NABL Accredited · Durability Testing Service
Rapid Chloride Penetration Test
(RCPT — Chloride Permeability)
Measurement of concrete's resistance to chloride ion penetration by passing electrical current through a concrete disc — providing a rapid indicator of concrete permeability and long-term durability.
ASTM C1202
Standard
±10%
Accuracy
48hr
Report TAT
NABL
Accredited
NABL Accredited Lab · ISO/IEC 17025:2017
Digital Reports via Autovity QLMS
Pan-India · 7 Lab Locations
Est. 2009 · 20,000+ Projects
Overview
What is the Rapid Chloride Penetration Test?
The Rapid Chloride Penetration Test (RCPT) quantifies the electrical charge passed through a concrete disc specimen in 6 hours under an applied voltage of 60V. The total charge (measured in Coulombs) serves as an indicator of the concrete's resistance to chloride ion penetration, which is the primary cause of reinforcement corrosion in structures.
Conducted as per ASTM C1202 and IS 14959 Part 2, RCPT is a mandatory test for high-performance, marine, bridge deck and durability-specified concrete. Global Lab's NABL-accredited laboratory uses calibrated RCPT apparatus with continuous data logging for accurate charge measurement and classification.
Rapid 6-Hour Test
Complete chloride permeability classification in just 6 hours — faster than ponding tests.
Coulomb Classification
Charge passed (Coulombs) directly classifies concrete as high/moderate/low/very low/negligible permeability.
Mix Design Validation
Validates effectiveness of SCMs (fly ash, GGBS, silica fume) and w/c ratio on permeability.
Specification Compliance
Used to verify compliance with project durability specifications (e.g., <1000C for marine structures).
NABL Certified Reports
All results issued on NABL-accredited letterhead per ASTM C1202.
Continuous Data Logging
Full current vs. time curve recorded and reported alongside total charge.
Test in Action
Rapid Chloride Penetration Test — Site Images
RCPT Cell Assembly in Laboratory
Specimen Vacuum Saturation Process
Current-Time Curve Display During Testing
Test Procedure
How the Rapid Chloride Penetration Test is Conducted
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1Core or Cast Specimen Preparation50mm thick disc specimens are cut from 100mm diameter cores (ASTM C42) or cast cylinders. Edges are sealed with epoxy.
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2Vacuum SaturationSpecimens are vacuum-saturated with de-aerated water for 18 hours to remove entrapped air per ASTM C1202 procedure.
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3Cell AssemblyPrepared specimen is placed in the RCPT cell between two chambers — one filled with 3% NaCl (catholyte) and one with 0.3N NaOH (anolyte).
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460V Voltage Application60V DC is applied across the specimen for 6 hours. Current is recorded every 30 minutes automatically.
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5Charge Calculation & ClassificationTotal charge (Coulombs) is calculated by integrating the current-time curve. Permeability class is assigned per ASTM C1202 Table 1. NABL report issued within 48 hours.
Standards & Specifications
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| ASTM C1202 | Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration | RCPT | ASTM |
| IS 14959 Part 2 | Method of Test for Determination of Water Absorption — Concrete | Permeability | Indian Standard |
| AASHTO T277 | Rapid Determination of the Chloride Permeability of Concrete | Permeability | AASHTO |
| NT Build 492 | Chloride Migration Coefficient from Non-Steady State Migration | Migration | Nordic |
Applications
Where is the CAPO Test Used?
Acceptance testing for marine and coastal concrete structures requiring low permeability
Bridge deck concrete quality control and acceptance for NHAI projects
Validation of high-performance and durability-specified mix designs
Quality control for precast segments and elements in aggressive environments
Research and development for new concrete formulations with SCMs
Condition assessment of existing structures prior to rehabilitation
Why Choose Global Lab
Our Advantages
NABL Accredited ReportsLegally valid certificates accepted for all government and infrastructure projects.
Calibrated RCPT EquipmentAutomated RCPT apparatus with continuous data logging and NABL calibration.
Autovity Digital PlatformAccess RCPT reports and data online from any device 24/7.
Complete Durability PackageRCPT + Resistivity + Water Absorption + RCMT offered as a full durability audit.
Experienced Durability EngineersSpecialists in concrete durability for marine, bridge and industrial applications.
Fast TurnaroundTest completed in 6 hours; NABL report issued within 48 hours.