OPTIMAL CONSTRUCTION AND TECHNOLOGICAL SOLUTION FOR RECONSTRUCTION OF A CITY PIPELINE AND THE RESULTS OF ITS TESTS

Purpose. To once again draw the attention of bridge owners and bridge experts to the problems of reconstruction of long-term bridges and on a concrete example of reconstruction of a rather problematic city overpass operated for more than 60 years to shows that with the optimal structural and technological solutions of the reconstruction received a restored bridge, and its operational and technical and economic indicators which according to the requirements of the National Building Norms completely correspond to the new bridge, but the reconstruction cost and the lead time are greatly reduced. Methodology. To achieve this purpose over the past ten years of operation of the overpass conducted three inspections and full-scale static tests. It is determined that most of the existing reinforced concrete structures, although defective and in need of repair, can be used for further operation after reconstruction, provided they are reinforced. Worn out non-repairable structures that needed to be replaced were also found. Results. According to these initial data, a reconstruction project was developed using scientific and technological structure developments of the Branch Research Laboratory 88 of Lviv Polytechnic National University for the reconstruction of bridges. The span structure has been expanded to 4 lanes from the size G-10.5 + 2 × 0.9 m to the new G-16.5 + 2 × 1.5 m in a combined way – symmetrical completion of two new beams with their support on the extended support and installation of a reinforced concrete extension board with cantilever overhangs 2.7 m long. The most damaged boundary beams were replaced with new ones, designed for normalized temporary loads A15 and NK-100. For further operation the other existing beams are reinforced in one of the least expensive ways – by changing the static scheme from the existing split to the new clamped on the supports frame-inseparable. A set of repair works is provided to ensure the normalized durability of the reconstructed overpass. The scientific novelty is to develop a method for determining the experimental Coefficients of Transverse Distribution of Bending Moments (CTDM) and external loads (CTD) based on the results of tests of the span structure. The possibility of applying the method of elastic supports for the spatial calculation of span structures with beams of different stiffness is confirmed. Practical significance. The use of optimal design solutions for the reconstruction of existing span structures: reinforced concrete billboard with large cantilever overhangs to expand and change the static scheme to strengthen the beams of span structures.

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Improvement Of Curvilinear Diagrams Of Concrete Deformation

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.08.99-104 ◽

2019 ◽

pp. 99-104

Keyword(s):

Reinforced Concrete ◽

Peak Load ◽

Experimental Studies ◽

Concrete Structures ◽

Deformation Model ◽

Reinforced Concrete Structures ◽

Significant Difference ◽

Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

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Physical Nonlinear Model Adaptation in Long-Term Structural Health Monitoring: Proposals of Experimental Studies on a Reinforced Concrete Beam

IABSE Symposium Report ◽

10.2749/222137810796063562 ◽

2010 ◽

Vol 97 (8) ◽

pp. 32-38

Author(s):

Martina Schnellenbach-Held ◽

Bjoern Karczewski

Keyword(s):

Reinforced Concrete ◽

Structural Health Monitoring ◽

Nonlinear Model ◽

Health Monitoring ◽

Concrete Beam ◽

Experimental Studies ◽

Reinforced Concrete Beam ◽

Model Adaptation ◽

Structural Health

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Research on the Economic Vitality of the Northeast China

Journal of Economic Science Research ◽

10.30564/jesr.v3i3.1829 ◽

2020 ◽

Vol 3 (3) ◽

Author(s):

Jiayue Jiao

Keyword(s):

Northeast China ◽

Practical Significance ◽

Economic Policies ◽

Regional Competitiveness ◽

Regional Economic ◽

Important Indicator ◽

Depth Study ◽

Long Term Impact ◽

Economic Vitality

Economic vitality is an important indicator of regional competitiveness. The demand for talents and the vitality of enterprises in different regions are obvious to all and have practical significance. Therefore, it is necessary to establish a survey data model and conduct in-depth study on improving regional economic vitality from the perspective of policy.Based on a variety of forecasting methods, this paper analyzes the short-term and long-term impact of economic policies in Northeast China, and finally puts forward the factors that affect the economic vitality of northeast policies. Finally, the paper puts forward the feasibility and targeted suggestions of strengthening regional economic vitality, obtaining long-term development and building a more competitive city in the new era.

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MEDIA AND INFORMATION LITERACY: THE SOLUTION OF QUESTIONS OF FORMATION OF A CIVIC STAND IN

UKRAINIAN ASSEMBLY OF DOCTORS OF SCIENCES IN PUBLIC ADMINISTRATION ◽

10.31618/vadnd.v1i13.129 ◽

2018 ◽

Vol 1 (13) ◽

pp. 14-27

Author(s):

Laila Seysembekovna Akhmetova ◽

Dmitry Pavlovich Shorokhov

Keyword(s):

Information Literacy ◽

Modern Society ◽

International Standards ◽

Media Education ◽

Practical Significance ◽

Sociological Research ◽

Conceptual Approach ◽

Target Groups ◽

National University ◽

Psychology Pedagogy

For the world community UNESCO has developed international standards of media information literacy, which have been adopted by all UNESCO member countries. In Central Asia, Kazakhstan was the first to deal with these issues 10 years ago. The group of scientists of the Kazakh National University named by al-Farabi is working on studying this issue. Most of the scientific works on media education are aimed at justifying the need for media education in modern society and its value. The purpose of the article is the development of methodological materials on the formation of literacy in the field of media and information literacy for training target groups and informing the public. The authors of this article apply the methodology of comparative historical research, the methodology and technique of sociological research, the systemic and structural-functional approach in combination with comparative historical method and statistical data analysis, as well as the study of official documents characterizing the policy of international community and Kazakhstan. Also, content analysis and qualitative documents analysis, as well as comparative research methods, were used. As a result of the research, it was concluded that any conceptual design, scientific paradigm suffers to some extent with idealization and the conceptual approach of UNESCO discussion formed the basis for this review, causing positive expectations. However, media is not always socially-oriented tool. It is clear that in this scenario, it is not necessary to rely solely on the consciousness of journalists and self-censorship of editors. However, understanding the principal approaches of UNESCO and following the recommendations developed can control risks and contribute to the development of a full-fledged civil society. Practical significance of the research lies in the possibility of using its results in the field of media, psychology, pedagogy, culture, history, journalists, political scientists, social engineers, teachers, students and post-graduate students of universities. The results of the research can be integrated into the educational and upbringing processes. It is necessary to train target groups for the further dissemination and training of media and information literacy and to address the issues of forming a civic position in Kazakhstan.

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Long-Term Concrete Shrinkage Influence on the Performance of Reinforced Concrete Structures

Materials ◽

10.3390/ma14020254 ◽

2021 ◽

Vol 14 (2) ◽

pp. 254

Author(s):

Alinda Dey ◽

Akshay Vijay Vastrad ◽

Mattia Francesco Bado ◽

Aleksandr Sokolov ◽

Gintaris Kaklauskas

Keyword(s):

Reinforced Concrete ◽

Reinforced Concrete Structures ◽

Tension Stiffening ◽

Model Code ◽

Concrete Shrinkage ◽

Time Period ◽

Governing Factor ◽

Model Code 2010 ◽

Mathematical Process

The contribution of concrete to the tensile stiffness (tension stiffening) of a reinforced concrete (RC) member is a key governing factor for structural serviceability analyses. However, among the current tension stiffening models, few consider the effect brought forth by concrete shrinkage, and none studies take account of the effect for very long-term shrinkage. The present work intends to tackle this exact issue by testing multiple RC tensile elements (with different bar diameters and reinforcement ratios) after a five-year shrinking time period. The experimental deformative and tension stiffening responses were subjected to a mathematical process of shrinkage removal aimed at assessing its effect on the former. The results showed shrinkage distinctly lowered the cracking load of the RC members and caused an apparent tension stiffening reduction. Furthermore, both of these effects were exacerbated in the members with higher reinforcement ratios. The experimental and shrinkage-free behaviors of the RC elements were finally compared to the values predicted by the CEB-fib Model Code 2010 and the Euro Code 2. Interestingly, as a consequence of the long-term shrinkage, the codes expressed a smaller relative error when compared to the shrinkage-free curves versus the experimental ones.

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An Assessment of the Long-Term Durability of Concrete in Radioactive Waste Repositories

MRS Proceedings ◽

10.1557/proc-50-239 ◽

1985 ◽

Vol 50 ◽

Cited By ~ 16

Author(s):

A. Atkinson ◽

D. J. Goult ◽

J. A. Hearne

Keyword(s):

Reinforced Concrete ◽

Radioactive Waste ◽

Concrete Slab ◽

Laboratory Studies ◽

Preliminary Assessment ◽

Reinforced Concrete Slab ◽

Radioactive Waste Repositories ◽

Waste Repositories ◽

Durability Of Concrete

AbstractA preliminary assessment of the long-term durability of concrete in a repository sited in clay is presented. The assessment is based on recorded experience of concrete structures and both field and laboratory studies. It is also supported by results of the examination of a concrete sample which had been buried in clay for 43 years.The enoineering lifetime of a 1 m thick reinforced concrete slab, with one face in contact with clay, and the way in which pH in the repository as a whole is likely to vary with time have both been estimated from available data. The estimates indicate that engineering lifetimes of about 103 years are expected (providing that sulphate resisting cement is used) and that pH is likely to remain above 10.5 for about 106 years.

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Effect of material properties on long-term deflections of GFRP reinforced concrete beams

Construction and Building Materials ◽

10.1016/j.conbuildmat.2012.11.055 ◽

2013 ◽

Vol 41 ◽

pp. 99-108 ◽

Cited By ~ 23

Author(s):

C. Miàs ◽

Ll Torres ◽

A. Turon ◽

I.A. Sharaky

Keyword(s):

Reinforced Concrete ◽

Material Properties ◽

Concrete Beams ◽

Reinforced Concrete Beams

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Long-Term Deformations of Strengthened Reinforced Concrete Linear Elements

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.691.51 ◽

2016 ◽

Vol 691 ◽

pp. 51-60 ◽

Cited By ~ 1

Author(s):

Martin Krizma ◽

Lubomir Bolha

Keyword(s):

Reinforced Concrete ◽

Long Term Results ◽

Short Term ◽

Limit States ◽

Linear Elements ◽

Repeated Load ◽

The Moment ◽

Concrete Elements ◽

Fiber Fabric

The issue of strengthening the damaged linear reinforced concrete elements have been engaged since 2008. We focused on the analysis of resistance and the characteristics of limit states of serviceability in the damaged and subsequently strengthened elements at a short-term loading. In the introduction phase, the strengthening of the elements was carried out with the following procedures – installation of an overlayer on the coupling board or a combination of the board and use of glass – fiber fabric (GFRP). The strengthening was also affected by the type of contact (reinforced/non-reinforced) – the deformed element/coupling board and its effect on resistance, type of deformation and serviceability. In the non-reinforced contact, we applied some of the types of adjustments to the surface of the strengthened element. At the moment, we are dealing with the effects of time and repeated load on the strengthened elements. The results correspond to the reinforced contact. The values are compared with the short-term results of the strengthened beams and with the long-term results of the beams prepared for strengthening.

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