Evaluation and modeling of ultimate bond strength of corroded reinforcement in reinforced concrete elements

2015 ◽  
Vol 49 (8) ◽  
pp. 3195-3215 ◽  
Author(s):  
Esra Mete Güneyisi ◽  
Kasım Mermerdaş ◽  
Ayşegül Gültekin
2011 ◽  
Vol 71-78 ◽  
pp. 1057-1061 ◽  
Author(s):  
Ke Fang Yin ◽  
Yang Han ◽  
Yi Liu

With the centrally pulling-out test, the bond strength of reinforced concrete is measured with different temperatures and different cooling ways after high temperature; and the ultimate bond strength and slip of reinforced and concrete under different conditions are analyzed. The results show that the bonding strength declines gradually with the increase of temperature, and the ultimate slippage also decreases gradually.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Haifeng Yang ◽  
Zhiheng Deng ◽  
Yinghong Qin ◽  
Liangsheng Lv

This paper investigated bond-slip characteristics of chloride-induced corroded reinforced concrete incorporating different levels of recycled concrete aggregates (RCA). Pullout tests were adopted to evaluate the bonding and debonding behaviors of the embedded rebar experiencing different corrosion levels. Both high- and low-strength concrete were considered. Bond-slip curves were recorded to determine the influences of rebar corrosion levels and RCA replacements on the bond strength and debonding energy of the specimens. Test results indicate that increasing rebar corrosion level gradually weakens the antisliding ability of reinforced recycled aggregate concrete (RAC) except for a small level corrosion and the degradation rate of ultimate bond strength increases with a decrease of compressive strength at 0.5% rebar corrosion. The results also demonstrate that the ultimate bond strength of reinforced RAC slightly decreases with an increase of RCA replacement. However, the relative bond strength between uncorroded rebar and RAC is little affected by RCA content, while it decreases with an increase of RCA replacement in high-strength specimens after rebar corrosion. The debonding energy between deformed rebar and RAC is found decreasing with the increment of the rebar corrosion level and increasing with an increase of RAC content.


2018 ◽  
Vol 195 ◽  
pp. 01016
Author(s):  
Stefanus Kristiawan ◽  
Bambang Santosa ◽  
Edy Purwanto ◽  
Rachmad A. Caesar

Strengthening of reinforced concrete elements can be carried out using a variety of materials and techniques. One of such materials is textile reinforced concrete (TRC). This material consists of a matrix, usually made of mortar, and textile as reinforcement. This study aims to produce mortar that meets the characteristic of a TRC matrix with respect to an adequate bond strength. The type of mortar developed in this study was fibre reinforced polyvinyl acetate (PVA) modified mortar. The bond strength of this material to the parent concrete was tested by the slant shear method. The results indicate that the amount of PVA content affects the magnitude of the bond strength. The higher the PVA content, the higher the bond strength. The results also confirm that the relationship between the bond strengths and their corresponding compressive strengths tends to be linear.


2001 ◽  
Vol 28 (5) ◽  
pp. 787-793 ◽  
Author(s):  
Rami H Haddad ◽  
Ahmed M Ashteyate

An experimental study was conducted to investigate the bond behavior between corroding reinforcing steel and surrounding synthetic fiber reinforced concrete. Pullout concrete and fiber reinforced concrete specimens were prepared at concrete cover to steel bar diameter ratios of 3.1 and 3.7 with three embedded lengths of 100, 200, and 300 mm. Fiber reinforced concrete was prepared using polypropylene at 0.15% and 0.30% or nylon fibers at 0.3% by mix volume. After moist curing for 90 days, pullout specimens, originally contaminated by up to 11 kg/m3 NaCl, were subjected to a special treatment to accelerate corrosion in steel. The bond stress–slippage relationship was evaluated at different corrosion levels. The findings indicated that the use of fibers delayed initiation of cracking, due to steel corrosion, and improved the ultimate bond strength at cracking and post-cracking stages. The percentage improvement in ultimate bond strength at the latter stages reached as high as 52% and 87%, respectively. It was noticed that, prior to cracking, corrosion of steel bars resulted in an increase in bond strength, regardless of the concrete cover to bar diameter ratio used, or whether fibers were used or not. After cracking (due to steel corrosion), pullout specimens prepared with polypropylene fibers showed better resistance than that of corresponding ones with nylon fibers.Key words: fibers, reinforced concrete, corrosion, cracking, bond strength, slippage.


2018 ◽  
Vol 169 ◽  
pp. 425-435 ◽  
Author(s):  
Ayman Shamseldein ◽  
Hany Elshafie ◽  
Ahmed Rashad ◽  
M. Kohail

Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.


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