© 2019 IJRAR June 2019, Volume 6, Issue 2 www.ijrar.org (E-ISSN 2348-1269, P- ISSN 2349-5138) IJRAR2001660 International Journal of Research and Analytical Reviews (IJRAR) www.ijrar.org 648 Critical Review on effect of Chloride Penetration on Concrete and Various Rapid Chloride Penetration Tests Methods Tarun Gehlot 1 , Dr. Suresh Singh Sankhla 2 , Krishan Kumar Saini 3 1 P.hD. Scholar, Department of Structural Engineering, MBM Engineering College, Jodhpur, Rajasthan, India 2 Associate Professor, Department of Structural Engineering, MBM Engineering College, Jodhpur, Rajasthan, India 3 P.hD. Scholar, Department of Structural Engineering, MBM Engineering College, Jodhpur, Rajasthan, India Abstract: This comprehensive research paper presents critical review of literature on effects of chloride ion penetration into the concrete with respect to the durability characteristics. Chloride-induced corrosion of steel reinforcement is one of the major threats to durability of reinforced concrete structures in a marine environment. Chloride environments pose a threat to the durability and service life of reinforced concrete structures It is therefore, necessary to use rapid chloride test methods to assess a concrete’s potential t o retard chloride ion diffusion, for design and quality assurance purposes. This research paper briefly explains the mechanism of various test which is conducted to evaluate chloride penetration of concrete .This paper explore role of mineral admixtures in concrete durability, the methods of measuring the chloride ingress into concrete, the challenges in assessing concrete durability from its chloride diffusivity, and the service life modelling of reinforced concrete in chloride-laden environments. Keywords: Durability, RCPT , chloride , concrete, CTH, etc 1 INTRODUCTION In an environment exposed to seawater, chloride-induced corrosion of reinforcing steel is the most important deterioration mechanism of reinforced concrete structures. Under chloride attack, the reinforcing steel corrodes more easily The volume of the corrosion products is about four to six times larger than the steel This volume increase would induce internal tensile stresses in the cover concrete, resulting in cracking, de lamination and spalling. Therefore, in the durability design of these structures, the most important factor that determines their service life is the chloride transport properties of the concrete. (Mehta and Monteiro, 2006).Extensive studies have been conducted over the past decades to study the chloride transport properties of concrete. Most of the studies were carried out on sound and un cracked concrete (Zhang and Gjorv, 1996; Wang etal., 2005; Song etal., 2008; Pack etal., 2010). However, in most cases, cracks (micro cracks) may exist in reinforced concrete structures for different reasons. A restrained volume change is one of the most common causes of cracks in concrete. Concrete will shrink during the hydration process. If the shrinkage is restrained, tensile stress will develop. Once the stresses exceed the tensile strength of the concrete, cracks will occur (Carino and Clifton, 1995).. Durability problems also can lead to cracks, such as freeze- thaw action, alkali-aggregate reaction, sulfate ingress, and corrosion of reinforcement. Other reasons for concrete cracking could lie in poor construction practices, construction over load errors in design and externally applied loads (ACI 224.1R-07, 2007). Several studies have focused on the effect of cracks on the chloride transport properties of concrete using both experiments andnumericalsimulations(RodriguezandHooton, 2003;Kato etal.,2005;Şahmaran, 2007;Ismail etal2008;Wang etal. 2009;Ishida etal.; 200 9;Jin etal., 2010; Wang and Ueda, 2011; Lu et al., 2012; savija etal., 2013). Permeation is yet another mechanism by which penetration of chloride ions can occur which is driven by pressure gradients. Consider a closed volume made of concrete whose inside bottom face is under hydrostatic pressure caused due to a liquid and if the same also contain chloride ion then permeation would occur. Absorption through capillary is yet another mechanism through which chloride ingress occurs. Concrete surfaces that are exposed to alternate wetting & drying conditions often undergo chloride ingress by this mechanism. In such conditions, where concrete comes in contact with water containing chlorides then, as mentioned above, due to a moisture gradient capillary suction pressure develops and absorption of chloride ions through the pores occurs. Interesting here would be to note that unless the concrete quality is very poor the absorption of chloride ions by this mechanism would not reach the reinforcing steel because the depth of drying is usually quite small. Though still it does assist in bringing the chlorides inside concrete and reducing the distance that needs to be covered to reach the steel [Thomas, et al., 1995]. 2 CHLORIDE DIFFUSION: A BRIEF REVIEW Considering a one-dimensional state for simplicity’s sake, Fick’s law that governs the diffusion of chloride ions into Chloride states: J = - Deff   Here, J denotes the flux of chloride ions, Deff denotes the effective diffusion coefficient C specifies the concentration of chloride ions and x is a position variable. Talking in practical terms, the equation written above is useful only once the steady- state conditions have been reached, i.e. the concentration of ions does not change with time. Ficks’s second law comes to rescue