Epoxy Coated Pre-Stressed Wire Strand Testing
(Filled FBE Strand — ASTM A882/A882M)

Mechanical and coating quality testing of fusion-bonded epoxy coated and filled prestressing wire strands per ASTM A882/A882M — verifying tensile strength, 1% proof load, elongation, coating thickness, holiday detection, coating flexibility and pull-out bond strength for corrosion-critical prestressed concrete applications.

Overview

What is the Epoxy Coated Pre-Stressed Wire Strand Testing?

Epoxy Coated Pre-Stressed Wire Strands (ASTM A882/A882M) are Grade 250 or Grade 270 low-relaxation seven-wire prestressing strands with fusion-bonded epoxy (FBE) coating applied by electrostatic deposition — with the interstices between the seven wires filled with epoxy to prevent corrosive media migration by capillary action. This filled epoxy system provides the highest level of corrosion protection available for bonded post-tensioned and pre-tensioned applications in aggressive environments.

At Global Lab, epoxy coated prestressing strand testing is conducted as per ASTM A882/A882M covering coating quality (thickness ~200μm, holiday detection at 2500V — ≤2 holidays per 30m, coating flexibility/bend test) and mechanical properties (breaking load, 1% proof load, elongation at break per ASTM A416 Grade 250 or Grade 270 requirements). The filled interstice condition is verified by cross-section inspection. All results on NABL-accredited certificates.

Grade 250 & 270 Coverage

Both ASTM A416 Grade 250 (1720 MPa) and Grade 270 (1860 MPa) epoxy coated strands tested.

2500V Holiday Detection

High-voltage spark test — ≤2 holidays per 30m per ASTM A882 acceptance criteria.

Coating Thickness ~200μm

FBE coating thickness verified — ~200±50μm per ASTM A882 and FHWA guidance.

Filled Interstice Verification

Cross-section inspection confirms epoxy fill between 7 wires preventing capillary corrosion.

NABL Certified Reports

All test and calibration results are backed by traceable measurements and standardized procedures..

Coating Flexibility Bend Test

No cracking or disbonding of FBE coating on bent specimen per ASTM A882 requirements.

Test in Action

Epoxy Coated Pre-Stressed Wire Strand Testing — Site Images

Epoxy Coated Pre-Stressed Wire Strand — Filled FBE System

2500V Holiday Detection on FBE Coated Strand

Tensile Test in UTM — Breaking Load and 1% Proof Load

Test Procedure

How the Epoxy Coated Pre-Stressed Wire Strand Testing is Conducted

1

Coating Thickness Measurement

Magnetic induction gauge measures FBE coating thickness at minimum 5 points per metre on the strand sample. Results verified against ~200μm target.
2

Holiday Detection at 2500V

2500V DC spark tester passed continuously over full coated strand length. Number and location of holidays per 30m recorded — ≤2 per 30m per ASTM A882.
3

Coating Flexibility — Bend Test

Strand wound around specified mandrel. FBE coating inspected for cracking, disbonding or exposed steel after bend.
4

Tensile Test — Breaking Load, 1% Proof Load, Elongation

Strand gripped in NABL-calibrated 1000kN UTM with appropriate wedge grips. Load applied at controlled rate. Breaking load, 1% proof load and elongation at break recorded per ASTM A416.
5

Filled Interstice Check & NABL Report

Cross-section of strand cut and inspected for epoxy fill between wires. All coating and mechanical results vs ASTM A882/A416 Grade 270 requirements. NABL report within 5 days.

Standards & Specifications

Applicable Test Standards

Standard	Title	Scope	Type
ASTM A882/A882M	Standard Specification for Filled Epoxy-Coated Seven-Wire Steel Prestressing Strand	Epoxy Coated Strand	ASTM
ASTM A416/A416M	Standard Specification for Low-Relaxation Seven-Wire Strand for Prestressed Concrete	Base Strand Mechanical	ASTM
IS 6006	Specification for Uncoated Stress Relieved Strand for Prestressed Concrete	Strand Reference	Indian Standard
ASTM D3963	Standard Specification for Fabrication and Jobsite Handling of Epoxy-Coated Steel Reinforcing Bars	Epoxy Coating Reference	ASTM

Applications

Where is the Epoxy Coated Pre-Stressed Wire Strand Testing Used?

Marine and coastal bridge post-tensioning in high chloride exposure zones

Desalination plant and water treatment facility prestressed concrete structures

Offshore platform and jetty prestressed piles in aggressive marine environment

Nuclear containment structure post-tensioning requiring highest corrosion protection

Prestressed concrete tanks and reservoirs for chemical or saline liquid storage

Prestressed ground anchors and rock bolts in corrosive soil or groundwater conditions

Why Choose Global Lab

Our Advantages

NABL Accredited ReportsLegally valid ASTM A882/A882M and A416 certificates for all structural project requirements.

2500V Holiday DetectionHigh-voltage spark testing detects the finest FBE coating discontinuities — full strand length tested.

Filled vs Unfilled VerificationCross-section inspection confirms interstice fill — preventing internal capillary corrosion path.

Calibrated 1000kN UTMNABL-calibrated Universal Testing Machine with sufficient capacity for all strand diameters.

Fast 5-Day ReportComplete ASTM A882 coating and mechanical test report within 5 working days.

Pan-India CoverageMetal testing at all 7 NABL-accredited lab locations across India.

Epoxy Coated Pre-Stressed Wire Strand Testing(Filled FBE Strand — ASTM A882/A882M)