Link points to Internet Archive / others. Not hosted by InfraLens. Details
IS 14958:2001 is the Indian Standard (BIS) for migrating corrosion inhibitors - specification. This standard specifies the requirements for migrating corrosion inhibitors (MCIs) used as admixtures in concrete. It covers physical, chemical, and performance criteria to ensure the inhibitor does not harm concrete properties while effectively reducing the corrosion rate of embedded steel reinforcement.
Specifies requirements for migrating corrosion inhibitors used to protect steel reinforcement in concrete.
Overview
Status
Current
Usage level
Specialized
Domain
Materials Science — Admixtures and Chemical Products for Concrete
! MCIs are particularly effective in new construction in corrosive environments (e.g., coastal areas) and in the repair of chloride-contaminated structures.
! Always conduct compatibility tests with the specific cement and other admixtures being used, as interactions can affect performance and setting times.
! The effectiveness depends on the inhibitor's ability to migrate through the concrete pore structure, so achieving a dense, well-compacted concrete is crucial.
Standard Specification for Admixtures to Inhibit Chloride-Induced Corrosion of Reinforcing Steel in Concrete
Covers performance requirements for admixtures added to fresh concrete to inhibit corrosion.
EN 934-2:2009+A1:2012CEN (European Committee for Standardization), Europe
MediumCurrent
Admixtures for concrete, mortar and grout - Part 2: Concrete admixtures - Definitions, requirements, conformity, marking and labelling
Broad standard for all concrete admixtures, with a specific section (Type 9) for corrosion inhibitors.
ASTM G109 - 13(2018)ASTM International, USA
MediumCurrent
Standard Test Method for Determining the Effects of Chemical Admixtures on the Corrosion of Embedded Steel Reinforcement in Concrete Exposed to Chloride Environments
A key test method referenced by ASTM C1582 for performance evaluation; conceptually similar to the test in IS 14958.
Key Differences
≠IS 14958 is specifically for 'Migrating' Corrosion Inhibitors, implying functionality in both fresh and hardened concrete, whereas ASTM C1582 covers all corrosion-inhibiting admixtures for fresh concrete without distinguishing by transport mechanism.
≠The primary performance criterion in IS 14958 is a reduction in corrosion rate (via LPR) by at least 50% compared to control. In contrast, ASTM C1582 requires a much stricter reduction in total corrosion (integrated current over time) of at least 90%.
≠Test specimen geometry and conditioning differ. IS 14958 uses 'lollipop' type specimens for its electrochemical tests, while the benchmark ASTM G109 test (used for ASTM C1582) uses a prismatic concrete beam with a top rebar mat.
≠IS 14958 has more lenient setting time requirements (e.g., initial set from -90 to +120 mins of control) compared to ASTM C1582 which references ASTM C494 limits (e.g., -60 to +90 mins of control).
Key Similarities
≈All standards are performance-based, requiring a direct comparison of corrosion activity between specimens with and without the inhibitor admixture.
≈The fundamental principle of evaluation relies on electrochemical measurements (corrosion potential, corrosion current) to quantify the effectiveness of the inhibitor.
≈They all include requirements to ensure the inhibitor does not have a significant adverse effect on essential physical properties of the concrete, such as compressive strength and setting time.
≈Both IS 14958 and the equivalent international standards specify limits on the chloride ion content of the admixture to prevent it from contributing to the corrosion problem it is meant to solve.
Parameter Comparison
Parameter
IS Value
International
Source
Corrosion Inhibition Efficacy
Corrosion rate of treated specimen ≤ 50% of control specimen.
Total corrosion in treated specimens ≤ 10% of control specimens.
ASTM C1582 / C1582M - 20
Compressive Strength (28 days)
Minimum 90% of control specimen.
Minimum 90% of control specimen.
ASTM C1582 / C1582M - 20
Initial Setting Time
Between 90 min earlier and 120 min later than control.
Between 60 min earlier and 90 min later than control.
ASTM C1582 (referencing C494)
Final Setting Time
Within ± 120 minutes of control.
Between 60 min earlier and 90 min later than control.
ASTM C1582 (referencing C494)
Chloride Content of Admixture
Max 0.05% by mass of admixture.
Max 0.10% by mass of admixture (for use in prestressed/reinforced concrete).
EN 934-2:2009+A1:2012
Effect on Air Content (for non-air-entraining admixtures)
Increase shall not be more than 1.0% over control.
Shall not increase air content by more than 1.0% over control.
ASTM C1582 / C1582M - 20
⚠ Verify details from original standards before use
Key Values5
Quick Reference Values
Compressive Strength at 7 & 28 days≥ 90% of control mix
Initial Setting TimeNot more than 60 min before or 90 min after control mix
Final Setting TimeNot more than 90 min after control mix
Corrosion Current Density (icorr)≤ 10% of control specimens when tested as per Annex B
Chloride contentMax 0.05 percent by mass
Tables & Referenced Sections
Key Tables
Table 1 - Physical Requirements for Migrating Corrosion Inhibitors
Table 2 - Performance Requirements for Migrating Corrosion Inhibitors
It is a chemical admixture that, when added to concrete, migrates through the pore solution and forms a protective film on the surface of steel reinforcement to prevent corrosion.
Does using an MCI affect concrete strength?+
It should not significantly. As per Table 1, the 7 and 28-day compressive strength of concrete with the MCI must be at least 90% of the control concrete without the admixture.
How is the corrosion-inhibiting performance of an MCI evaluated?+
As per Clause 6 and Table 2, its performance is evaluated by electrochemical tests (specified in Annex B) where the corrosion current density of steel in concrete with the MCI must be 10% or less than that of the control sample.
Are there limits on setting time when using an MCI?+
Yes, according to Table 1, the initial setting time must be within -60 minutes to +90 minutes of the control mix, and the final setting time must be within +90 minutes of the control mix.