particular those governing concrete structures. In this respect, Eurocode 0 will include a new section (prEN 1990-2. Basis of assessment and retrofitting of existing structures: general rules and actions) covering the approach and analysis that must be included in this type of assessment, while Eurocode 2 (prEN1992-1-1:2021 Design of concrete structures) includes Annex I: Assessment of existing structures, which is informative and covers particular aspects of the assessment of concrete structures.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48265907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
U. Kuhlmann, Christina Schmidt‐Rasche, Jennifer Spiegler, Fabian Jörg, Vahid Pourostad, M. Euler
This paper gives an overview on recent work regarding the revision of EN 1993 on European level including selected scientific and technical issues and a summary of the activities executed within the European Standardization committee CEN/TC250/SC3 “Design of Steel Structures“ under the chair of Prof. Dr.-Ing. Ulrike Kuhlmann. This includes the description of current normative developments for the 2nd Generation of Eurocodes which aim at an evolution by improvements and harmonisation of the existing codes. In addition, a technical review of selected rules is given on a number of issues, which support the code revision and reflect well the recent tendencies in steel structures.
{"title":"Development of Eurocode 3 and Research Contributions","authors":"U. Kuhlmann, Christina Schmidt‐Rasche, Jennifer Spiegler, Fabian Jörg, Vahid Pourostad, M. Euler","doi":"10.33586/hya.2022.3113","DOIUrl":"https://doi.org/10.33586/hya.2022.3113","url":null,"abstract":"This paper gives an overview on recent work regarding the revision of EN 1993 on European level including selected scientific and technical issues and a summary of the activities executed within the European Standardization committee CEN/TC250/SC3 “Design of Steel Structures“ under the chair of Prof. Dr.-Ing. Ulrike Kuhlmann. This includes the description of current normative developments for the 2nd Generation of Eurocodes which aim at an evolution by improvements and harmonisation of the existing codes. In addition, a technical review of selected rules is given on a number of issues, which support the code revision and reflect well the recent tendencies in steel structures.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46467431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Ruiz, Á. De La Rosa, E. Poveda, R. Zanon, M. Schäfer, S. Wolf
This paper describes the model for the compressive stress-strain behavior of steel fiber-reinforced concrete (SFRC) in Annex L of the new Eurocode 2 (version 2022-05, EC2), developed within CEN TC250/SC2/WG1/TG2 – Fiber reinforced concrete. The model uses functions obtained from correlations with an extensive database comprised of 197 well-documented SFRC compressive tests and 484 flexural tests. We detailedly explain the model and derive the strain values for the parabola-rectangle model for ULS of SFRC in Annex L. In addition, we also use the model and the correlations with the database to provide a link between the compressive and the flexural performance classes in EC2, which allows a complete definition of any particular SFRC. Likewise, we derive parabola-rectangle strain values for each flexural performance class, which is mainly advantageous for the stronger flexural classes. Finally, we give an example showing the enhancement in strength and ductility of a composite steel-SFRC section endorsed with the new model, which results of 15% and 100%, respectively.
{"title":"Compressive behavior of steel-fiber reinforced concrete in Annex L of new Eurocode 2","authors":"G. Ruiz, Á. De La Rosa, E. Poveda, R. Zanon, M. Schäfer, S. Wolf","doi":"10.33586/hya.2022.3092","DOIUrl":"https://doi.org/10.33586/hya.2022.3092","url":null,"abstract":"This paper describes the model for the compressive stress-strain behavior of steel fiber-reinforced concrete (SFRC) in Annex L of the new Eurocode 2 (version 2022-05, EC2), developed within CEN TC250/SC2/WG1/TG2 – Fiber reinforced concrete. The model uses functions obtained from correlations with an extensive database comprised of 197 well-documented SFRC compressive tests and 484 flexural tests. We detailedly explain the model and derive the strain values for the parabola-rectangle model for ULS of SFRC in Annex L. In addition, we also use the model and the correlations with the database to provide a link between the compressive and the flexural performance classes in EC2, which allows a complete definition of any particular SFRC. Likewise, we derive parabola-rectangle strain values for each flexural performance class, which is mainly advantageous for the stronger flexural classes. Finally, we give an example showing the enhancement in strength and ductility of a composite steel-SFRC section endorsed with the new model, which results of 15% and 100%, respectively.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48600308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The new version of Eurocode 2 will include for the first time an informative annex, Annex R “Embedded FRP reinforcement”, to design reinforced concrete structures with fibre reinforced polymer (FRP) reinforcement. FRP embedded reinforcement has some advantages such as their low susceptibility to corrosion, high‐strength, and low life‐cycle cost. FRP rebars can be used as longitudinal or transverse reinforcement in a similar way than conventional steel rebars, but considering some particular aspects, such as their linear elastic behaviour up to failure or their lower modulus of elasticity, which may condition the design by the verification of theserviceability limit state. Since, the content of Annex R is new, a summary and background related to all aspects required for designing with FRP reinforcement are given in this paper.
{"title":"Embedded Fibre Reinforced Polymers (FRP) in Concrete Structures According to the New Version of Eurocode 2","authors":"Eva Oller Ibars, L. Torres, A. de Diego","doi":"10.33586/hya.2022.3098","DOIUrl":"https://doi.org/10.33586/hya.2022.3098","url":null,"abstract":"The new version of Eurocode 2 will include for the first time an informative annex, Annex R “Embedded FRP reinforcement”, to design reinforced concrete structures with fibre reinforced polymer (FRP) reinforcement. FRP embedded reinforcement has some advantages such as their low susceptibility to corrosion, high‐strength, and low life‐cycle cost. FRP rebars can be used as longitudinal or transverse reinforcement in a similar way than conventional steel rebars, but considering some particular aspects, such as their linear elastic behaviour up to failure or their lower modulus of elasticity, which may condition the design by the verification of theserviceability limit state. Since, the content of Annex R is new, a summary and background related to all aspects required for designing with FRP reinforcement are given in this paper.","PeriodicalId":41423,"journal":{"name":"Hormigon y Acero","volume":" ","pages":""},"PeriodicalIF":0.1,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48196883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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