Influence of chloride threshold value in service life prediction of reinforced concrete structures

Abstract

Extensive studies have been reported on the development of service-life prediction of reinforced concrete structures in the last two decades. Service life of a reinforced concrete structure is dependent on the corrosion process, specifically chloride threshold value. Chloride threshold value is a distinctive property and is dependent on several factors such as the supplementary cementitious material used, presence of surface cracks, water to binder ratio, type of steel reinforcement, exposure conditions, measurement methods, etc. Although chloride threshold value is an influential parameter in service-life prediction, a definitive chloride threshold value considering these factors is not reported in the existing literature and standards. Moreover, values adopted in many analytical tools for service life predictions based on the type of steel reinforcement alone are not appropriate and leads to inaccurate calculations. There is a gap in the available literature in understanding the selection of suitable chloride threshold values to be adopted for a specific system. Therefore, it is imperative to study the variation of chloride threshold value with exposure conditions as well as other influencing parameters, to achieve proper service life prediction. In the paper, several influencing parameters on chloride threshold value and its significance on prediction method are comprehensively reviewed. Moreover, suitable recommendations are highlighted for Indian and international standards at the later part of the study.

Impact of the corrosion inhibitors in the durability of concrete structures

“…The initiation phase represents the period it takes for chloride ions to penetrate the concrete coating and reach the chloride threshold content on the surface of the steel causing the removal of the passive layer. This critical chloride content is not a specific value but depends on countless factors such as the aggressiveness of the environment, the ratio a/c, the type of cement used, the presence of cracks in the surface, the impurities present in the concrete, and the state of the steel surface [29].…”

A whole life cycle performance-based ECOnomic and ECOlogical assessment framework (ECO2) for concrete sustainability

“…The chloride threshold potential of a concrete mix is dependent on a set of exposure conditions such as temperature, RH and % of free chlorides as well as intrinsic variables such as the concrete type and w/b ratio [55]. A standard test to measure the resistance of a concrete mix to chloride penetration is called Rapid Chloride Penetration Test (RCPT) according to ASTM C1202-18 [56]. In order to predict the value for the chloride diffusion coefficient D nssm , the following data in table 2 was extracted from the literature for specific concrete types and mixes.…”

A Systematic Review of the Discrepancies in Life Cycle Assessments of Green Concrete

“…2019, 9, x FOR PEER REVIEW 9 of 26 were tested after 90 days of curing instead of the common 28, at which the pozzolanic reaction would mature and most BCC mixes would achieve comparable strength to that of OPCC [70]. According to Mahima et al [71], premature concrete deterioration, due to carbonation and chloride penetration, is responsible for a loss of 2.2 trillion USD, which is equivalent to 3% of the world's gross domestic product (GDP). This means that durability is a more detrimental factor to the performance of concrete than that of the compressive strength.…”

“…The user's choice for a unit-based LOD could be based on a personal preference or absence of the necessary details about the project, such as the quantity of concrete per member or per a whole structure. However, the benefit of studying the member or a whole structure in which the concrete According to Mahima et al [71], premature concrete deterioration, due to carbonation and chloride penetration, is responsible for a loss of 2.2 trillion USD, which is equivalent to 3% of the world's gross domestic product (GDP). This means that durability is a more detrimental factor to the performance of concrete than that of the compressive strength.…”