scholarly journals Acoustic Inspection of Coated Steel Bar in Reinforced Concrete Structure

Author(s):  
Chih-Hung Chiang ◽  
Cho-Liang Tsai
2015 ◽  
Vol 754-755 ◽  
pp. 373-377 ◽  
Author(s):  
Mustaqqim Abdul Rahim ◽  
Zuhayr Md Ghazaly ◽  
Muhammad Azizi Azizan ◽  
Fazdliel Aswad Ibrahim ◽  
Norlia Mohamad Ibrahim ◽  
...  

In the normal practice in the reinforced concrete design, the main reinforcement steel bar and links was used to fabricate the concrete structure. However new materials such as steel fiber has been introduced as the reinforcement to the reinforced concrete structure [1]. Nowadays, the application of fiber in concrete increase slightly as an engineering material demands. Fibers have distinctive of geometry, size and material. The characteristics and properties of fiber influence the properties concrete. Steel, glass and synthetic fibers were used in concrete in 1960s because of the difficulty to handle the asbestos fiber [2].


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Xiwu Zhou ◽  
Runcheng Zhang ◽  
Ruisheng Xiong ◽  
Guoxue Zhang ◽  
Xiangyu Wang

The reinforced concrete structure of a port wharf is affected by steel corrosion and ship docking impact. Replacing an ordinary steel bar with a stainless steel bar can solve the corrosion problem of the steel bar while ensuring the bearing capacity of the structure. However, the research on impact resistance of stainless steel-reinforced concrete structure is not perfect. In this paper, impact mechanical properties of reinforced concrete beams before and after equal strength replacement of stainless steel bars are analyzed by theoretical analysis and drop hammer impact test, and the possibility and applicable scope of equal strength replacement of stainless steel bars are put forward. The results indicated the following: (1) when the reinforcement ratios were small (0.21% to 1.32%), the stainless steel-reinforced concrete beams with equal strength were able to effectively reduce the stiffness losses of the beams undergoing impact loads, as well as improve the elastic resilience abilities, and reduce the structural damages. Therefore, the corrosion and impact problems of reinforcements could be solved by replacing ordinary reinforcements with stainless steel reinforcements and (2) when the reinforcement ratios were large (1.32% to 2.57%), the shear failures of the stainless steel-reinforced concrete beams were observed to be relatively serious, and the impact resistance performances had worsened. The research results provide technical support for the engineering application of stainless steel-reinforced concrete structure design.


2010 ◽  
Vol 36 ◽  
pp. 176-181
Author(s):  
Xian Feng He ◽  
Shou Gang Zhao ◽  
Yuan Bao Leng

The corrosion of steel will have a bad impact on the safety of reinforced concrete structure. In severe cases, it may even be disastrous. In order to understand the impact of steel corrosion on the structure, tests are carried out to study corrosion and expansion rules of steel bars as well as the impact rules of corrosion on bond force between steel and concrete. The results show that wet and salty environment will result in steel corrosion; relatively minor corrosion will not cause expansion cracks of protection layers; when steel rust to a certain extent, it will cause cracks along the protection layer; when there exists minor corrosion in steel and the protection layer does not have expansion cracks, the bond force is still large and rapidly decreases as the corrosion rate increases.


2021 ◽  
Author(s):  
Lisa Ptacek ◽  
Alfred Strauss ◽  
Clémence Bos ◽  
Martin Peyerl

<p>The curing of concrete is extremely important for the durability of a reinforced concrete structure. In practice, due to the complex construction processes, the very limited phases and the lack of control, aftertreatment is often neglected by executing companies. Hence infrastructure operators are therefore very interested in having a robust, simple tool that enables aftertreatment to be easily checked and, as a result, to convey the importance of this process step to the client. In the project presented here, classic and novel test methods are presented and discussed, as well as their suitability for the detection of the aftertreatment quality on laboratory samples and subsequently on some real structures.</p>


2018 ◽  
Vol 8 (11) ◽  
pp. 2116 ◽  
Author(s):  
Rodrigo Díaz ◽  
Hui Wang ◽  
Herbert Mang ◽  
Yong Yuan ◽  
Bernhard Pichler

A 1:4 scaled fire test of a segment of a subway station is analyzed by means of three-dimensional Finite Element simulations. The first 30 min of the test are considered to be representative of a moderate fire. Numerical sensitivity analyses are performed. As regards the thermal boundary conditions, a spatially uniform surface temperature history and three different piecewise uniform surface temperature histories are used. As regards the material behavior of concrete, a temperature-independent linear-elastic model and a temperature-dependent elasto-plastic model are used. Heat transfer within the reinforced concrete structure is simulated first. The computed temperature evolutions serve as input for thermomechanical simulations of the fire test. Numerical results are compared with experimental measurements. It is concluded that three sources of uncertainties render the numerical simulation of fire tests challenging: possible damage of the structure prior to testing, the actual distribution of the surface temperature during the test and the time-dependent high-temperature behavior of concrete. In addition, the simulations underline that even a moderate fire represents a severe load case, threatening the integrity of the reinforced concrete structure. Tensile cracking is likely to happen at the inaccessible outer surface of the underground structure. Thus, careful inspection is recommended even after non-catastrophic fires.


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