scholarly journals Evaluation and improvement of the quality of Senegalese reinforcing steel bars produced from scrap metals

2009 ◽  
Vol 30 (3) ◽  
pp. 804-809
Author(s):  
Mamadou Babacar Ndiaye ◽  
Sandrine Bec ◽  
Bernard Coquillet ◽  
Ibrahima Khalil Cisse
2017 ◽  
Author(s):  
Parmo

The city development in Indonesia is more oriented to the overground space and this is because the urban population has increased significantly and it is incomparable with the land available in the cities. The number of high-rise buildings and skyscrapers also marks this phenomenon. However, high-rise buildings and skyscrapers have the potential to be vulnerable to the earthquake hazard in Indonesia particularly those located at the high risk seismic regions. In the design of seismic resistant buildings, there are two important aspects required to be considered, namely strength and ductility. The deformation capability and better innovative reinforcement connection become primary consideration in the design of seismic resistant structures. From the tensile tests of reinforcing steel bars with clamps, it is shown that D13 bars has the yield and ultimate tensile strengths of 270.69 and 351.45 MPa, respectively, with the maximum load of 4,757 kg and the maximum elongation of 40%. As for the D16 bars, the yield and ultimate tensile strengths of 217.80 and 327 605 MPa, respectively, with the maximum load of 6,717 kg and the elongation of 32%. In the study, two pieces of steel clamps were tested, it is found that to obtain better results there is a need to increase the number and improve the quality of material of the steel clamps.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hui Chen ◽  
Jinjin Zhang ◽  
Jin Yang ◽  
Feilong Ye

The tensile behaviors of corroded steel bars are important in the capacity evaluation of corroded reinforced concrete structures. The present paper studies the mechanical behavior of the corroded high strength reinforcing steel bars under static and dynamic loading. High strength reinforcing steel bars were corroded by using accelerated corrosion methods and the tensile tests were carried out under different strain rates. The results showed that the mechanical properties of corroded high strength steel bars were strain rate dependent, and the strain rate effect decreased with the increase of corrosion degree. The decreased nominal yield and ultimate strengths were mainly caused by the reduction of cross-sectional areas, and the decreased ultimate deformation and the shortened yield plateau resulted from the intensified stress concentration at the nonuniform reduction. Based on the test results, reduction factors were proposed to relate the tensile behaviors with the corrosion degree and strain rate for corroded bars. A modified Johnson-Cook strength model of corroded high strength steel bars under dynamic loading was proposed by taking into account the influence of corrosion degree. Comparison between the model and test results showed that proposed model properly describes the dynamic response of the corroded high strength rebars.


Author(s):  
Marina C. Vasco ◽  
Panagiota Polydoropoulou ◽  
Apostolos N. Chamos ◽  
Spiros G. Pantelakis

In a series of applications, steel reinforced concrete structures are subjected to fatigue loads during their service life, what in most cases happens in corrosive environments. Surface treatments have been proved to represent proper processes in order to improve both fatigue and corrosion resistances. In this work, the effect of corrosion and sandblasting on the high cycle fatigue behavior reinforcing steel bars is investigated. The investigated material is the reinforcing steel bar of technical class B500C, of nominal diameter of 12 mm. Steel bars specimens were first exposed to corrosion in alternate salt spray environment for 30 and 60 days and subjected to both tensile and fatigue tests. Then, a series of specimens were subjected to common sandblasting, corroded and mechanically tested. Metallographic investigation and corrosion damage evaluation regarding mass loss and martensitic area reduction were performed. Tensile tests were conducted after each corrosion exposure period prior to the fatigue tests. Fatigue tests were performed at a stress ratio, R, of 0.1 and loading frequency of 20 Hz. All fatigue tests series as well as tensile test were also performed for as received steel bars to obtain the reference behavior. The results have shown that sandblasting hardly affects the tensile behavior of the uncorroded material. The effect of sandblasting on the tensile behavior of pre-corroded specimens seems to be also limited. On the other hand, fatigue results indicate an improved fatigue behavior for the sandblasted material after 60 days of corrosion exposure. Martensitic area reductions, mass loss and depth of the pits were significantly smaller for the case of sandblasted materials, which confirms an increased corrosion resistance.


2006 ◽  
Vol 20 (9) ◽  
pp. 782-789 ◽  
Author(s):  
Ch.Alk. Apostolopoulos ◽  
M.P. Papadopoulos ◽  
Sp.G. Pantelakis

2019 ◽  
Vol 199 ◽  
pp. 359-368 ◽  
Author(s):  
Dawang Li ◽  
Ren Wei ◽  
L. Li ◽  
Xiaotao Guan ◽  
Xuming Mi

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