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International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 11 Issue: 08 | Aug 2024

p-ISSN: 2395-0072

www.irjet.net

Flexural response of corroded RC members: A review Manpreet Singh Bains1, Prof. Yuvraj Singh2, Prof. Harvinder Singh3 1PG Student, Guru Nanak Dev Engineering College, Ludhiana, Punjab, India

2Assistant Professor, Guru Nanak Dev Engineering College, Ludhiana, Punjab, India 3Professor, Guru Nanak Dev Engineering College, Ludhiana, Punjab, India

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Abstract - The durability of reinforced concrete (RC)

protects the rebars from corrosion. The passive layer is destroyed by the ingress of chlorine ions and carbonation attack from the surrounding environment. The rust products formed due to corrosion have a much higher volume than the original volume of rebar, which leads to the cracking of the concrete cover [9], [10], [11], [12].

structures is significantly compromised by the corrosion of reinforcement bars (rebars), which poses a serious threat to their performance and longevity. Corrosion leads to an increase in rebar volume, induces crack formation, and reduces the cross-sectional area of the reinforcement. These changes weaken the bond between concrete and rebar, resulting in increased slippage and a substantial reduction in the flexural strength of RC beams. Consequently, the loadcarrying capacity, ductility, and service life of the structure are reduced, raising concerns about its safety. Corroded beams often exhibit behaviour contrary to their design intentions, with early failure occurring due to the rupture of weakened rebars. Understanding the effects of corrosion on RC beams at various stages of degradation is therefore critical. This review synthesizes research findings on the flexural response of corroded RC members, highlighting the key factors influencing their degradation and the resulting structural outcomes.

Corrosion degrades the properties of RC members. It results in reduced load-carrying capacity, compromised ductility, concrete-rebar bond deterioration, crack origination and propagation, and spalling of the concrete cover. The cracks and spalling provide space for moisture to enter the concrete, further making it more prone to corrosion [12]. The corrosion can be divided into two types, namely uniform corrosion, and pitting corrosion. The corrosion of the rebars throughout its length is known as uniform corrosion. Pits form on surface of rebar at random locations, such that the rebar cannot be classified into category of uniform corrosion is known as pitting corrosion. Pitting corrosion is much severe than uniform corrosion. Flexural strength is the resistant of members to failure in bending. Beams and slabs are specially designed to sustain bending stresses. Damage caused by corrosion may also have a negative impact on load bearing behavior of members throughout their lifespan. Depending on the level of exposure and the level of the protection, the deterioration process begins at the beginning and continues at a corrosion rate. Since corrosion cannot always be prevented, it is important to make sure that structural performances are preserved and do not deteriorate because of corrosion [13]. Accurate data regarding the serviceability and load carrying capacity of corroded reinforcing steel beams is crucial and a topic of extensive research [14].

Key Words: Flexural strength, rebar corrosion, residual capacity, RC members, structural degradation

1. INTRODUCTION Concrete is a major construction material used throughout the world. It is well known for its compressive strength, durability and can be moulded to any required shape. It deteriorates with time and requires huge costs for its repairs and maintenance. Therefore, it becomes essential to consider the problems associated with the use of concrete, when using it for a specific purpose. Strength, service life, losses, cost-effectiveness, and environmental impacts are the factors considered before using it for respective purposes [1], [2]. Besides its applications, it has some limitations too. It is weak in tension, formation of wide cracks, brittleness, shrinkage, and creep.

In natural environments, reinforcement corrosion is a slow process that is influenced by a number of variables, including moisture, humidity, oxygen, aggressive conditions, concrete quality, and the ratio of reinforcement to concrete. It can take years to notice the first corrosion crack on a concrete surface under typical exposure conditions, which makes it challenging to quickly examine the detrimental effects of reinforcement corrosion on the structural performances of RC structures. Therefore, to achieve a target amount of reinforcement corrosion in a short duration of time, the corrosion process is accelerated [15]. Fig-1 presents a deteriorated concrete beam.

To impart the tensile strength to concrete, steel reinforcement bars are embedded into it. [3]. Plain concrete is much more resistant to marine environments whereas the reinforcement bars in reinforced concrete undergo selfdamages, which adversely affects the properties of concrete [4], [5]. Reinforcement bars are susceptible to corrosion due to the aggressive environment in which the members are present [6]. Marine structures are mostly affected by the corrosion of reinforcement bars [7], [8]. Steel reinforcement bars have a passive layer of concrete around them, which

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