Monitoring of Concrete Durability and Application in Qingdao Bay Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 1205-1211
Author(s):  
Xin Peng Shao ◽  
Hui Ji ◽  
Bao Lin Guo ◽  
Zong Guang Sun ◽  
Jian Fei Mao
Keyword(s):  
Concrete Structure ◽  
Engineering Practice ◽  
Corrosion Mechanism ◽  
Corrosion Monitoring ◽  
Concrete Durability ◽  
Critical Data ◽  
The World ◽  
Key Factor ◽  
Main Factor ◽  
Durability Of Concrete

The life of concrete structure located in complex environment depends largely on the durability of concrete. The various environmental corrosive effects are the key factor to reduce the durability of concrete structures. The studies on corrosion mechanism and detecting/monitoring technology are carried out in the world, and achieved important results. Since the 90's of last century, corrosion monitoring system for concrete structure has been put into engineering practice in the world, and the technology has been being mature. Qingdao Bay Bridge is located in the special marine environment, so corrosion is the main factor affecting the durability of the bridge. Durability monitoring is one of important aspects of the structure health monitoring and maintenance management system of the Bay Bridge. By corrosion monitoring, the critical data of concrete durability and strength degradation of the structure can be obtained. It is very significant for understanding the evolvement law of the durability, developing anti-corrosion measures, and extending the life of the bridge.

Durability of Concrete Structure Research and Development Direction

2010 ◽  
Vol 44-47 ◽  
pp. 2346-2353
Author(s):  
Lei Jiang ◽  
Ji Tao Yao ◽  
Ren Xin ◽  
Wei Li
Keyword(s):  
Research And Development ◽  
Concrete Structure ◽  
International Research ◽  
Concrete Structures ◽  
Future Research ◽  
Development Direction ◽  
The World ◽  
Four Levels ◽  
Structure Research ◽  
Durability Of Concrete

Currently, durability of concrete structures is a hot area of civil engineering. This paper reviews the background to the study of concrete and the current international research developments. Recent accomplishments in the world are summarized on four levels—environment, materials, components, structure. Finally, directions of future research are also proposed.

The Summary of the Durability of Concrete Parameters Calculation Models

2011 ◽  
Vol 71-78 ◽  
pp. 937-944
Author(s):  
Ping Jie Cheng ◽  
Han Zhou Hu ◽  
Shu Guang Hu
Keyword(s):  
Environmental Effects ◽  
Concrete Structure ◽  
Civil Engineering ◽  
Steel Corrosion ◽  
Type Model ◽  
Model Parameters ◽  
Source Type ◽  
Important Field ◽  
Parameters Calculation ◽  
Durability Of Concrete

The durability of concrete structure has become an important field of civil engineering at home and abroad, and how to determine the environmental effects of typical durability of concrete structure key parameters become the key. Proposed by different domestic and foreign scholars to study durability parameters of concrete structure of different models, different models are different in the source, type, model parameters and applicable conditions. In this paper, some typical models are reviewed and analyzed from two major aspects of the durability of concrete, the deterioration of concrete and the steel corrosion.

scholarly journals Vibration Properties of a Concrete Structure with Symmetries Used in Civil Engineering

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 656
Author(s):  
Sorin Vlase ◽  
Marin Marin ◽  
Ovidiu Deaconu
Keyword(s):  
Dynamic Analysis ◽  
Concrete Structure ◽  
Current Practice ◽  
Civil Engineering ◽  
Engineering Practice ◽  
Design Time ◽  
Vibration Properties ◽  
Reduced Costs ◽  
Constructive Simplicity ◽  
Economic Considerations

The paper aims to study a concrete structure, currently used in civil engineering, which has certain symmetries. This type of problem is common in engineering practice, especially in civil engineering. There are many reasons why structures with identical elements or certain symmetries are used in industry, related to economic considerations, shortening the design time, for constructive, simplicity, cost or logistical reasons. There are many reasons why the presence of symmetries has benefits for designers, builders, and beneficiaries. In the end, the result of these benefits materializes through short execution times and reduced costs. The paper studies the eigenvalue and eigenmode properties of vibration for components of the constructions’ structure, often encountered in current practice. The identification of such properties allows the simplification and easing of the effort necessary for the dynamic analysis of such a structure.

scholarly journals Effects of Anti-Graffiti Protection on Concrete Durability

2014 ◽  
Vol 634 ◽  
pp. 517-526 ◽  
Author(s):  
Elsa Neto ◽  
Ana Souto ◽  
Aires Camões ◽  
Arlindo Begonha ◽  
Paulo Cachim
Keyword(s):  
Water Absorption ◽  
Atmospheric Pressure ◽  
Surface Characteristics ◽  
Concrete Surface ◽  
Experimental Program ◽  
Concrete Durability ◽  
Protection Systems ◽  
Before And After ◽  
Paint Removal ◽  
Durability Of Concrete

The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti, a form of vandalism that causes a major social and economic impact on society. Concrete is a porous material sometimes deteriorated over the years, and the interactions between the inks and the substrate and removal methods sometimes deteriorate or alter the concrete surface, especially if it is necessary to repeat the removal process. The anti-graffiti products are applied on the surface of the concrete, hindering the adhesion of paints or preventing its penetration into the pores of concrete, which in turn facilitates their removal. However, it appears that many of the existing protective products on the market may also alter the surface characteristics of the concrete irreversibly. Considering that the durability of concrete depends on the composition and characteristics of the surface, it is essential to know the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes in durability indicators and surface properties that protect concrete from deterioration (i) concrete without protection before and after application of spray paint, (ii) concrete with protection before and after application of spray paint and (iii) after paint removal were studied. Two anti-graffiti products were evaluated: a permanent and a sacrificial one. Effects of the anti-graffiti systems on the concrete durability are investigated and the tests performed include: water absorption by capillary and immersion at atmospheric pressure. The results of the water absorption tests show that the graffiti protection reduces the water absorption into the concrete and facilitates the removal of the graffiti without affecting negatively the characteristics of the surface and thus contributing to improve its durability.

The Law Technology Study and the Mechanism Analysis of Small-Size Machined by Electro Jet Machining

2012 ◽  
Vol 499 ◽  
pp. 179-185
Author(s):  
Zhi Bo Yin ◽  
Fu Yuan Li ◽  
C.X. Wang
Keyword(s):  
Duty Cycle ◽  
Material Removal ◽  
Electrochemical Machining ◽  
Corrosion Mechanism ◽  
Mechanism Analysis ◽  
Technology Study ◽  
Original Experiment ◽  
The Law ◽  
Faraday Law ◽  
Main Factor

In order to research the Law technology and the equipment performance of Electro Jet, The institute developed an electro jet machine. Through a large number of experiments on this machine, the author concluded its process law and analysis the corrosion mechanism to the removed process. The results show that, duty cycle and frequency have a certain effect on the machine accuracy, and duty cycle is the main factor of aperture morphology. When duty cycle varies from 30%~40%, the stray corrosion is less. Frequency affects the depth seriously, based on the original experiment, voltage, duty cycle. Frequencies were not interactive within the scope of the study. The corrosion of anodic workpiece satisfies Faraday law by the study of material removal mechanism. Current efficiency is less than 1, and it’s 40%~60%.current density is 2~4.5A/mm2, that is larger than ordinary electrochemical machining.

scholarly journals Study on Corrosion Monitoring of Rebar in Concrete Structure under Service with Electrochemical Impedance Spectroscopy

2018 ◽  
Vol 67 (2) ◽  
pp. 83-87 ◽  
Author(s):  
Hiroyuki Tokieda ◽  
Tatsuki Okamoto ◽  
Yoshinao Hoshi ◽  
Isao Shitanda ◽  
Masayuki Itagaki
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Concrete Structure ◽  
Electrochemical Impedance ◽  
Corrosion Monitoring

scholarly journals The analysis of return on speculative trading with futures contracts of agriculture commodities in the context of the currency risk

2007 ◽  
Vol 55 (3) ◽  
pp. 133-142
Author(s):  
Oldřich Šoba
Keyword(s):  
Exchange Rate ◽  
Futures Contracts ◽  
Financial Assets ◽  
Agricultural Commodities ◽  
Currency Risk ◽  
Futures Contract ◽  
The World ◽  
Speculative Trading ◽  
Relative Change ◽  
Main Factor

The paper is focused on analysis of return on speculative operations with futures contracts from the view of participators not undertaking and undertaking the currency risk. The currency risk is determined by unexpected change of relevant exchange rate (currency denomination of futures contracts / domestic currency of participator). The paper analyses the basic factors influencing the profitability of these operations such as relative change of futures contract value, leverage incidence and relative change of relevant exchange rate. The paper is focused on futures contracts of the world most important agricultural commodities. The conclusion of the paper for participators not undertaking the currency risk is following: The relative change of futures contract is main factor for the calculation of return on speculative operation. This change is multiplied by leverage incidence finally. The conclusion of the paper for participators undertaking the currency risk is following: The relative change of relevant exchange rate is not usually relevant for the calculation of return on speculative operation. Main factor is the relative change of futures contract because this change is multiplied by leverage incidence finally but the relative change of relevant exchange rate isn’t.Neverthless the conclusions of this paper are not valid only for futures contracts of agricultural commodities but generally also for other commodity futures contracts and futures contracts where underlying assets are not commodities but for example financial assets.

Aesthetic needs in professional activity of future teacher of music: theoretical aspect of the problem

2020 ◽  
Author(s):  
Vyshnevetska Maryna ◽  
Keyword(s):  
Professional Training ◽  
Human Life ◽  
Theoretical Aspect ◽  
Music Teacher ◽  
Necessary Condition ◽  
Professional Activity ◽  
Human Needs ◽  
The World ◽  
Main Factor

The paper considers the issue of developing aesthetic needs of a future music teacher in the course of professional training. The author defines notions such as culture, aesthetic culture, aesthetic activity as well as explores the essence of the notion of an aesthetic need of a future music teacher. The paper substantiates the role of art and aesthetic activity as the main factor for aesthetic needs development. The study reveals that there is a reason for the interest to human needs since a large number of branches in material and spiritual culture of society depend on defining the nature of needs and trends in their development. The author emphasises that the functioning of all levels of human life requires needs that would meet human development both physically and emotionally, thus, there should be an aesthetic form of activity because it harmoniously combines both spiritual and functional aspects. The paper substantiates the role of art as the main factor for development of aesthetic needs that can be met in various activities, but it is in art that they find the greatest expression. The author supports the idea that art is a special area of human existence and it combines knowledge and communication, intelligence, a sense of morality, and imagination of people. Involvement of a person in art is a necessary condition for development of aesthetic consciousness since elevation of the spirit and actualization of an essential aesthetic force take place during the process of perception, experience and understanding of works of art. Art integrates a dialogue of a person with the world. Considering the concept of an aesthetic need, the author defines it as an internal need to comprehend certain aesthetic values, development of certain skills, because an aesthetic need is based on aesthetic feelings that are embodied in aesthetic tastes and consist of individual selection of those aesthetic phenomena and objects that best suit views and interests of a person. The paper emphasises that an aesthetic need embodies richness and diversity of spirituality of a person who seeks to fulfill their potential in all fullness of life and if a person has a need for personal fulfillment, they will find the strength and ways to do that. It has been proved that an aesthetic need has semantic and aesthetic properties and has an artistic and perceptual nature, which provides an opportunity to obtain pleasure, enjoyment, joy, delight from beauty. It has been established that the process of perception or direct creativity of art are characterized by a combination of a goal and means, where the means develop into the goal, and the goal is the process itself when spiritual, functional and aesthetic needs of the individual are met, i.e. a person reaches a certain level in their activity when they create products and forms of cultural activity that meet more and more of their needs. The paper outlines that an emerging aesthetic need motivates a music teacher to create conditions and means for achieving satisfaction with their own creative activities, because an aesthetic need is a desire of a future music teacher to harmonize the internal and external world as well as development of aesthetic awareness of the world: to perceive and appreciate the beauty, to live and create according to the laws of beauty.

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