Strength Evaluation of Welded Lap Splices of 19 and 29 mm Normal Reinforcing Steel Bars

2017 ◽  
Vol 29 (5) ◽  
2016 ◽  
Vol 845 ◽  
pp. 132-139
Author(s):  
Mochamad Teguh ◽  
Novia Mahlisani

The limited lengths of reinforcing bars have been commonly found in the practical construction of most reinforced concrete structures. The required length of a bar may be longer than the available stock of steel length. For maintaining desired continuity of the reinforcement in almost all reinforced concrete structures, some reinforcing bars should be carefully spliced. In the case of long flexural beam, bar installers end up with two or even more pieces of steel that must be spliced together to accomplish the desired steel length. An experimental study was conducted to investigate flexural behavior of reinforced concrete beams utilizing a variety lap splices of reinforcing steel bars under two-point loading. Five variations of lap splices of reinforcing steel bars positioned at midspan of tensile reinforcement of the beam were investigated. Welded joints and overlapped splices were used to construct the variation of lap splices of reinforcing steel bars. The general trend in crack pattern, the load deflection characteristics and the mode of failure of flexural beams under two-point loading were also observed. The flexural strength comprising load-displacement response, flexural crack propagation, displacement ductility is briefly discussed in this paper.


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

Author(s):  
Jorge E. Egger ◽  
Fabian R. Rojas ◽  
Leonardo M. Massone

AbstractLow cycle fatigue life of high-strength reinforcing steel bars (ASTM A706 Grade 80), using photogrammetry by RGB methodology is evaluated. Fatigue tests are performed on specimens under constant axial displacement with total strain amplitudes ranging from 0.01 to 0.05. The experimental observations indicate that buckling of high-strength reinforcing bars results in a damaging degradation of their fatigue life performance as the slenderness ratio increases, including an early rebar failure as the total strain amplitude increases since it achieves the plastic range faster. In addition to this, the results show that the ratio of the ultimate tensile strength to yield strength satisfies the minimum of 1.25 specified in ASTM A706 for reinforcement. On the other hand, the RGB methodology indicates that the axial strains measured by photogrammetry provide more accurate data since the registered results by the traditional experimental setup do not detect second-order effects, such as slippage or lengthening of the specimens within the clamps. Moreover, the RGB filter is faster than digital image correlation (DIC) because the RGB methodology requires a fewer computational cost than DIC algorithms. The RGB methodology allows to reduce the total strain amplitude up to 45% compared to the results obtained by the traditional setup. Finally, models relating total strain amplitude with half-cycles to failure and total strain amplitude with total energy dissipated for multiple slenderness ratios (L/d of 5, 10, and 15) are obtained.


2018 ◽  
Vol 164 ◽  
pp. 877-887 ◽  
Author(s):  
Binbin Zhou ◽  
Xianglin Gu ◽  
Hongyuan Guo ◽  
Weiping Zhang ◽  
Qinghua Huang

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